The concept: use several midrange drivers ringed around a very efficient tweeter to create a high sensitivity point source. The mids / tweeter act like a dual concentric driver (coax) without the main problem that come from loading a tweeter into a moving horn - doppler distortion. I tried 4 mids to start (the first set of measurements) and found that the tweeter was still a good 8db more sensitive. I could pad it down, but decided to try adding two more mids and that raised the sensitivity of the mids by another 3db. The second set of measurements show the on and off axis response. The results are quite good and certainly better than I expected. With the crossover set to around 1400Hz, there's no significant amount of comb filtering. and the off-axis response is excellent. Of course this is just a very roughly done test to determine whether it's worth pursuing, and what I've seen so far pretty much guarantees that. The drivers I used are the Hi-Vi B3N 90mm fullrange and the Peerless BC25SC06-04 horn loaded tweeter. Both drivers are very low cost but my initial impressions are that they sound very good. Reviews for both drivers are also very good. Is it worth doing? 6 of the B3N drivers cost less than a good quality midrange driver, but they require a much wider baffle to fit into. The most common thinking these days is that a wide baffle destroys imaging and soundstage, but I haven't found that to be a written in stone rule. I've made many different speakers of many different sizes and I can't positively say with certainty whether narrow speakers produce better a better defined soundstage. It's been my experience that speaker position plays a MUCH greater roll in how well a pair of speakers image. Also the room is a big factor, especially an excess of early reflections. And this is also at odds with the standard thinking on this today, with most saying you NEED the early reflections to produce a good soundstage. Since there are 6 midranges to install, the build is more complex. But I think that's offset at least a little bit by how interesting it looks. Looks count! I'll admit that I'm disappointed that I'm not getting a higher db output from 6 of these drivers (at the same power, each additional driver should add 3db). I thought that 4 would have come closer to the 96db output of the tweeter than they did. Some of that is from the mids operating on an open baffle and the efficiency should increase when they are enclosed in the speaker cabinet. Also, you can think of it this way: instead of one motor (magnet / voice coil) for the midrange frequencies, now there are several, which greatly increases power handling capacity and reduced the distortion associated with power compression. Also a much greater cone area translates to less cone movement to produce the same output. In other words, you get the advantages of a large speaker without the expense and other drawbacks. The mids are wired 3 in parallel x 2, and then the triplets wired in series for a total nominal impedance of around 5.3 ohms. The woofer I'll use for these speakers is an 8" Seas that has a 93db efficiency.
Tekton designs makes a few speakers like this, and they sound pretty darn good too, so maybe this isn't too bad of a design, despite the haters that don't fully understand what's going on with this design.
@@joshfoss7407 I mean… the only difference is size, weight, and material of the drivers. The design, i.e. the polycell array the drivers are in, is what Eric Alexander uses. I shouldn’t have said “patented”. Part of his patent is also written up using specific parameters on the drivers he chooses as well. But the point is that the correct terms is “drivers”. It doesn’t matter if you say tweeter, woofer, subwoofer, they’re all drivers. This dude’s using mid-woofers. Still a driver.
@@MyFatherLoves Size, weight, and material of drivers are a massive deal that would most likely invalidate an existing patent requiring a separate one. Not that it's relevant, but I'm a Tekton DI owner myself.
@@joshfoss7407 He tried to patent using an array of different drivers (see original patent application), but it wasn't allowed. What was allowed was all the drivers (center and surrounding) being the same.
I go back to the 50's and I was an early experimenter and one of the magazines, Popular Science I think if was, but not sure, did a system with 16 four or five inch speakers that they called the sweet sixteen and the array was 4x4. I had built some speakers for my "hi fi" system using "full range (Lol!)" 12 inch speakers and they sounded pretty good tho I did not have any sound measuring equipment so I doubt they were very flat at all, just sounded good to me. I had a little probably 15 watt tube amp I got from Radio Shack. So in college I got in my first band and a good PA then was not very good lol! My guitarist and I took a shop course in order to have access to the tools we needed to build our own PA. We used 6 eight inch speakers (the multi speaker systems that started to appear in the 60's weren't available yet) for each cabinet and we built two of them and used a 100 watt Bogen amp with two mike inputs built in, no EQ but that was our PA and it sounded quite good for the time. Fond memories! In the sweet sixteen article they pointed out that when you double the cone area you roughly halve the bass response, and sure enough, while it would not scare anyone today, it sounded good for then and was reasonably portable. I went on to have a fun career in music eventually owning my own studio that I ran in and amongst touring. I'm now "retired" to my Mt. cabin in NC where I make vids for my TH-cam music channel in a small studio which I built beside my cabin. It will be interesting to see how your system works out. Looks quite promising! I enjoy your vids by the way!
Very nice DIY video. Out of the measurements for on axis and 20 degree off-axis the later is more linear indicating comb filtering and cancelations since all 6 drivers are placed with equally distance between each other. Try an arrangement where you have at least 2 different distances like 5 inches and 3 inches to even out the comb filter effect and get a more linear response. Maybe like this: O O o O O O O or: O O O o O O O Since you probably have your tweeter vertically at the level of your ear spreading out midranges vertically doesn't do as much harm as spreading them out horisontally. The second setup will give a multitude of distances and a multitude of different comb filters interacting and cancel each other which hopefully will prevent bigger dips and peaks. Using two bass drivers with different distances to the floor will also help to even out the major -12dB dip you get at approx. 100-150Hz because of the 180 degree out of phase reflex you get from the floor. Look at Wilson Audio Sacha. That arrangement gives a much better bass response in the room compared to a single bass driver. To address diffraction problems I would round of edges of you cabinets with 1-2 inch radius. Otherwise edge diffraction will be a part of the equation to solve since distance between drivers and drivers and edges are quite equal. Interesting project that help to a deeper understanding... Good luck. PS. If want to try the dual bass arrangment I would suggest SB Acoustics 8" 20PFCR 8 ohm in parallell and passive radiators on the back of the cabinet (27 liter volume for each driver) or SB Acoustics 6,5" 16PFCR 8 ohm in parallell in bass reflex cabinets of 16 liters per driver. That will probably give a better end result than a single SEAS 21WO even if that is a potent driver in itself. The SB Acoustic drivers will have a matching sensitivity to let you make a design that can handle the baffle step properly.
This setup reminds me of a set of Aria coaxial speakers I had in my car in the 90's/early 2000's. The tweeter was mounted on the center post of the center post of the driver so it was "in phase" with the surrounding woofer as opposed to being mounted above the woofer like you typically see in a coaxial setup. Cool little speakers for their application.
Nice, that’s similar concept to a Tekton speaker where the tweeter is surrounded by midrange drivers. except the Tekton uses tweeters to play midrange.
The trick is to crossover as low as possible with a very good tweeter. There's a ratio formula for distances between the midranges and crossover point. Given how small they are I would think crossover at 1200 hertz should be no problem for no comb affect. So a third or fourth order on the tweeter so it's down 24 db by the Free air resonance on the tweeter so that you can crossover as low as possible. The woofers probably can handle way higher frequencies so I guess 2nd or third order? I think he is just experimenting with the drivers and they may change if he want's more sensitive or better drivers in his six midrange layout.
These HIVI drivers from parts express? I've heard many inexpensive commercial desktop speakers use this series of driver, and they are excellent. Midrange is amazing. Superb detail with just a bit of rise in the upper mid a lot like Kevlar, but no bad habits. I've been dying to see somebody try something serious with them given their under rated performance. I can imagine 6 of them have amazing transient detail with black hole levels of distortion.
I think this would be even cooler if the outer mid-range drivers were smaller to get closer to the tweeter, for example 8x 2" BMRs spaced around a 90mm tweeter waveguide.
When I first saw Tekton design loudspeakers, I had the same idea and immediately bought 8 2" BMRs to test with. 3 years later, and I still haven't gotten around to it. LOL!!!
What you wanted to say was that the outer woofer of a coaxial is phase modulating the tweeter by a low frequency cone. This is actually measurable and looks like the centre frequency has some skirts alongside it.
i have played around with those design in 3d software, nice to see someone like you make it real :) would have thought that having a digital crossover would let you play around in realtime and quicky test new things. like a mini dsp SHD studio or something.
Software like VituixCad makes designing the passive crossover fairly easy and arrives at good results, but you need to run separate measurements first to get the data it needs (unless you go with the published data). When I've used it, it got me close and then it took listening to the speaker to get it the rest of the way. For most people, close would be perfectly suitable.
Even though I don't know anything about speakers or their design, and thus didn't understand any of John's explanations, I enjoyed this video ... basically for the same reason I enjoyed watching "Super Fluffy Pancakes From Scratch" video from 7 years ago, which can also be found on this channel from its former incarnation
Interesting. Monitor Audio's new $95 grand Hyphn flagships have this layout but perhaps in a slightly smaller form factor (plus a bunch of woofers etc of course).
Like tekton speaker design, but they using tweeter for midrange.. the idea is to have low mass in midrange single tweeter alone cannot produce midrange properly.. but when combining with more tweeter they have more power handling to produce mid area..
There are also 1.5"-2" mid range drivers (cause rare dom tweeters can play below 2kHz). I think they would be also great for that. Now when I see a loudspeaker that has like 6" for a mid range, I say meh. Despite it has a flat FR say to 5kHz. No way.
Liked and subbed. 1st video of yours I've seen. Definitely going to be watching more of your videos. I'd like to see you try putting a Ribbon Tweeter in one of these COAX designs.I'm a sucker for the highs from the ribbon transducers of the Adam Audio monitors. A buddy in 1974 had a pair of Heil speakers with the Air Motion Transducer sitting on top of each cabinet.The Adam's design is from the Heil designer. Mind Blowing at the time,to say the least. Been listening to a pair of powered Presonus S-8 COAX monitors for the last 10 years. And a bunch of different studio monitors in that timeframe that have come and gone.The soundstage and imaging with the S-8's in my small studio is amazing. Monitors are slightly off axis. Neil Pearts drums hang in the air between the monitors. Looking forward to seeing this current project in a cabinet. I would like to build a pair of my own monitors. Best Regards. 👍 👍
Fascinating stuff. Collecting info so I’m ready to take the leap. Do you have a video on woofer (not subwoofer) box and crossover design? I like/love the open baffle idea. I’m a hobbyist with a full on workshop. I’ve made such a diversified array of projects, speakers aren’t any stretch for me. Thanks
I've seen cluster speakers that are a similar concept. Typically they are 9 midranges in a square pattern with a tweeter located near the center. The have a following from what I understand. I have not heard them myself though.
Go DIY! However, Eric Alexander would like to have a word with you. Otherwise, as implemented in his speakers, the sound is nothing short of amazing. I'm a fan of line arrays and planar configurations, his Moab is 6ft of this in an MTM configuration which sounds fantastic. The majority of his speakers use this midrange driver configuration (MTMs using all as midrange in the cluster, and non MTM having the middle driver covering the high frequencies...
At least this design doesn't infringe on Eric's patent, which only covers the center driver being identical to the surrounding ones. Oh, he tried to patent different drivers in his original application, but apparently, that didn't stick (I'm guessing there was prior art). The one advantage Eric has is that he can reduce the cost by stocking only one style of tweeter to build his speakers. If one were to surround the center tweeter with more tweeters (instead of midranges), and those tweeters are a different style, there still would be no infringement on Eric's patent.
@@abboberg I ignored the actual patent discussion on purpose. He doesn't use the same tweeter across the board. Depends on the model. I was hoping this DIY was going to be open baffle because that would be interesting. There's something special and effortless about the midrange from the Moab for instance. Magnepan is pretty explicit about the weight of their drivers as well, that's a huge factor. I love the sound of both types. It will be interesting to hear impressions when this is done. I'm a Tekton customer (I'd most likely buy through them/him again if I had the need), and I'm puzzled at how one patents the arrangement of off the shelf parts. I haven't looked into the patent(s) -- I just care about how the music flow through the damn things to my ears.
Patents are not applicable for this because I'm not going into production or producing plans for the design. That's what a patent is for - documentation to help stop a competitor from stealing a design to sell. To enforce a patent, you need to sue (in court) the alleged patent infringer, and that, my friends, is insanely expensive. And in the suit you have to show a clear breach of the patent, as in the original design was employed and units that will be sold were produced. The goal of a patent suit is to stop production and recoup any damages that were done because a rival product was taking market share away from the original. On top of that, my take on this (as mentioned above) isn't the same as the original design, which uses tweeters instead of midranges. Other speaker manufacturers have already done this and marketed their products.
@@tupuhumuhumunukunukuapuaa3093 Well, you are not avoiding the whole patent discussion by saying he doesn't use the same tweeter across the board. Of course he is not going to violate any patent when using a different driver in the middle versus the surrounding drivers - that is not in his patent and is likely prior art since he actually tried to patent that in his original application. What his patent morphed into is a "cost reduction patent", which is what he clearly did not want, originally. It is cheaper to not have different drivers in this array. However, the spirit of his patent is still there - having the surrounding tweeters act as a concentric midrange since they aren't working that hard and sharing the load amongst themselves. As far as the sound - I've heard that the speakers are very directional - is that your experience?
@@IBuildIt If the patent were applicable (and it's not, clearly), you would still be infringing, and he could sue you to stop making them. You can't just blur the lines between high-volume production and low-volume production (making some for you and your friends) - infringement is still infringement, no matter how many you make. Sorry.
Using a coax that is crossed high enough to keep xmax as low as reasonable negates the doppler effect. This has been proven very well by Andrew Jones and in particular his Mofi 8 and 10" designs. I've also done this with great effect using a Seas 6" coax mated to a pr of 8" Dayton woofers. Crossed at 300hz, xmax was kept to less than 1mm on the coax.
True, but good quality coax drivers aren't cheap and by pushing the crossover point up, you undo some of the advantage of using a point source to begin with. I think you can get all of these drivers for two speakers for the cost of one Seas coax. Also using several drivers instead of one means there are several motors sharing the power required.
Looks like the outer drivers are about 0.2 meters apart center to center. That's pretty far apart for midrange drivers. So speed of sound 343 m/s and half a wave at 0.2 meters, 343 / .2 / 2 = 857.5 Hz . If I did the math correctly, I expect you will see a 20 * log10(.33) = 9.6 dB dip in the response with a sealed box at 90 degrees dispersion angle at 858 Hz due to the driver spacing cancelation. The 0.33 is from the outer drivers canceling each other, so only two of the six drivers will radiate at 90 degrees. You could smash the outer drivers closer to the tweeter horizontally to bring this frequency up a bit. I've been playing with a matrix arrangement of 2" midranges two wide and three tall. That works well up to 2,500 Hz. I recently decided that a speaker with a nearly flat response 90 degrees off axis is what I really like. I gave up on using HiVi drivers as they had limited Xmax and high distortion before they reached Xmax. I was initially attracted to them by the ruler flat response in the data sheet. They don't publish distortion figures for a reason. You might look at the Aurasound Whisper 2" instead. They are amazing. Go get a miniDSP digital crossover and you can save a lot of time and get much better results. Go download Visaton free Boxsim software from their website. Enter that design and see the wild variation in the directivity with frequency. It maybe an entertaining speaker, but I don't know anyone saying, let's have wild swings in directivity and then designing a speaker to achieve that.
Great project! Been considering something similar for over 10 years myself, but never get around to it. Was going to encircle a planar driver with some small midbass drivers. I wonder if your measurement labels are incorrect or something btw measurement sweeps got altered. There's no way that the above 7K response ON AXIS should be lower than off axis. And the smoothing of the orange line looks more than the green and blue. In any case, looking forward to further progress.
I promised myself this a few years ago - that I'd gift myself the indulgence of getting back into the hobby after pumping out woodworking content for 10 years on TH-cam. Too bad that I'm working from a channel that wasn't built on audio projects from the start. Too many subs that aren't watching the new videos when they come out equals no chance of having my videos recommended to the people who would watch them.
How about a MEH? It does nearly the same thing but it's even more of a point source as the speakers are bunched up together. The cancellation from the back wave bouncing from the throat affects ALL distortion above the passband of each driver, which eliminates all harmonics outside of it unlike in a conventional speaker, where each cone plays all it's harmonics. This means that distortion is virtually inaudible except for the lowest harmonics of the lowest tones of each driver (which are not necessarily unpleasant) and the distortion doesn't rise with SPL like it does on drivers on a flat baffle. Also time aligning of the response is nearly constant across ~50* in front of the speaker. Being a horn it doesn't have much output outside of it's beam. It basically behaves like one driver but without any distortion. Four inexpensive 3" pro audio transducers don't need to look nice, so they cost less. Sensitivity is high because of horn loading. Construction is tricky because of all the trapeze parts and angled but the enclosure is also more stiff thanks to natural bracing of a pyramid horn. The main downside is very wobbly frequency response.
I was gonna do something similar to that in a Dodge Shadow Turbo... the car never lasted long enough for me to complete the audio ambitions I had for that car. I WAS gonna build out the door panel to basically do the same thing...but in a car.
This is the first video I have watched from this channel. I was very impressed and subscribed before it finished. Some of your explanations on why/ proposed benefits of this design would also apply to the tekton speakers. I’ve watched a bunch of different people including every thing tekton published, and I believe you have explained some things not mentioned before and did it in a easy to follow manner. I look forward to watching more of your stuff and hope it’s all this good.
I had the same idea a while back but with the tectonic 2in bmr... Who knows might try it some day 😅.. think my inspiration came from the xtz cinema speakers that use multiple smaller tweeters to act as a single big one... got me thinking that maybe i could get a near full range experience with a simple design... which was only simple in my head😂😂
The membranes in your concept do move as well alike a typical coax-speaker. The difference? Your set up does not as much work like a waveguide, but there are still cones, alternating sound coming from the tweeter. If a tweeter beams like here, beacause it is a horn loaded dome, this would be the same with the typical Tannoy-Speakers, that use a horn-tweeter in the middle of a huge cone (12" or 15" for example). In this case, the doppler-effect, if hearible (what I doubt) at all, will be minimized.
Do you think that these circular speakers arrays can or could ever behave like a very large woofer, maybe like a virtual woofer of the same diameter as the array? My inspiration for this thought is very large array radio telescopes, but in reverse.
Now I’m waiting to see a video with 12 of those woofers surrounding these mids for a true coax design. But where would you get a sheet of plywood that large? I’m sure you could figure it out.
I wonder if an odd number of mid-range drivers ( like five ) would be better. Five would have less symmetry and thus results in weaker resonance fields both in the far field and in the box.
At least one of the issues with any odd number of drivers (above 1) operating over the same bandwidth would be the net reactive impedance load, which it drops low enough could cause more than a little bit of grief to many amplifiers- hence, I think John’s wiring configuration of two series wired sets of paralleled triplets.
@@gregs7918 Parallel wiring is simpler for most folks to understand and implement, but it can very quickly reduce the net impedance load to dangerously low levels. While I never like to presume the expertise of others, keep in mind that the “rated impedance” of any individual model of moving coil driver is a nominal figure that will vary with frequency, often to well below half the rated figure. It’s that phenomena, along with the complex capacitive and inductive reactance of filter / crossover networks that if not carefully considered can cause conniption fits in amplifiers. Electronics with well designed protection circuits may save themselves, but damage to either the load or driving devices should always be a concern. In my 20 or so years of DIY speaker building, I never implemented an array of more than 4 drivers of the same type in a design - most commonly as two pairs of small mid-bass units in a bipolar side firing configuration- and as they were generally “8ohm” models, a simple parallel/ series was easily accomplished. It also made for relatively simple modelling of passive crossover networks. Commercial manufacturers with sufficient order volumes can specify their own proprietary parameters from driver foundries, including higher impedances that would allow for a greater number to be run in parallel. Of course, if one were to throw enough resources at the design and go fully active with single amp channel per driver, then many of the above noted concerns become moot.
Biggest difference would be how difficult it would be to do that. The baffle would have to be machined to tilt each driver, yet have them sitting flat to make a good seal. That alone would make it impractical, unless I could be sure that the results would be beneficial.
@@IBuildIt You could do a series of pointed segments with compound angles on the edges. In contrasting woods it would look interesting and seems to be right in your wheelhouse. No idea if it would improve the off axis, but maybe you could mock up a test with some driver wedges to put on your test baffle to see what the results might be. I wonder if simulation software could give a clue? Just an idea based on what you got from your tests.
Im just Curious what is the connection of these speakers? Series Parallel mono? Parallel connection Stereo on one baffle? Please enlighten me a bit Confuse😢 how are these speakers wired and powered, thanks
92 dB on axis at 13k and 84 dB at 20k (Almost half as loud). Looks like another tweeter or two or at least one with more high frequency response is needed. Pretty good from the low end to the mids though. Cool looking design.
That's the typical drop-off you get from horn loading a tweeter. Since I can't hear above 11k anyway (and there's not much musical content up there either), it's not something that needs fixing.
@@IBuildIt I am fortunate enough to still hear to 17,500 Hz in one ear, and 17,000 Hz in the other ear. So yeah, high frequencies that roll off before that sound like listening to music with a pillow over my head. LOL. But hey, if 20-11,000 Hz is good for you, more power to you.
I've got an old Energy Center Channel with a tweeter and two mids flanking it diagonally and back in the day when the experts tested it, apparently it had almost no change from on axis to off axis, (or so wide that it wouldn't be an issue in standard application). I wonder if two mids would work as good, or better than 4, or 6? Lots of the vintage speakers employed two mids. Love the videos!
Thanks! I need the extra drivers to push up the sensitivity to match the tweeter. Using just two would mean I'd have to pad the tweeter down a good 12-15db.
@@IBuildIt lol... That's right you mentioned that in the video and I sort of forgot it thinking about the possibilities of the general arrangements. Maybe a less efficient tweeter or more efficient mids. Interesting experiments and I'm interested to see how it goes. I've seen some super high end boutique speakers in videos that look like that. The one thing that I don't understand, is that usually the Mid-Range is hotter than everything else and our ears are more inclined to be more sensitive in that range, so I'm not clear on why more Midrange is better, or how it's not negatively impacted by comb filtering and cancellation. I've got a couple old Jensen projects coming up that have the dual mids, spread far apart and at different heights with the tweeter sort of centered and nested in-between, but up a little higher... Pretty sure I'm going to use pro drivers for one or both projects. I was considering using one of the holes for a port, but it would throw off the cool retro look.
Donald North Audio has a better/moreover fully realized version of this that further considers the baffle edges and also has an open baffle woofer section
Great idea. Maybe the 3" dome mids would be even better for this application. Also do you think non horn/waveguide loaded tweeters won't work? As the dispersion would be too wide & interfere with the cones?
I've built speaker boxes, but never had the equipment or know how to tune them. Do you have any recommendations on where to get started on how to learn those things? Thank you.
How come you don't use things like desidamp to improve the sound quality? It's brilliant, especially used as a sandwich of thin layers of canceling the rebounded sound effecting the end result at all.
Very cool experiment: Point source, high efficiency, and good power handling. What happens with a small delay to outer drivers to make a spherical wavefront (like Quad used to do with the ESL 63)? Or perhaps better, if drivers are actually on a hemisphere? With your woodworking skills this could be visually stunning.
Very surprising lack of cancellation when off-axis horizontally. I wonder if the three vertical pairs formed by your particular array serve to suppress some of it.
If you look at Augspurger specs, they do a 5" 16 ohm 500Hz - 20K Hz horn over an 8ohm 10 or 12" mid bass for 200 - 500hz, then a 4 ohm 12 or 15" sub for 20 - 2 or 300Hz. With an awesome DSP set up. Roughly. I highly recommend looking into these. They are current recording studio standard. Amazing what they do with EQ and phase issues. I learned a lot from these guys.
People largely rubbish this kind of thing, but as long as spacing to wavelength is within spec it's actually really a good design, like yours, and the measurements are telling you such.👍🙂 Are those M4N's?
Off axis and on axis plots don't seem to correlate with each other very well. If they are, then you don't have any interferences and diffraction. You most likely have a good amount of destructive interference going on... but again, once you get to a serious point, these issues could be resolved. Congratulations!
Here is an Idea Id like to see you try with this: Have a unique crossover for each of these midrange drivers... separating them, so that Each driver only gets a fraction of the total Midrange spectrum. Why? When you play music that has a lot of different instruments and vocals all playing at the same time... the drivers will often end up suffering some Distortions.. as it cant easily keep up with how much demand is being placed upon it (especially low strength drivers). But when you split the workload up... there is far less chance of any distortions taking place. Each driver will than be MUCH cleaner and defined, with Far less potential for ANY distortions at all. I actually realized this issue, when I was using my Pioneer surround sound amp. I normally only ran it in 4 channel mode... but when I tested the center channel.. I found that the left and right speakers were playing the movies music... so much cleaner and clearer. That was because most of the vocals were being shifted to the center channel... taking some of the Burdon off of the other speakers. It would also be good to put in at least two woofers, and do the same thing with them. Half the frequency ranges for each of them, so that they both have less workload, and thus, much less potential for distortions. Im guessing you will use Open Baffle for the woofers.. but if closed.. Try putting in Passive Radiators on three sides of the cabinet (Left, Rear, and Right). As for Midranges... Im sure those are decent... but the best Midranges Ive ever heard, were 3 inch Domes. And it would be fantastic if you tried EPI Inverted Tweeters, from the Humanspeakers website. Ive never experienced a Wider Soundstage, by any other tweeter.
I'm thinking it may be interesting to run a test where the top three mids cover the upper midrange, say from 900Hz to 1800Hz, then have the lower three cover the range from 300Hz to 900Hz. But this idea that the music is complex is mostly a misconception of what's going on. The speakers respond to a single electrical signal, as in if you slice it at a single point you will get a single voltage. The way we perceive music is that several difference frequencies are playing at once, and while that is true, the signal that results from that is still just a series of different voltages that drive the speakers. Those multiple frequencies get translated to the language the speaker needs to produce sound - a range of voltages.
@@IBuildIt Nice to hear that you may try this. Of course the Music is Voltages... but.. its still a bit more complex than that. Those voltages are then translated into Mechanical Movement... and this is where the Distortions can come into play. If there is a single frequency being represented... that is very easy for a speaker to replicate... as its just a simple vibrational pattern / wave. But where multiples frequencies are happening all at once... there can be limits as to how well the drivers can mechanically duplicate all of them, faithfully... all at the same time. Obviously, the strength of the magnetic forces are a big factor... as if the driver cant accelerate fast enough to keep up with the signals changes... they will be some degree of loss in the expelled sound. This is why higher end Drivers, cost much more... even while they appear to have the same frequency output capabilities. The use of larger and stronger magnets... special "stronger but lighter" cone materials, higher precision tolerances.. such as less spacing between the coil and the magnet gap, and some other factors that Im likely not even aware of. Higher frequency drivers seem to suffer less from distortions than woofers... due to a much smaller cone size / mass. But... they also are handling a LOT more of the complex workloads... and at much higher rates of speeds... so any tiny amount of distortion, will be quite impactful. Anyways... I have a Theory that Bose was doing this Split Frequency method, OR is quickly alternating the signal between two or more drivers. In this way, they are still greatly reducing the overall workload demands on each single driver... and the switching would be fast enough, that nobody would audibly be able to Hear the alternating switching between each driver. Actually... This was somewhat similar to how the original surround sound amps functioned. Every Nth of a second... they would take part of the audio signal... and throw it to the rear speakers. In fact, you might also consider trying both methods at the same time. Where you split the frequency demands between a pair of drivers.. AND you alternate between two or more different Pairs of drivers. Obviously, this would be a lot more complex to build the required electronics, to accomplish. Anyway... this is one of the reasons why I dont care for mere "Sweep" data... because a lot of speakers can replicate a simple singular sweep of frequency changes, without any Distortions. Its when you are playing very complex frequencies all at the same time... and at maximum volume levels... where the distortions will end up being noticed. I dont know how they Measure Distortion levels in speakers / headphones... But I would imagine that you would actually need to play some complex music through them, at loud volume levels... and analyze the Entire music track, compared against the original signals. The changes might be very small on a graph, and so there must be some sort of automatic computerized analyzation routine, that figures out the exact percentage of distortion issues. (of course.. your ears will often easily be able to hear muddying of certain sounds)
Okay so probably a very stupid question but i have been geting very mixed messaging from the articals i read. Can you make a open baffle speaker with a speaker made as a in wall infinite baffle. Like are the speaker units essentially the same and its just the design of the housing thats the difference or do you have to get speakers more made for this set up.
The drivers are too big and the spacing is too far apart, try 5.25" drivers or smaller and get them as close as possible to reduce the cancelling. This idea solves some issues but creates others. Very powerful however.
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The concept: use several midrange drivers ringed around a very efficient tweeter to create a high sensitivity point source. The mids / tweeter act like a dual concentric driver (coax) without the main problem that come from loading a tweeter into a moving horn - doppler distortion.
I tried 4 mids to start (the first set of measurements) and found that the tweeter was still a good 8db more sensitive. I could pad it down, but decided to try adding two more mids and that raised the sensitivity of the mids by another 3db. The second set of measurements show the on and off axis response.
The results are quite good and certainly better than I expected. With the crossover set to around 1400Hz, there's no significant amount of comb filtering. and the off-axis response is excellent.
Of course this is just a very roughly done test to determine whether it's worth pursuing, and what I've seen so far pretty much guarantees that.
The drivers I used are the Hi-Vi B3N 90mm fullrange and the Peerless BC25SC06-04 horn loaded tweeter. Both drivers are very low cost but my initial impressions are that they sound very good. Reviews for both drivers are also very good.
Is it worth doing?
6 of the B3N drivers cost less than a good quality midrange driver, but they require a much wider baffle to fit into. The most common thinking these days is that a wide baffle destroys imaging and soundstage, but I haven't found that to be a written in stone rule. I've made many different speakers of many different sizes and I can't positively say with certainty whether narrow speakers produce better a better defined soundstage. It's been my experience that speaker position plays a MUCH greater roll in how well a pair of speakers image. Also the room is a big factor, especially an excess of early reflections. And this is also at odds with the standard thinking on this today, with most saying you NEED the early reflections to produce a good soundstage.
Since there are 6 midranges to install, the build is more complex. But I think that's offset at least a little bit by how interesting it looks. Looks count!
I'll admit that I'm disappointed that I'm not getting a higher db output from 6 of these drivers (at the same power, each additional driver should add 3db). I thought that 4 would have come closer to the 96db output of the tweeter than they did. Some of that is from the mids operating on an open baffle and the efficiency should increase when they are enclosed in the speaker cabinet.
Also, you can think of it this way: instead of one motor (magnet / voice coil) for the midrange frequencies, now there are several, which greatly increases power handling capacity and reduced the distortion associated with power compression. Also a much greater cone area translates to less cone movement to produce the same output. In other words, you get the advantages of a large speaker without the expense and other drawbacks.
The mids are wired 3 in parallel x 2, and then the triplets wired in series for a total nominal impedance of around 5.3 ohms.
The woofer I'll use for these speakers is an 8" Seas that has a 93db efficiency.
Interesting idea, I hole you'll share the final result of the project and it would be great also a sound test ;)
Very interesting! I’ve seen commercial speakers with this layout but wondered about interactions between the drivers. Thanks for sharing!
Thank you for having the courage to experiment and the time and talent to documents more or less
Tekton designs makes a few speakers like this, and they sound pretty darn good too, so maybe this isn't too bad of a design, despite the haters that don't fully understand what's going on with this design.
Such an ingenious design. Patented by Eric Alexander at Tekton.
Tekton's version uses tweeters, so this is quite different.
@@joshfoss7407 I mean… the only difference is size, weight, and material of the drivers. The design, i.e. the polycell array the drivers are in, is what Eric Alexander uses. I shouldn’t have said “patented”. Part of his patent is also written up using specific parameters on the drivers he chooses as well.
But the point is that the correct terms is “drivers”. It doesn’t matter if you say tweeter, woofer, subwoofer, they’re all drivers. This dude’s using mid-woofers. Still a driver.
@@MyFatherLoves Size, weight, and material of drivers are a massive deal that would most likely invalidate an existing patent requiring a separate one. Not that it's relevant, but I'm a Tekton DI owner myself.
@@joshfoss7407 He tried to patent using an array of different drivers (see original patent application), but it wasn't allowed. What was allowed was all the drivers (center and surrounding) being the same.
@@abboberg Right, because that's how patents work. You can't patent a concept, it has to be a specific execution.
I go back to the 50's and I was an early experimenter and one of the magazines, Popular Science I think if was, but not sure, did a system with 16 four or five inch speakers that they called the sweet sixteen and the array was 4x4. I had built some speakers for my "hi fi" system using "full range (Lol!)" 12 inch speakers and they sounded pretty good tho I did not have any sound measuring equipment so I doubt they were very flat at all, just sounded good to me. I had a little probably 15 watt tube amp I got from Radio Shack. So in college I got in my first band and a good PA then was not very good lol! My guitarist and I took a shop course in order to have access to the tools we needed to build our own PA. We used 6 eight inch speakers (the multi speaker systems that started to appear in the 60's weren't available yet) for each cabinet and we built two of them and used a 100 watt Bogen amp with two mike inputs built in, no EQ but that was our PA and it sounded quite good for the time. Fond memories! In the sweet sixteen article they pointed out that when you double the cone area you roughly halve the bass response, and sure enough, while it would not scare anyone today, it sounded good for then and was reasonably portable. I went on to have a fun career in music eventually owning my own studio that I ran in and amongst touring. I'm now "retired" to my Mt. cabin in NC where I make vids for my TH-cam music channel in a small studio which I built beside my cabin. It will be interesting to see how your system works out. Looks quite promising! I enjoy your vids by the way!
Thanks! Great story.
Very nice DIY video. Out of the measurements for on axis and 20 degree off-axis the later is more linear indicating comb filtering and cancelations since all 6 drivers are placed with equally distance between each other. Try an arrangement where you have at least 2 different distances like 5 inches and 3 inches to even out the comb filter effect and get a more linear response.
Maybe like this:
O O
o
O O
O O
or:
O
O O
o
O O
O
Since you probably have your tweeter vertically at the level of your ear spreading out midranges vertically doesn't do as much harm as spreading them out horisontally.
The second setup will give a multitude of distances and a multitude of different comb filters interacting and cancel each other which hopefully will prevent bigger dips and peaks.
Using two bass drivers with different distances to the floor will also help to even out the major -12dB dip you get at approx. 100-150Hz because of the 180 degree out of phase reflex you get from the floor. Look at Wilson Audio Sacha. That arrangement gives a much better bass response in the room compared to a single bass driver.
To address diffraction problems I would round of edges of you cabinets with 1-2 inch radius. Otherwise edge diffraction will be a part of the equation to solve since distance between drivers and drivers and edges are quite equal.
Interesting project that help to a deeper understanding...
Good luck.
PS. If want to try the dual bass arrangment I would suggest SB Acoustics 8" 20PFCR 8 ohm in parallell and passive radiators on the back of the cabinet (27 liter volume for each driver) or SB Acoustics 6,5" 16PFCR 8 ohm in parallell in bass reflex cabinets of 16 liters per driver.
That will probably give a better end result than a single SEAS 21WO even if that is a potent driver in itself.
The SB Acoustic drivers will have a matching sensitivity to let you make a design that can handle the baffle step properly.
IMHO visually the 6 speaker looks so much better than 4 config. I enjoy this speaker content even if I don't plan to make anything custom.
Thanks! I like the look of the 6 better as well.
It's almost like Tekton knows what they are doing.
Tekton has been making speakers with this array for years. I own a set
This setup reminds me of a set of Aria coaxial speakers I had in my car in the 90's/early 2000's. The tweeter was mounted on the center post of the center post of the driver so it was "in phase" with the surrounding woofer as opposed to being mounted above the woofer like you typically see in a coaxial setup. Cool little speakers for their application.
Elac did something similar a few years ago with the Uni-Fi. They sound fantastic.
Explains why my tweeters are mounted over the top of the woofer on brackets. (Bose 42)
Nice, that’s similar concept to a Tekton speaker where the tweeter is surrounded by midrange drivers. except the Tekton uses tweeters to play midrange.
The difference is he was gonna use 4 first then switched to 6
@@dilbyjones Tekton has a 4 and 6 midrange arrangement as well.
The trick is to crossover as low as possible with a very good tweeter. There's a ratio formula for distances between the midranges and crossover point. Given how small they are I would think crossover at 1200 hertz should be no problem for no comb affect. So a third or fourth order on the tweeter so it's down 24 db by the Free air resonance on the tweeter so that you can crossover as low as possible. The woofers probably can handle way higher frequencies so I guess 2nd or third order? I think he is just experimenting with the drivers and they may change if he want's more sensitive or better drivers in his six midrange layout.
Wahnsinn, wie John versucht ausschließlich durch's Reden einen Klang zu vermitteln; ich bin begeistert!
These HIVI drivers from parts express? I've heard many inexpensive commercial desktop speakers use this series of driver, and they are excellent. Midrange is amazing. Superb detail with just a bit of rise in the upper mid a lot like Kevlar, but no bad habits. I've been dying to see somebody try something serious with them given their under rated performance. I can imagine 6 of them have amazing transient detail with black hole levels of distortion.
I think this would be even cooler if the outer mid-range drivers were smaller to get closer to the tweeter, for example 8x 2" BMRs spaced around a 90mm tweeter waveguide.
When I first saw Tekton design loudspeakers, I had the same idea and immediately bought 8 2" BMRs to test with. 3 years later, and I still haven't gotten around to it. LOL!!!
@conchobar Haha years ago I bought 6 midrange and 6 tweeters and they are still on my shelf. Life gets in the way.
I had the same thought. If you use more smaller mid drivers could it sound better? When do you reach diminished returns?
You're absolutely fabulous. Thank you
What you wanted to say was that the outer woofer of a coaxial is phase modulating the tweeter by a low frequency cone. This is actually measurable and looks like the centre frequency has some skirts alongside it.
Tekton speaker - plus. Great idea and work Mr. Heisz!
i knew i had seen something like this before but couldn't remember what/where.
i have played around with those design in 3d software, nice to see someone like you make it real :)
would have thought that having a digital crossover would let you play around in realtime and quicky test new things. like a mini dsp SHD studio or something.
By the time I get around to building these, my 10 channel amp will be finished and that will replace the minidsp I'm using in my listening room.
Software like VituixCad makes designing the passive crossover fairly easy and arrives at good results, but you need to run separate measurements first to get the data it needs (unless you go with the published data). When I've used it, it got me close and then it took listening to the speaker to get it the rest of the way. For most people, close would be perfectly suitable.
Hello folks:
As always you gets us thinking.
In nature many flowers have five points pentagram.
Geometrical patterns.
Ride Easy
Even though I don't know anything about speakers or their design, and thus didn't understand any of John's explanations, I enjoyed this video ... basically for the same reason I enjoyed watching "Super Fluffy Pancakes From Scratch" video from 7 years ago, which can also be found on this channel from its former incarnation
Interesting. Monitor Audio's new $95 grand Hyphn flagships have this layout but perhaps in a slightly smaller form factor (plus a bunch of woofers etc of course).
Like tekton speaker design, but they using tweeter for midrange.. the idea is to have low mass in midrange single tweeter alone cannot produce midrange properly.. but when combining with more tweeter they have more power handling to produce mid area..
There are also 1.5"-2" mid range drivers (cause rare dom tweeters can play below 2kHz). I think they would be also great for that. Now when I see a loudspeaker that has like 6" for a mid range, I say meh. Despite it has a flat FR say to 5kHz. No way.
Looks like Tekton's tweeter array - creating an acoustical wave guide.
That's what I thought of, too. Tekton's **patented** array.
@@svalbard01 a patent on a similar implementation doesn't prevent anyone else from making similar products.
Liked and subbed. 1st video of yours I've seen. Definitely going to be watching more of your videos. I'd like to see you try putting a Ribbon Tweeter in one of these COAX designs.I'm a sucker for the highs from the ribbon transducers of the Adam Audio monitors. A buddy in 1974 had a pair of Heil speakers with the Air Motion Transducer sitting on top of each cabinet.The Adam's design is from the Heil designer. Mind Blowing at the time,to say the least. Been listening to a pair of powered Presonus S-8 COAX monitors for the last 10 years. And a bunch of different studio monitors in that timeframe that have come and gone.The soundstage and imaging with the S-8's in my small studio is amazing. Monitors are slightly off axis. Neil Pearts drums hang in the air between the monitors. Looking forward to seeing this current project in a cabinet. I would like to build a pair of my own monitors. Best Regards. 👍 👍
That driver arrangement is known as “Flower array”.
It's good to have fun! Thanks for sharing yours.
The driver's output is "coupled" when mounted close together, effectively making it project like one big driver.
Very interested to see the project going further!!! I would use active crossover.
I totally agree. You get so much more real time control.
Fascinating stuff. Collecting info so I’m ready to take the leap. Do you have a video on woofer (not subwoofer) box and crossover design? I like/love the open baffle idea. I’m a hobbyist with a full on workshop. I’ve made such a diversified array of projects, speakers aren’t any stretch for me. Thanks
I've seen cluster speakers that are a similar concept. Typically they are 9 midranges in a square pattern with a tweeter located near the center. The have a following from what I understand. I have not heard them myself though.
Go DIY! However, Eric Alexander would like to have a word with you. Otherwise, as implemented in his speakers, the sound is nothing short of amazing. I'm a fan of line arrays and planar configurations, his Moab is 6ft of this in an MTM configuration which sounds fantastic. The majority of his speakers use this midrange driver configuration (MTMs using all as midrange in the cluster, and non MTM having the middle driver covering the high frequencies...
At least this design doesn't infringe on Eric's patent, which only covers the center driver being identical to the surrounding ones. Oh, he tried to patent different drivers in his original application, but apparently, that didn't stick (I'm guessing there was prior art). The one advantage Eric has is that he can reduce the cost by stocking only one style of tweeter to build his speakers. If one were to surround the center tweeter with more tweeters (instead of midranges), and those tweeters are a different style, there still would be no infringement on Eric's patent.
@@abboberg I ignored the actual patent discussion on purpose. He doesn't use the same tweeter across the board. Depends on the model. I was hoping this DIY was going to be open baffle because that would be interesting. There's something special and effortless about the midrange from the Moab for instance. Magnepan is pretty explicit about the weight of their drivers as well, that's a huge factor. I love the sound of both types. It will be interesting to hear impressions when this is done.
I'm a Tekton customer (I'd most likely buy through them/him again if I had the need), and I'm puzzled at how one patents the arrangement of off the shelf parts. I haven't looked into the patent(s) -- I just care about how the music flow through the damn things to my ears.
Patents are not applicable for this because I'm not going into production or producing plans for the design. That's what a patent is for - documentation to help stop a competitor from stealing a design to sell.
To enforce a patent, you need to sue (in court) the alleged patent infringer, and that, my friends, is insanely expensive. And in the suit you have to show a clear breach of the patent, as in the original design was employed and units that will be sold were produced. The goal of a patent suit is to stop production and recoup any damages that were done because a rival product was taking market share away from the original.
On top of that, my take on this (as mentioned above) isn't the same as the original design, which uses tweeters instead of midranges. Other speaker manufacturers have already done this and marketed their products.
@@tupuhumuhumunukunukuapuaa3093 Well, you are not avoiding the whole patent discussion by saying he doesn't use the same tweeter across the board. Of course he is not going to violate any patent when using a different driver in the middle versus the surrounding drivers - that is not in his patent and is likely prior art since he actually tried to patent that in his original application. What his patent morphed into is a "cost reduction patent", which is what he clearly did not want, originally. It is cheaper to not have different drivers in this array. However, the spirit of his patent is still there - having the surrounding tweeters act as a concentric midrange since they aren't working that hard and sharing the load amongst themselves. As far as the sound - I've heard that the speakers are very directional - is that your experience?
@@IBuildIt If the patent were applicable (and it's not, clearly), you would still be infringing, and he could sue you to stop making them. You can't just blur the lines between high-volume production and low-volume production (making some for you and your friends) - infringement is still infringement, no matter how many you make. Sorry.
Using a coax that is crossed high enough to keep xmax as low as reasonable negates the doppler effect. This has been proven very well by Andrew Jones and in particular his Mofi 8 and 10" designs. I've also done this with great effect using a Seas 6" coax mated to a pr of 8" Dayton woofers. Crossed at 300hz, xmax was kept to less than 1mm on the coax.
True, but good quality coax drivers aren't cheap and by pushing the crossover point up, you undo some of the advantage of using a point source to begin with. I think you can get all of these drivers for two speakers for the cost of one Seas coax.
Also using several drivers instead of one means there are several motors sharing the power required.
Very interesting design
This will be a great video when complete
Looks like the outer drivers are about 0.2 meters apart center to center. That's pretty far apart for midrange drivers. So speed of sound 343 m/s and half a wave at 0.2 meters, 343 / .2 / 2 = 857.5 Hz . If I did the math correctly, I expect you will see a 20 * log10(.33) = 9.6 dB dip in the response with a sealed box at 90 degrees dispersion angle at 858 Hz due to the driver spacing cancelation. The 0.33 is from the outer drivers canceling each other, so only two of the six drivers will radiate at 90 degrees. You could smash the outer drivers closer to the tweeter horizontally to bring this frequency up a bit. I've been playing with a matrix arrangement of 2" midranges two wide and three tall. That works well up to 2,500 Hz. I recently decided that a speaker with a nearly flat response 90 degrees off axis is what I really like. I gave up on using HiVi drivers as they had limited Xmax and high distortion before they reached Xmax. I was initially attracted to them by the ruler flat response in the data sheet. They don't publish distortion figures for a reason. You might look at the Aurasound Whisper 2" instead. They are amazing. Go get a miniDSP digital crossover and you can save a lot of time and get much better results. Go download Visaton free Boxsim software from their website. Enter that design and see the wild variation in the directivity with frequency. It maybe an entertaining speaker, but I don't know anyone saying, let's have wild swings in directivity and then designing a speaker to achieve that.
Great project! Been considering something similar for over 10 years myself, but never get around to it. Was going to encircle a planar driver with some small midbass drivers. I wonder if your measurement labels are incorrect or something btw measurement sweeps got altered. There's no way that the above 7K response ON AXIS should be lower than off axis. And the smoothing of the orange line looks more than the green and blue. In any case, looking forward to further progress.
It is great to see your enthusiasm with these audio projects. You look to be having fun with them.
I promised myself this a few years ago - that I'd gift myself the indulgence of getting back into the hobby after pumping out woodworking content for 10 years on TH-cam.
Too bad that I'm working from a channel that wasn't built on audio projects from the start. Too many subs that aren't watching the new videos when they come out equals no chance of having my videos recommended to the people who would watch them.
You always have the most interesting toys.
I'd like to see some arrangements with AMT's and soft dome upper mids in a 4 way full range.
That is a great idea and looks awesome
Thx! Very exiting to watch.
Best Rgds/Anders
Sweden
How about a MEH? It does nearly the same thing but it's even more of a point source as the speakers are bunched up together. The cancellation from the back wave bouncing from the throat affects ALL distortion above the passband of each driver, which eliminates all harmonics outside of it unlike in a conventional speaker, where each cone plays all it's harmonics. This means that distortion is virtually inaudible except for the lowest harmonics of the lowest tones of each driver (which are not necessarily unpleasant) and the distortion doesn't rise with SPL like it does on drivers on a flat baffle. Also time aligning of the response is nearly constant across ~50* in front of the speaker. Being a horn it doesn't have much output outside of it's beam. It basically behaves like one driver but without any distortion.
Four inexpensive 3" pro audio transducers don't need to look nice, so they cost less. Sensitivity is high because of horn loading. Construction is tricky because of all the trapeze parts and angled but the enclosure is also more stiff thanks to natural bracing of a pyramid horn. The main downside is very wobbly frequency response.
What is a MEH? I only know that word as ‘I’m not impressed’.
@@nathandaniels4823 Multientry horn, like Danley Synergy horn
I was gonna do something similar to that in a Dodge Shadow Turbo... the car never lasted long enough for me to complete the audio ambitions I had for that car. I WAS gonna build out the door panel to basically do the same thing...but in a car.
This is the first video I have watched from this channel. I was very impressed and subscribed before it finished. Some of your explanations on why/ proposed benefits of this design would also apply to the tekton speakers. I’ve watched a bunch of different people including every thing tekton published, and I believe you have explained some things not mentioned before and did it in a easy to follow manner. I look forward to watching more of your stuff and hope it’s all this good.
I had the same idea a while back but with the tectonic 2in bmr... Who knows might try it some day 😅.. think my inspiration came from the xtz cinema speakers that use multiple smaller tweeters to act as a single big one... got me thinking that maybe i could get a near full range experience with a simple design... which was only simple in my head😂😂
The membranes in your concept do move as well alike a typical coax-speaker. The difference? Your set up does not as much work like a waveguide, but there are still cones, alternating sound coming from the tweeter. If a tweeter beams like here, beacause it is a horn loaded dome, this would be the same with the typical Tannoy-Speakers, that use a horn-tweeter in the middle of a huge cone (12" or 15" for example). In this case, the doppler-effect, if hearible (what I doubt) at all, will be minimized.
Siempre es interesante ver tus videos y espero poder ver el proyecto final. Seguro será sorprendente.
I prefer a 12" - 15" woofer in a 3-way speaker cabinet set-up. Add a pr of di-pole tweeters and it's great
Impressive, evtl use speaker to match the sensitivity of the tweeter and try a 6db crossover!
Interesting project, of course I would leave it open baffle, I almost never do any conventional box anymore, haven't for years.
Do you think that these circular speakers arrays can or could ever behave like a very large woofer, maybe like a virtual woofer of the same diameter as the array? My inspiration for this thought is very large array radio telescopes, but in reverse.
Would like to know how you connected the speakers (circuit diagram).
Thanks for sharing.
Good job 🔥🔥🔥🔥💯
Now I’m waiting to see a video with 12 of those woofers surrounding these mids for a true coax design. But where would you get a sheet of plywood that large? I’m sure you could figure it out.
That would be neat :)
Have you seen the danley sound labs PA speakers that basically have this same principle taken to the extreme?
They also measure very well
I wonder if an odd number of mid-range drivers ( like five ) would be better. Five would have less symmetry and thus results in weaker resonance fields both in the far field and in the box.
At least one of the issues with any odd number of drivers (above 1) operating over the same bandwidth would be the net reactive impedance load, which it drops low enough could cause more than a little bit of grief to many amplifiers- hence, I think John’s wiring configuration of two series wired sets of paralleled triplets.
@@fonkenful I did not think about wiring. I guess a series of five with 2 ohms speakers would be hard to find and purchase.
@@gregs7918 Parallel wiring is simpler for most folks to understand and implement, but it can very quickly reduce the net impedance load to dangerously low levels. While I never like to presume the expertise of others, keep in mind that the “rated impedance” of any individual model of moving coil driver is a nominal figure that will vary with frequency, often to well below half the rated figure. It’s that phenomena, along with the complex capacitive and inductive reactance of filter / crossover networks that if not carefully considered can cause conniption fits in amplifiers. Electronics with well designed protection circuits may save themselves, but damage to either the load or driving devices should always be a concern.
In my 20 or so years of DIY speaker building, I never implemented an array of more than 4 drivers of the same type in a design - most commonly as two pairs of small mid-bass units in a bipolar side firing configuration- and as they were generally “8ohm” models, a simple parallel/ series was easily accomplished. It also made for relatively simple modelling of passive crossover networks.
Commercial manufacturers with sufficient order volumes can specify their own proprietary parameters from driver foundries, including higher impedances that would allow for a greater number to be run in parallel.
Of course, if one were to throw enough resources at the design and go fully active with single amp channel per driver, then many of the above noted concerns become moot.
Interesting. I wonder how it would do if the ring of drivers was splayed outward a couple of degrees.
I wonder the same
Biggest difference would be how difficult it would be to do that. The baffle would have to be machined to tilt each driver, yet have them sitting flat to make a good seal. That alone would make it impractical, unless I could be sure that the results would be beneficial.
@@IBuildIt You could do a series of pointed segments with compound angles on the edges. In contrasting woods it would look interesting and seems to be right in your wheelhouse. No idea if it would improve the off axis, but maybe you could mock up a test with some driver wedges to put on your test baffle to see what the results might be. I wonder if simulation software could give a clue? Just an idea based on what you got from your tests.
Too much work for not enough in return. Besides, the off-axis response looks great already.
Im just Curious what is the connection of these speakers? Series Parallel mono? Parallel connection Stereo on one baffle? Please enlighten me a bit Confuse😢 how are these speakers wired and powered, thanks
92 dB on axis at 13k and 84 dB at 20k (Almost half as loud). Looks like another tweeter or two or at least one with more high frequency response is needed. Pretty good from the low end to the mids though. Cool looking design.
That's the typical drop-off you get from horn loading a tweeter. Since I can't hear above 11k anyway (and there's not much musical content up there either), it's not something that needs fixing.
@@IBuildIt I am fortunate enough to still hear to 17,500 Hz in one ear, and 17,000 Hz in the other ear. So yeah, high frequencies that roll off before that sound like listening to music with a pillow over my head. LOL. But hey, if 20-11,000 Hz is good for you, more power to you.
I've got an old Energy Center Channel with a tweeter and two mids flanking it diagonally and back in the day when the experts tested it, apparently it had almost no change from on axis to off axis, (or so wide that it wouldn't be an issue in standard application). I wonder if two mids would work as good, or better than 4, or 6? Lots of the vintage speakers employed two mids.
Love the videos!
Thanks! I need the extra drivers to push up the sensitivity to match the tweeter. Using just two would mean I'd have to pad the tweeter down a good 12-15db.
@@IBuildIt lol... That's right you mentioned that in the video and I sort of forgot it thinking about the possibilities of the general arrangements. Maybe a less efficient tweeter or more efficient mids. Interesting experiments and I'm interested to see how it goes. I've seen some super high end boutique speakers in videos that look like that. The one thing that I don't understand, is that usually the Mid-Range is hotter than everything else and our ears are more inclined to be more sensitive in that range, so I'm not clear on why more Midrange is better, or how it's not negatively impacted by comb filtering and cancellation. I've got a couple old Jensen projects coming up that have the dual mids, spread far apart and at different heights with the tweeter sort of centered and nested in-between, but up a little higher... Pretty sure I'm going to use pro drivers for one or both projects. I was considering using one of the holes for a port, but it would throw off the cool retro look.
John they look great! 🙂what is the sensitivity you get with the mids arrangement like you did parallel and series? they are 81 db each only..
Great!!! ... soundtest pleaseeee!!!
I think you should take a look at the Reckhorn C-191
I wounder why there is No combfiltering on the multiple speakers made in the 70-80s with 3+tweeters on the same crossover???
Donald North Audio has a better/moreover fully realized version of this that further considers the baffle edges and also has an open baffle woofer section
Great idea. Maybe the 3" dome mids would be even better for this application. Also do you think non horn/waveguide loaded tweeters won't work? As the dispersion would be too wide & interfere with the cones?
Hi John, great information for the DIY but is it any different than the array used in Tekton speakers?
Yes - Tekton uses identical drivers.
Looks kool
I've built speaker boxes, but never had the equipment or know how to tune them. Do you have any recommendations on where to get started on how to learn those things? Thank you.
How come you don't use things like desidamp to improve the sound quality? It's brilliant, especially used as a sandwich of thin layers of canceling the rebounded sound effecting the end result at all.
Very cool experiment: Point source, high efficiency, and good power handling.
What happens with a small delay to outer drivers to make a spherical wavefront (like Quad used to do with the ESL 63)? Or perhaps better, if drivers are actually on a hemisphere? With your woodworking skills this could be visually stunning.
Very surprising lack of cancellation when off-axis horizontally. I wonder if the three vertical pairs formed by your particular array serve to suppress some of it.
So, basically Tekton open baffle speakers
What would one call it. Hexagonal coaxial?
If you look at Augspurger specs, they do a 5" 16 ohm 500Hz - 20K Hz horn over an 8ohm 10 or 12" mid bass for 200 - 500hz, then a 4 ohm 12 or 15" sub for 20 - 2 or 300Hz. With an awesome DSP set up. Roughly. I highly recommend looking into these. They are current recording studio standard. Amazing what they do with EQ and phase issues. I learned a lot from these guys.
when do we hear it?
People largely rubbish this kind of thing, but as long as spacing to wavelength is within spec it's actually really a good design, like yours, and the measurements are telling you such.👍🙂
Are those M4N's?
Ah, just looked in description, M3N. Those HiVi driver's are really a steal. The M8N is really good for bass.
fun!
How about getting the mids closer to tweeter and slight angulation of mids 15 degrees
Off axis and on axis plots don't seem to correlate with each other very well. If they are, then you don't have any interferences and diffraction. You most likely have a good amount of destructive interference going on... but again, once you get to a serious point, these issues could be resolved. Congratulations!
Tekton does this
Nope.
Here is an Idea Id like to see you try with this: Have a unique crossover for each of these midrange drivers... separating them, so that Each driver only gets a fraction of the total Midrange spectrum. Why? When you play music that has a lot of different instruments and vocals all playing at the same time... the drivers will often end up suffering some Distortions.. as it cant easily keep up with how much demand is being placed upon it (especially low strength drivers). But when you split the workload up... there is far less chance of any distortions taking place. Each driver will than be MUCH cleaner and defined, with Far less potential for ANY distortions at all.
I actually realized this issue, when I was using my Pioneer surround sound amp. I normally only ran it in 4 channel mode... but when I tested the center channel.. I found that the left and right speakers were playing the movies music... so much cleaner and clearer. That was because most of the vocals were being shifted to the center channel... taking some of the Burdon off of the other speakers.
It would also be good to put in at least two woofers, and do the same thing with them. Half the frequency ranges for each of them, so that they both have less workload, and thus, much less potential for distortions.
Im guessing you will use Open Baffle for the woofers.. but if closed.. Try putting in Passive Radiators on three sides of the cabinet (Left, Rear, and Right).
As for Midranges... Im sure those are decent... but the best Midranges Ive ever heard, were 3 inch Domes.
And it would be fantastic if you tried EPI Inverted Tweeters, from the Humanspeakers website. Ive never experienced a Wider Soundstage, by any other tweeter.
I'm thinking it may be interesting to run a test where the top three mids cover the upper midrange, say from 900Hz to 1800Hz, then have the lower three cover the range from 300Hz to 900Hz.
But this idea that the music is complex is mostly a misconception of what's going on. The speakers respond to a single electrical signal, as in if you slice it at a single point you will get a single voltage.
The way we perceive music is that several difference frequencies are playing at once, and while that is true, the signal that results from that is still just a series of different voltages that drive the speakers. Those multiple frequencies get translated to the language the speaker needs to produce sound - a range of voltages.
@@IBuildIt Nice to hear that you may try this.
Of course the Music is Voltages... but.. its still a bit more complex than that. Those voltages are then translated into Mechanical Movement... and this is where the Distortions can come into play.
If there is a single frequency being represented... that is very easy for a speaker to replicate... as its just a simple vibrational pattern / wave.
But where multiples frequencies are happening all at once... there can be limits as to how well the drivers can mechanically duplicate all of them, faithfully... all at the same time.
Obviously, the strength of the magnetic forces are a big factor... as if the driver cant accelerate fast enough to keep up with the signals changes... they will be some degree of loss in the expelled sound.
This is why higher end Drivers, cost much more... even while they appear to have the same frequency output capabilities. The use of larger and stronger magnets... special "stronger but lighter" cone materials, higher precision tolerances.. such as less spacing between the coil and the magnet gap, and some other factors that Im likely not even aware of.
Higher frequency drivers seem to suffer less from distortions than woofers... due to a much smaller cone size / mass. But... they also are handling a LOT more of the complex workloads... and at much higher rates of speeds... so any tiny amount of distortion, will be quite impactful.
Anyways... I have a Theory that Bose was doing this Split Frequency method, OR is quickly alternating the signal between two or more drivers. In this way, they are still greatly reducing the overall workload demands on each single driver... and the switching would be fast enough, that nobody would audibly be able to Hear the alternating switching between each driver.
Actually... This was somewhat similar to how the original surround sound amps functioned. Every Nth of a second... they would take part of the audio signal... and throw it to the rear speakers.
In fact, you might also consider trying both methods at the same time. Where you split the frequency demands between a pair of drivers.. AND you alternate between two or more different Pairs of drivers. Obviously, this would be a lot more complex to build the required electronics, to accomplish.
Anyway... this is one of the reasons why I dont care for mere "Sweep" data... because a lot of speakers can replicate a simple singular sweep of frequency changes, without any Distortions. Its when you are playing very complex frequencies all at the same time... and at maximum volume levels... where the distortions will end up being noticed.
I dont know how they Measure Distortion levels in speakers / headphones... But I would imagine that you would actually need to play some complex music through them, at loud volume levels... and analyze the Entire music track, compared against the original signals. The changes might be very small on a graph, and so there must be some sort of automatic computerized analyzation routine, that figures out the exact percentage of distortion issues. (of course.. your ears will often easily be able to hear muddying of certain sounds)
How are these wired? Final ohm load? Nice
WOW, it looks like a Virus🦠
Okay so probably a very stupid question but i have been geting very mixed messaging from the articals i read.
Can you make a open baffle speaker with a speaker made as a in wall infinite baffle. Like are the speaker units essentially the same and its just the design of the housing thats the difference or do you have to get speakers more made for this set up.
Essentially, any loudspeaker can be implemented open baffle.
The array configuration resembles a Tekton speaker except for it being open baffle
I want to do this with 8 or 9 per side, full range drivers without the tweeter as an open baffle. Time and money limited...
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*Sees cost of this arrangement
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Hi, I tough the 3 db rule applied to the doubling of drivers, 1=85 db, 2=88db, 4=91 db, 8=94 db and so on...
So did I and maybe I'll see that much gain when the drivers are in a cabinet, rather than on an open baffle.
I built a pair with 9 small cheap drivers on each side.
They don't sound good at all.
May be the drivers or that the guesswork box i built.
Curious about your cross-over. Is that a second-order filter?
The drivers are too big and the spacing is too far apart, try 5.25" drivers or smaller and get them as close as possible to reduce the cancelling. This idea solves some issues but creates others. Very powerful however.
Tekkton
Tekton speakers Aldo the DNA speakers same concept
DIY Tekton Audio? 🙂
Science inventing. 0:43
Can you test outdoors to remove any room effect?
The measurements are gated, which effectively removes the room interaction.
Cool, thanks.