I say "dead simple" and that's true - it doesn't take much to glue a weight onto a speaker cone. But there is a lot of work that goes into figuring out how much weight to add. And what that weight will do and whether it's worth the tradeoff. All of this will be old news to more seasoned speaker builders; there's nothing new about this method. But since I considered doing it for the four woofers I have, I thought I'd make a quick video explaining it. The added mass lowers the Fs (resonant frequency of the woofer) but also make it harder to drive. You need more power to get the same level of output (spl). Also, if the woofer doesn't have a long enough stroke (Xmax), it may not be suitable for this at all. The lower the woofer plays, the longer the stroke needs to be to avoid audible distortion or damage. In the end I decided to use the woofers as designed after a break-in period that loosened up the suspension. New drivers (even ones that are 10 years old...) will loosen up over time from being used, and that break-in speeds that up so that you can get more reliable test data. The speakers I'm building will be in two section - a subwoofer on the bottom with three-way speaker on top. The subwoofer will have two of these woofers in each box in an isobaric arrangement. The chief advantage that isobaric gives you is that it cuts the size of the box in half. It really only makes sense to do it when you have a situation like I have where I have 4 woofers that can be used.
Cheers for the reveal so early in the video. First thing I thought of, was not only the sensitivity would decrease, but so would the damping factor. Naturally you can control some of that with more power, to an extent, but if the voicecoil / magnet / motor assembly isn’t up to it, it will sound floppy Back last century when I would rebuild JBL PA drivers and give them an extra kick, I would not only add a little bit of mass to the cone, I replaced the voice coil with a longer, edge wound coil to give you more even energy over the travel of the cone. While you had to have an amp with a decent damping factor, and while you could drive the cones past their point of linearity, these speakers thundered. You didn’t need to drive them as hard, but, you did need an amplifier that was capable at driving them hard. Garry Nessel taught me this trick. Brilliant guy. Sadly he is no longer with us.
Very good clarification there; and that's why I would never attempt this on a high end subwoofer that's had tons of engineering behind it like my Sunfire or my Martin Logan. I'm curious to try it on a cheap one though just to sate my curiosity.
I built my own speakers over 30 years ago, listening to you describing the technology behind it is music to my ears, I was eyeballing it all the way back then, building crossovers with my own copper circuits, building constriction chamber channeling with plywood to give my bass reflex speakers the resistance needed to produce a deep and rich sound. I painted mine black with Tremclad mat black metal paint because it was all I had available. I exchanged them to a girl for some Tanoy classic 18 inches that I never loved as much as my own. Exchanged those for some System Audio much smaller ones over 15 years ago. Watching you do all this research is waking back all these memories and makes me wanna build some speakers even if I don’t need them nor have room for them:)
I feel you fellow Audio nut😊 I'm obsessed with quality vintage Audio specifically early to mid 70's and im a Goodmans fan because they where the industry leader for nearly 100 yrs now and I've got some magnum sl 12 inch which are beautiful to look at atvthem off the ground by 15 inch or so and isolated really rattle the windows and the cones are fast and the crossovers are gone through and point to point and even the original xovers that I still have are amazing tech and sound epic and the preceded the magnum k2 which have moor bracing inside and a 18 mm divider board that seporates the mids and high drivers act like a subwoofers loading chamber because if I remove the midi get down to 40 hz and it hurts my ears and if I move the tweeter and use a 20binch stiff cardboard tube as a port they go way below 12 hz and make me feel sick but the point being the cab being better braced even having a hiyer fs sub still the same just less spider stiffness ect and ut improves the sound byso much and the are 97 per meter and that's 91 by today's standards and I've got 4 sl and two k2 and a pair of the original Goodmans Achromat 400 prototypes and they are pure studio monitors and nit like the clear plastic subs that followed in the akro's and beta but they have 3 inch dome midrange and long throw 10 inch subs and the fact they have not skimt on tech and materials they are just such and awesome speaker to intensive to they are so fat it's unreal how perfect they are and ivebgit a 12 g pair of ATC monitors and they are on par with but I supose at the time they would of been a similar price range a d the only way that I could come close to high end was to build myself using what I had learned by falling in love with my British auto monitors and big floor standers. Big as fridge lol not guide but the sls are hefty. I love it and I think that their is nothing more wholesome and rewarding than listening to some flac lossless of cd even and having tears apear knowing its just perfect to ear.. build some more you won't regret ut.. well you allready know that bit. Later bud.😊
Get some good 5" FR drivers and run them open, on top of floor standing boxes and with a woofer in the boxes. Slit the FR cone with a razer blade (right through) few times around, close to the center (to extend highs like crazy). The best, most holographic speakers in the world! 😅
I'm glad you mentioned the trade-off right away, because you very rarely get something for nothing. Needing more power to drive a heavier cone also means that that may be putting the voice-coil at risk of heating up and burning through. Speaker construction and audio are fascinating subjects. I found your video interesting and entertaining 😊
Quite a few years ago we had the traveling Sesame Street show on our stage. They used a Bag End system that boasted a sub woofer that would go as low as 8 hertz. You can’t hear that low, but you can feel it in your chest. Amazing output for the compact size.
It may change and lower the frequency response of the speaker, but as mentioned , decrease the sensitivity and worse of all increase the inertia of the cone, resulting in slow flabby bass, and more distortion! Have fun if this is the right cup of tea.
My dad built a few dozen "W" bins for a Neil Young concert on my island in the late 80's. They were "extra weighted" 18 inch dual drivers in a standard W bin. The extra weight was lead solder and liquid nails. He had the budget to experiment. I think they performed well. BTW: way cheaper to build 'em than buy 'em where we are.
You got me on the thumbnail, but still enjoyable and keen to see the build. I just bought some monitor audio speakers, I like the sound the make but want a better sub woofer than wwwhat I currently have.
I have almost no interest in actually building speakers or anything like that, but this content is just so damn interesting. It’s fun to watch someone really nerd out on this stuff and learn about the engineering that goes into making a speaker.
He knows what he'll have after. Wild basic guess $10.000 -/+ speakers. I love this way of thinking. At the end a new skill and nice wood working shop etc. IMHO outweighs working overtime and saving
Don’t start building speakers. It’s a wormhole that has no bottom. Everything you create will fall short of perfection which begets the next project and so on.
@@6-Iron oh man, no truer words can be spoken. I’m going from spl type bass in my truck to sq. I have all new gear and it’s like reading chinese getting set properly. One minute it sounds amazing, play different music and oof! Tuning definitely takes some patience but man it’s so much fun to play with audio.
In effect its not so much dropping the bass response to lower frequencies, but really lowering the sensitivity of the speaker at higher frequencies. In effect basically like dropping the mid-bass bands on an EQ. The extra mass lowers the cone excursion at higher frequencies since the motor force is not changing despite the extra added mass. Can be useful to a speaker builder if your trying to optimize multiple parameters at the same time, but worth saying that its not something you'd want to do to a set of off-the-shelf speakers since it would throw the balance off, unless you plan to retune or redo the cross-over.
Its been over 20yrs since i was into audio but jeez from what i recall ever reading was that a great bass driver needed to have as light and stiff a cone as possible. the magnet and voicecoil would be ideally nice and large but i dont recall ever reading that adding weight to a driver cone would make it better just the contrary. was that completely wrong? I find this channel fascinating as its rekindled that interest from my college days. loving where this is going John...
I didn't say "better", I said lower in frequency. A light, stiff cone is always better for transients, but less so for anything playing lower than 100Hz.
Appr3ciate the knowledge. Im more of a new speaker builder. I have 15 years experi3nce. I have made over 15 portable bluetooth speaker enclosur3s with drivers and amplifiers and more recently higher voltage amps requiring 36 volts. Thanks for the video, i used what you said on a couple passive radiators to add mass...
Interesting. I can see the excursion being tested more often after adding mass alone. All the same this is a theory I will likely test. Thankyou for sharing
It's not a dead sinple trick when you change all of the speaker specs and a normal person does not have the equipment to get those new specs to be able to create a correctly tuned enclosure. But, your click bait worked as it got me to watch the video. Great work. Hahaha.
Sony had a tech similar to this in their Maximum Television speakers. I had received a pair of well used Max Tv speakers as partial payment for a job I did for a lady. They actually sounded really good (especially for free) and used them for years. I think the woofers were called Super Acoustically Loaded, or something like that. Being curious and armed with implements of disassembly, I set out to see what a super woofer looked like. Well, strangely enough, they looked like any other high excursion driver... except the dust cover had a weight attached to it. At this point, I cannot remember what the weight was made of but, for the size of the driver (6.5" IIRC) they had the ability to shake the floor of my apartment.... much to the chagrin of my neighbors. Mystery solved, put them back together and continued to enjoy them till they got hit by a surge from a lightning strike.
As I am an Old School Engineer I only claim a speaker is a Subwoofer if it is designed for frequencies below 30 to roughly 10 htz. Lol I play Bass guitar and mine plays down to 15 htz very nicely and can flap my pantlegs if I am standing in front of the speaker assembly. Keep up the good Isobaric information since people are generally ignorant about that type of speaker.
@@jacobclark89 I Have used audio generators to drive my Ampeg SVT PRO 4 amp into my discontinued model Bass Speaker Cab that has 4x10inch speakers and 3 ports that the spec says goes to about 28 htz. With 2400 watts and equalization it plays down to 7.5 htz but it takes a lot more power. I normally only play down to 15 Htz on the Bass Guitar in special situations for special effects. Lol
Nice experiment! JBL were masters at this... they added a 35g mass ring to the 2235 woofer, or left it out on the 2234. Various JBL woofers were paper but with sprayed on material to add weight and damping.
Ambitious project, very much looking forward for the result. I assume this is going to be at least a partialliy active design? With a separate amplifier and active filtering for the subwoofers? Passive filtering at 80 Hertz isn't something you really want to do. One more thing regarding the isobaric enclosure: Try to keep the amount of air between the two drivers as low as possible. You want a stiff coupling here.
The eventual plan is full active, for the three-way as well as the sub, but for now the subs will be driven from the subwoofer output from my 2.1 receiver with the crossover set to 80Hz.
I decided to add mass by cutting a black piezo wire short enough to go around the outside edge of the dust cap on the active subwoofer in my guitar rig since it was already overdriven with a decent bass knob and power amp going through a stereo pedal. sounds perfect with a slightly deeper voice. It really brings out a layer of sub bass when you need it.
Ya, I’m getting into speaker building and yup everything is a trade of. No such thing as the perfect woofer just perfect for the needed application. Though I do collect old infinity perfect woofers.
What you suggest would basically allow the amp to increase output in the desired frequency range. The only way i can see weights increasing subwoofer output is by increasing excursion, because it isn't increasing cone surface area. Adding weight to a woofer seems like it would reduce efficiency and frequency response, and inhibit its' ability to hit higher frequencies. In my opinion, stay within specification. Don't modify your subs or add weights to increase excursion. If you want more bass, get bigger subs with higher excursion, more surface area, and stronger (bigger) magnets. Then get a stronger amp to match.
Doing this is fine if you arent looking for max output, but what this is essentially doing is lowering the max output capability of the driver. You aren't actually getting more low end. The max low end of a driver is excursion limited, so that doesn't change based on the fs of the driver, however, the max output of midbass and high frequencies are power limited generally. This also means they are sensitivity limited. The era of full-range speakers is ending and for good reason, subwoofers can be placed in better modal areas and can do much more than most full-range speakers. IMO it is never a good idea to intentionally add mass to a driver to get lower bass, you are better off using DSP to eq up the low bass because you'll still have the headroom in the midbass and higher frequencies. You can also tame peaks and modes to get much better sound quality.
Interesting, but I would advise against this is you have other means. Lowering the Fq does not really mean you get more bass. If you need a boost down low, then you can do the same with EQ instead of making the driver have a higher Qts and effectively lowering it's sensitivity. It will have to consume more power to deliver the SPL across it's whole passband esp. If it's a lot more mass The most high end subwoofers typically have huge motors compared to their moving mass and low Qts. Mass is the enemy! Final Fq is really defined by the system, not just the driver. In short if you need more low end, pick a different box or EQ to driver if you need to
This might be a year old, but I just made a similar comment. I commend him for trying to think outside the box and post it on TH-cam, but I don't think this guy actually knows much about speakers. I wonder what his background is since he seems to misunderstand some very basic engineering principles in a few of his videos.
Did you find that your break-in period lowered the f3 at all? I've read that long (24 hours) burn-ins can gain an extra ~5db or so of lowered fs/f3. Very cool cabinet design.
There was a significant change after the first hour, Fs went down from 30Hz to 28Hz. But the second hour of break-in changed very little, so I don't see a need to go for much longer than 2 hours.
I believe that because ,I had a pair of design acoustic speaker ,and the woofer had three piece of rectangular wood in it. and the base of that was unbelievable .to this day I haven't heard no bass like it
I used BBs for years glued around the dust cap with white glue to achieve a lower resonance. It is not a solution for all woofers but I have used for drivers as small as 4".
I have built speakers and have poured through the speaker and vent hole floor-leveler cement to a thickness of about 5/8” for dampener. They sound good but I don’t have the equipment to test like you do, so I was wondering if you would do it. Obviously you have to pour in cycles since there are six sides. I got three side pours in a single day.
Looking forward to this build. Nice looking speaker design for sure John. Keep up the great work! Can't wait to see how you finish them. I was thinking a nice veneer on the front panel and alternating w/ flat or gloss black for the triangular facet and then another wood veneer facet as you go around the sides and back. Really cool looking design. So wish we could hear them, I'm sure they will be awesome.
Fascinating John and a subject I really enjoy being a Hi-Fi nut. Given there are difference shapes of enclosures in manufactured speakers, I'm guessing this *shaping* is important as well as the sizing ?
i used 2 car audio subs, a crown 1502 to power them, and made my own 3-way speakers with parts from partsexpress... It sounds way better than any store bought stuff i have owned in the past =) All sealed boxs.
Haha! I added mass to coax 6x9s by cutting off the tweeters & gluing on dust caps (castrol 1qt bottle caps w/ superglue 😂). i did that years ago, in my car, & it still works fine.
Pardon my ignorance on speaker basics - would like a tiny direction for my problem. I bought a 8inch 50 watt woofer (not sub woofer) about 15 years back, used it for few hours and it sounded good. I opened it today and connected it to my amplifier and it outputs too little volume. I gently pushed the cone and spider up, and the volume goes up and it vibrates well. How can I fix it? The spider feels hard... the soft rubber on the outer edge of the cone is soft/flexible...
For the first seconds, I knew what you were going to do. So, if I do that with a woofer and a Passive radiator, I can go lower? (I might blow the speaker lol)
I just got a new subwoofer from Bestisan and it's a downfiring version. I also have it in a side firing version. Both have the same amp and woofer. Only thing is the downfiring one has one small rubber pad stuck on the dust cap off axist. Is that a mass pad of sort or was this a repair? I'm stumped cause it's new out of the box and I've never seen this before. 🤔
great vid, yea the tittle is a very good magnet... what software is that. I also do my own speakers boxes, if you can help me i want to make some new boxes for 4 15s inche woofers. I want a punchy bass that would be feel on you chest than a bass that make everything rattle, i want to keep these compact and light. since ill be using these in my lil gigs...
would it be possible to do something like this to a commercial speaker after taking it apart? I bought a beosound explore but the bass is zero even with app fine tuning.. and looking to add little bit of bass to it
Fascinating. I'm kind of surprised I've never heard of the isobaric configuration before. I'll have to go look into the physics and benefits of using it are. If I had to guess off the top of my head (and as you elude to in the video), it sort of simulates a larger enclosure volume? Almost like a port, but... active? I'm probably way off.
These are not active design. These are passive design. John will be using passive crossovers to regulate where each signal will be going to,ie: sub,bass,mid,treble. Active, uses a active crossover that is adjustable,electronic circuitry. Put that straight into the amp,straight to the speakers.
I built very similar set of speakers. Use Emmence drivers in an Isobaric arrangement in a sealed box with a 15 driver upper section. When used for two channel listening the bass is punchy and clean. In theater use I have numerous additional subwoofer.
This technique was used years ago by Kenwood . On the drone cone I believe. The system was supplied with a couple of screw on weights. Breaking in .... Guitar strings are the same. A new set tend to have a jangling sound then settle in and become sweet then latter sound dead.
Same thing really. Acoustic efficiency might go from 2.5% to 2%, while sensitivity might go from 92 dB/W/m to 89... or something like that. They’re the same thing but using different units.
For the ever so slight increase in the bottom octaves, it looks to take too much of a hit along the rest of the frequency curve, however, it would be more useful if it better balances the overall output of a speaker at a given power applied. Wouldn't changing the crossover do the same?
I am interested in these metal rings to add the mass to a woofer. Whered you get that? I have some 18s with an fs of 32 and i like it more like 28 or 26 hz. SO can i add a ring to my woofer like this to achieve the fs i want?
Question: I just received a Yamaha soundbar and a SHU sub... I tried hooking it up to my bedroom TV (Sony A9S Oled 48"), The light's are on on the Sub, I have the sub connected to the Soundbar but there's no sound from the sub. The soundbar plays but not the sub. Suggestions? Thank you Joe
That's the secret to the under-seat subwoofers. I have a Blaupunkt powered subwoofer and the center cap came unglued, making a horrible amount of racket. When I removed the cap, I found it is made of a heavy piece of metal. Adding weight to a speaker slows the cone down. It's like a mechanical crossover. It doesn't make it hit the lows harder; it simply rolls off the higher frequencies.
how much weight can be addedd? If i model stuff on winISD it seems like the more the better when it comes to bass, how do i evaluate the power trade off?
In love with the angles of the tower/boxes. I have skinny towers compared to the width in your design. The double woofer stacked weirds me out. Never seen it before but very interested in how it really adds up with the math for power.
I found a 1000 watt active PA speaker with a 12” woofer and I’m looking to replace the woofer with the deepest subwoofer I can find. Any suggestions? Am I crazy?
I’m new to sound systems and i would like some deeper bass out of my sub, it’s a jbl powerbass 10, how would I know how much weight to add. It’s a good thing I saw this post as I was gonna go and just randomly throw on 14 grams
In these days, adding mass intentionally means something between not having tools, not having options, not having the right speaker or not having the right design. But one still can encounter such situation. At that moment, it is a good lesson.
Could you expect to see the same 9 fs drop for any woofer by adding 14g to it, or is it more of a specific to each application? I use subs in car audio and was wondering if this would work the same.
With all else staying constant on the woofer, how does it play any lower? Yes, the F3 is lower, but that doesn't mean anything since the xmax and the motor BL is still exactly the same. Even the screenshot of your F3 and the frequency response shows exactly what I'm saying. Sure the F3 dropped, but that's because you lost like 3db above 35Hz. That doesn't mean you gained anything below 35Hz. If you want to change the frequency response, you could easily do that with a DSP, no need to add mass. How does adding mass boost the SPL of the lower frequencies? I feel like I'm missing something.
I say "dead simple" and that's true - it doesn't take much to glue a weight onto a speaker cone. But there is a lot of work that goes into figuring out how much weight to add. And what that weight will do and whether it's worth the tradeoff.
All of this will be old news to more seasoned speaker builders; there's nothing new about this method. But since I considered doing it for the four woofers I have, I thought I'd make a quick video explaining it.
The added mass lowers the Fs (resonant frequency of the woofer) but also make it harder to drive. You need more power to get the same level of output (spl). Also, if the woofer doesn't have a long enough stroke (Xmax), it may not be suitable for this at all. The lower the woofer plays, the longer the stroke needs to be to avoid audible distortion or damage.
In the end I decided to use the woofers as designed after a break-in period that loosened up the suspension. New drivers (even ones that are 10 years old...) will loosen up over time from being used, and that break-in speeds that up so that you can get more reliable test data.
The speakers I'm building will be in two section - a subwoofer on the bottom with three-way speaker on top. The subwoofer will have two of these woofers in each box in an isobaric arrangement. The chief advantage that isobaric gives you is that it cuts the size of the box in half. It really only makes sense to do it when you have a situation like I have where I have 4 woofers that can be used.
Cheers for the reveal so early in the video. First thing I thought of, was not only the sensitivity would decrease, but so would the damping factor. Naturally you can control some of that with more power, to an extent, but if the voicecoil / magnet / motor assembly isn’t up to it, it will sound floppy
Back last century when I would rebuild JBL PA drivers and give them an extra kick, I would not only add a little bit of mass to the cone, I replaced the voice coil with a longer, edge wound coil to give you more even energy over the travel of the cone.
While you had to have an amp with a decent damping factor, and while you could drive the cones past their point of linearity, these speakers thundered. You didn’t need to drive them as hard, but, you did need an amplifier that was capable at driving them hard.
Garry Nessel taught me this trick. Brilliant guy. Sadly he is no longer with us.
Very good clarification there; and that's why I would never attempt this on a high end subwoofer that's had tons of engineering behind it like my Sunfire or my Martin Logan. I'm curious to try it on a cheap one though just to sate my curiosity.
⁰
Waiting for your tests and measures for this method!
it's very sus when you don't do a before and after demo /tone test, i am very skeptical and don't wish to damage my speakers trying this
I built my own speakers over 30 years ago, listening to you describing the technology behind it is music to my ears, I was eyeballing it all the way back then, building crossovers with my own copper circuits, building constriction chamber channeling with plywood to give my bass reflex speakers the resistance needed to produce a deep and rich sound. I painted mine black with Tremclad mat black metal paint because it was all I had available. I exchanged them to a girl for some Tanoy classic 18 inches that I never loved as much as my own. Exchanged those for some System Audio much smaller ones over 15 years ago. Watching you do all this research is waking back all these memories and makes me wanna build some speakers even if I don’t need them nor have room for them:)
@Mac Nifty 😆
@Mac Nifty
Can you tell me of any night clubs in the Atlanta area ' where a fellow can sling around a few $$$ and pick up some nice ladies ?
@Mac Nifty you sure you turned your life around? I thought I saw you on the dark web the other day offering your hacking services..... 🤣🤣🤣
I feel you fellow Audio nut😊 I'm obsessed with quality vintage Audio specifically early to mid 70's and im a Goodmans fan because they where the industry leader for nearly 100 yrs now and I've got some magnum sl 12 inch which are beautiful to look at atvthem off the ground by 15 inch or so and isolated really rattle the windows and the cones are fast and the crossovers are gone through and point to point and even the original xovers that I still have are amazing tech and sound epic and the preceded the magnum k2 which have moor bracing inside and a 18 mm divider board that seporates the mids and high drivers act like a subwoofers loading chamber because if I remove the midi get down to 40 hz and it hurts my ears and if I move the tweeter and use a 20binch stiff cardboard tube as a port they go way below 12 hz and make me feel sick but the point being the cab being better braced even having a hiyer fs sub still the same just less spider stiffness ect and ut improves the sound byso much and the are 97 per meter and that's 91 by today's standards and I've got 4 sl and two k2 and a pair of the original Goodmans Achromat 400 prototypes and they are pure studio monitors and nit like the clear plastic subs that followed in the akro's and beta but they have 3 inch dome midrange and long throw 10 inch subs and the fact they have not skimt on tech and materials they are just such and awesome speaker to intensive to they are so fat it's unreal how perfect they are and ivebgit a 12 g pair of ATC monitors and they are on par with but I supose at the time they would of been a similar price range a d the only way that I could come close to high end was to build myself using what I had learned by falling in love with my British auto monitors and big floor standers. Big as fridge lol not guide but the sls are hefty. I love it and I think that their is nothing more wholesome and rewarding than listening to some flac lossless of cd even and having tears apear knowing its just perfect to ear.. build some more you won't regret ut.. well you allready know that bit. Later bud.😊
Get some good 5" FR drivers and run them open, on top of floor standing boxes and with a woofer in the boxes. Slit the FR cone with a razer blade (right through) few times around, close to the center (to extend highs like crazy). The best, most holographic speakers in the world! 😅
I'm glad you mentioned the trade-off right away, because you very rarely get something for nothing. Needing more power to drive a heavier cone also means that that may be putting the voice-coil at risk of heating up and burning through. Speaker construction and audio are fascinating subjects. I found your video interesting and entertaining 😊
Thanks for the lesson on speakers! Looking forward for the rest of the videos.
The Focus Master; critical. Increasingly lengthy burn-ins;
new facts of life. Thanks for the vid and your work.
Love this stuff, I got into it quite a bit back in the day, but not to nearly the degree you obviously did. I've always found this stuff fascinating.
I can't recall seeing a speaker design like that before. This should be interesting and educational.
Quite a few years ago we had the traveling Sesame Street show on our stage. They used a Bag End system that boasted a sub woofer that would go as low as 8 hertz. You can’t hear that low, but you can feel it in your chest. Amazing output for the compact size.
Bag end are awesome good
Agreed!
Lowers Fs (resonant frequency), raises Qts (and therefore Qtc in closed acoustic suspension system, and misaligns vented systems) and Vas.
Doesn't misalign a vented system if you design your enclosure around your new response 😉
It may change and lower the frequency response of the speaker, but as mentioned , decrease the sensitivity and worse of all increase the inertia of the cone, resulting in slow flabby bass, and more distortion! Have fun if this is the right cup of tea.
My dad built a few dozen "W" bins for a Neil Young concert on my island in the late 80's. They were "extra weighted" 18 inch dual drivers in a standard W bin. The extra weight was lead solder and liquid nails. He had the budget to experiment. I think they performed well. BTW: way cheaper to build 'em than buy 'em where we are.
You got me on the thumbnail, but still enjoyable and keen to see the build. I just bought some monitor audio speakers, I like the sound the make but want a better sub woofer than wwwhat I currently have.
I have almost no interest in actually building speakers or anything like that, but this content is just so damn interesting. It’s fun to watch someone really nerd out on this stuff and learn about the engineering that goes into making a speaker.
He knows what he'll have after. Wild basic guess $10.000 -/+ speakers.
I love this way of thinking. At the end a new skill and nice wood working shop etc. IMHO outweighs working overtime and saving
Don’t start building speakers. It’s a wormhole that has no bottom. Everything you create will fall short of perfection which begets the next project and so on.
@@6-Iron oh man, no truer words can be spoken. I’m going from spl type bass in my truck to sq. I have all new gear and it’s like reading chinese getting set properly. One minute it sounds amazing, play different music and oof! Tuning definitely takes some patience but man it’s so much fun to play with audio.
In effect its not so much dropping the bass response to lower frequencies, but really lowering the sensitivity of the speaker at higher frequencies. In effect basically like dropping the mid-bass bands on an EQ. The extra mass lowers the cone excursion at higher frequencies since the motor force is not changing despite the extra added mass. Can be useful to a speaker builder if your trying to optimize multiple parameters at the same time, but worth saying that its not something you'd want to do to a set of off-the-shelf speakers since it would throw the balance off, unless you plan to retune or redo the cross-over.
Its been over 20yrs since i was into audio but jeez from what i recall ever reading was that a great bass driver needed to have as light and stiff a cone as possible. the magnet and voicecoil would be ideally nice and large but i dont recall ever reading that adding weight to a driver cone would make it better just the contrary. was that completely wrong?
I find this channel fascinating as its rekindled that interest from my college days. loving where this is going John...
I didn't say "better", I said lower in frequency. A light, stiff cone is always better for transients, but less so for anything playing lower than 100Hz.
@@IBuildIt makes sense cheers mate.
Appr3ciate the knowledge. Im more of a new speaker builder. I have 15 years experi3nce. I have made over 15 portable bluetooth speaker enclosur3s with drivers and amplifiers and more recently higher voltage amps requiring 36 volts. Thanks for the video, i used what you said on a couple passive radiators to add mass...
Interesting. I can see the excursion being tested more often after adding mass alone. All the same this is a theory I will likely test. Thankyou for sharing
I love the experiment! Have you ever added more magnetic properties to a woofer?
This helps make more sense of all of the Thiele-Small parameters.
Interesting topic. Looking forward to seeing this series and learning from it.
It's not a dead sinple trick when you change all of the speaker specs and a normal person does not have the equipment to get those new specs to be able to create a correctly tuned enclosure.
But, your click bait worked as it got me to watch the video. Great work. Hahaha.
Sony had a tech similar to this in their Maximum Television speakers. I had received a pair of well used Max Tv speakers as partial payment for a job I did for a lady. They actually sounded really good (especially for free) and used them for years. I think the woofers were called Super Acoustically Loaded, or something like that. Being curious and armed with implements of disassembly, I set out to see what a super woofer looked like. Well, strangely enough, they looked like any other high excursion driver... except the dust cover had a weight attached to it. At this point, I cannot remember what the weight was made of but, for the size of the driver (6.5" IIRC) they had the ability to shake the floor of my apartment.... much to the chagrin of my neighbors. Mystery solved, put them back together and continued to enjoy them till they got hit by a surge from a lightning strike.
The design looks great 👍
As I am an Old School Engineer I only claim a speaker is a Subwoofer if it is designed for frequencies below 30 to roughly 10 htz. Lol I play Bass guitar and mine plays down to 15 htz very nicely and can flap my pantlegs if I am standing in front of the speaker assembly. Keep up the good Isobaric information since people are generally ignorant about that type of speaker.
What are you using to hit 10hz ? 20hz is like a earth quake 😅
@@jacobclark89 I Have used audio generators to drive my Ampeg SVT PRO 4 amp into my discontinued model Bass Speaker Cab that has 4x10inch speakers and 3 ports that the spec says goes to about 28 htz. With 2400 watts and equalization it plays down to 7.5 htz but it takes a lot more power. I normally only play down to 15 Htz on the Bass Guitar in special situations for special effects. Lol
Nice experiment! JBL were masters at this... they added a 35g mass ring to the 2235 woofer, or left it out on the 2234. Various JBL woofers were paper but with sprayed on material to add weight and damping.
Ambitious project, very much looking forward for the result. I assume this is going to be at least a partialliy active design? With a separate amplifier and active filtering for the subwoofers? Passive filtering at 80 Hertz isn't something you really want to do. One more thing regarding the isobaric enclosure: Try to keep the amount of air between the two drivers as low as possible. You want a stiff coupling here.
The eventual plan is full active, for the three-way as well as the sub, but for now the subs will be driven from the subwoofer output from my 2.1 receiver with the crossover set to 80Hz.
Adding mass to the cone makes it harder to respond to pulses because of kinetic energy of the cone.
1:47
A very interesting and informative video! Thank you! Do you build bass guitar speaker cabinets?
Looking forward to the build, yup big speakers are a handful, had my fair share of moving live production speakers around. Heavy and awkward,
I decided to add mass by cutting a black piezo wire short enough to go around the outside edge of the dust cap on the active subwoofer in my guitar rig since it was already overdriven with a decent bass knob and power amp going through a stereo pedal. sounds perfect with a slightly deeper voice. It really brings out a layer of sub bass when you need it.
Ya, I’m getting into speaker building and yup everything is a trade of. No such thing as the perfect woofer just perfect for the needed application. Though I do collect old infinity perfect woofers.
jerry we need you. thank your for dropping the knowledge on the lo-fi's !!
looking forward to this design, not many use it.
These days most woofers are designed for smaller boxes, so there less of a need to use isobaric.
Can't wait to see more progress on those!
Gonna follow this project..
Werry good and interresting video, I'm allso interrested in speaker builds. I wonder what speaker design software are you using?
Man, 6:09, now thats a sexy looking speaker, John 😁👍
Wouldn’t a multi-band frequency equalizer accomplish a more accurate result, or are you merely building for your personal listening preferences?
What you suggest would basically allow the amp to increase output in the desired frequency range. The only way i can see weights increasing subwoofer output is by increasing excursion, because it isn't increasing cone surface area. Adding weight to a woofer seems like it would reduce efficiency and frequency response, and inhibit its' ability to hit higher frequencies. In my opinion, stay within specification. Don't modify your subs or add weights to increase excursion. If you want more bass, get bigger subs with higher excursion, more surface area, and stronger (bigger) magnets. Then get a stronger amp to match.
Like that idea about the weight never knew that like learning something every day and I have now
thank you 🙏 have a blessed day
Doing this is fine if you arent looking for max output, but what this is essentially doing is lowering the max output capability of the driver. You aren't actually getting more low end. The max low end of a driver is excursion limited, so that doesn't change based on the fs of the driver, however, the max output of midbass and high frequencies are power limited generally. This also means they are sensitivity limited. The era of full-range speakers is ending and for good reason, subwoofers can be placed in better modal areas and can do much more than most full-range speakers.
IMO it is never a good idea to intentionally add mass to a driver to get lower bass, you are better off using DSP to eq up the low bass because you'll still have the headroom in the midbass and higher frequencies. You can also tame peaks and modes to get much better sound quality.
Interesting, but I would advise against this is you have other means. Lowering the Fq does not really mean you get more bass. If you need a boost down low, then you can do the same with EQ instead of making the driver have a higher Qts and effectively lowering it's sensitivity. It will have to consume more power to deliver the SPL across it's whole passband esp. If it's a lot more mass
The most high end subwoofers typically have huge motors compared to their moving mass and low Qts. Mass is the enemy!
Final Fq is really defined by the system, not just the driver.
In short if you need more low end, pick a different box or EQ to driver if you need to
This might be a year old, but I just made a similar comment. I commend him for trying to think outside the box and post it on TH-cam, but I don't think this guy actually knows much about speakers. I wonder what his background is since he seems to misunderstand some very basic engineering principles in a few of his videos.
Did you find that your break-in period lowered the f3 at all? I've read that long (24 hours) burn-ins can gain an extra ~5db or so of lowered fs/f3. Very cool cabinet design.
There was a significant change after the first hour, Fs went down from 30Hz to 28Hz. But the second hour of break-in changed very little, so I don't see a need to go for much longer than 2 hours.
@@IBuildIt Neat, thanks :) That shows why you should burn in before designing the enclosure.
"he likes big speakers and he can not lie, other brothers can deny...
Good looking design!
Love the design! Can't wait to see the series!
Really looking forward to this project.
What model are those woofers? The sim results look great!!
I believe that because ,I had a pair of design acoustic speaker ,and the woofer had three piece of rectangular wood in it. and the base of that was unbelievable .to this day I haven't heard no bass like it
I used BBs for years glued around the dust cap with white glue to achieve a lower resonance. It is not a solution for all woofers but I have used for drivers as small as 4".
Nice shop john.
Fascinating trick.
What, if any, effect does this have on the impedance curve of the driver?
It's the David Hatcher Childress of Ancient Audio. Lol! Great video!!
I have built speakers and have poured through the speaker and vent hole floor-leveler cement to a thickness of about 5/8” for dampener. They sound good but I don’t have the equipment to test like you do, so I was wondering if you would do it. Obviously you have to pour in cycles since there are six sides. I got three side pours in a single day.
We have done this with Blu Tack. It works like a charm but looks cheap, as it is! You might prefer Blu Tack Black option or using with a grille.
Really love the speaker design/shape looks modern and beefy, cant wait to see the build.
Looking forward to this build. Nice looking speaker design for sure John. Keep up the great work! Can't wait to see how you finish them. I was thinking a nice veneer on the front panel and alternating w/ flat or gloss black for the triangular facet and then another wood veneer facet as you go around the sides and back. Really cool looking design. So wish we could hear them, I'm sure they will be awesome.
Fascinating John and a subject I really enjoy being a Hi-Fi nut.
Given there are difference shapes of enclosures in manufactured speakers, I'm guessing this *shaping* is important as well as the sizing ?
i used 2 car audio subs, a crown 1502 to power them, and made my own 3-way speakers with parts from partsexpress... It sounds way better than any store bought stuff i have owned in the past =) All sealed boxs.
Haha! I added mass to coax 6x9s by cutting off the tweeters & gluing on dust caps (castrol 1qt bottle caps w/ superglue 😂).
i did that years ago, in my car, & it still works fine.
Pardon my ignorance on speaker basics - would like a tiny direction for my problem. I bought a 8inch 50 watt woofer (not sub woofer) about 15 years back, used it for few hours and it sounded good. I opened it today and connected it to my amplifier and it outputs too little volume. I gently pushed the cone and spider up, and the volume goes up and it vibrates well. How can I fix it? The spider feels hard... the soft rubber on the outer edge of the cone is soft/flexible...
For the first seconds, I knew what you were going to do. So, if I do that with a woofer and a Passive radiator, I can go lower? (I might blow the speaker lol)
I just got a new subwoofer from Bestisan and it's a downfiring version. I also have it in a side firing version. Both have the same amp and woofer. Only thing is the downfiring one has one small rubber pad stuck on the dust cap off axist. Is that a mass pad of sort or was this a repair? I'm stumped cause it's new out of the box and I've never seen this before. 🤔
Very interesting video
great vid, yea the tittle is a very good magnet...
what software is that. I also do my own speakers boxes, if you can help me i want to make some new boxes for 4 15s inche woofers. I want a punchy bass that would be feel on you chest than a bass that make everything rattle, i want to keep these compact and light. since ill be using these in my lil gigs...
would it be possible to do something like this to a commercial speaker after taking it apart? I bought a beosound explore but the bass is zero even with app fine tuning.. and looking to add little bit of bass to it
How did they turn out?
Fascinating. I'm kind of surprised I've never heard of the isobaric configuration before. I'll have to go look into the physics and benefits of using it are.
If I had to guess off the top of my head (and as you elude to in the video), it sort of simulates a larger enclosure volume? Almost like a port, but... active? I'm probably way off.
These are not active design.
These are passive design.
John will be using passive crossovers to regulate where each signal will be going to,ie: sub,bass,mid,treble.
Active, uses a active crossover that is adjustable,electronic circuitry. Put that straight into the amp,straight to the speakers.
@@xmachine7003 I was talking about the isobaric subwoofer enclosure. Having two drivers in the same chamber.
Does adding mass affect the Q?
This will bee interesting to see and learn.
I built very similar set of speakers. Use Emmence drivers in an Isobaric arrangement in a sealed box with a 15 driver upper section. When used for two channel listening the bass is punchy and clean. In theater use I have numerous additional subwoofer.
Doesn’t isobaric require the drivers to be facing each other and out of phase with each other?
This technique was used years ago by Kenwood . On the drone cone I believe.
The system was supplied with a couple of screw on weights.
Breaking in .... Guitar strings are the same. A new set tend to have a jangling sound then settle in and become sweet then latter sound dead.
The best way to add weight to a woofer it's painting them with some thick flexible paint
Sorry for the question is it called loosing "sensitivity" or efficiency? Sorry asking for a friend thanks.
Same thing really. Acoustic efficiency might go from 2.5% to 2%, while sensitivity might go from 92 dB/W/m to 89... or something like that. They’re the same thing but using different units.
For the ever so slight increase in the bottom octaves, it looks to take too much of a hit along the rest of the frequency curve, however, it would be more useful if it better balances the overall output of a speaker at a given power applied. Wouldn't changing the crossover do the same?
I am interested in these metal rings to add the mass to a woofer. Whered you get that? I have some 18s with an fs of 32 and i like it more like 28 or 26 hz. SO can i add a ring to my woofer like this to achieve the fs i want?
Question: I just received a Yamaha soundbar and a SHU sub... I tried hooking it up to my bedroom TV (Sony A9S Oled 48"), The light's are on on the Sub, I have the sub connected to the Soundbar but there's no sound from the sub. The soundbar plays but not the sub.
Suggestions?
Thank you
Joe
That's the secret to the under-seat subwoofers. I have a Blaupunkt powered subwoofer and the center cap came unglued, making a horrible amount of racket. When I removed the cap, I found it is made of a heavy piece of metal. Adding weight to a speaker slows the cone down. It's like a mechanical crossover. It doesn't make it hit the lows harder; it simply rolls off the higher frequencies.
What’s that Woofer you have there ??
how much weight can be addedd? If i model stuff on winISD it seems like the more the better when it comes to bass, how do i evaluate the power trade off?
Can i paint my b&c 15 inch woofer so it can handle more wattage
In love with the angles of the tower/boxes. I have skinny towers compared to the width in your design.
The double woofer stacked weirds me out. Never seen it before but very interested in how it really adds up with the math for power.
My cone is so little on my speaker. I literally see more speaker than cone would this method maybe work better cause, The fact that cone is small?
I found a 1000 watt active PA speaker with a 12” woofer and I’m looking to replace the woofer with the deepest subwoofer I can find. Any suggestions? Am I crazy?
I’m new to sound systems and i would like some deeper bass out of my sub, it’s a jbl powerbass 10, how would I know how much weight to add. It’s a good thing I saw this post as I was gonna go and just randomly throw on 14 grams
You could add dots or strips of glue and test it out at different masses.
How can you measure vibration of woofer or bass? My neighbours are annoying ..pls help
So dusty subs go lower?
Are you using these speakers for less sound and more SPL?
I think what you are asking is if I'm sacrificing sound quality for higher output, and the answer is no.
Adding poly-fil to an enclosure will do some good also.
Did it 54 or so years ago - probably something David Weems mentioned - bet Qts was already "ripe" w/o the added mass ;^)
In these days, adding mass intentionally means something between not having tools, not having options, not having the right speaker or not having the right design. But one still can encounter such situation. At that moment, it is a good lesson.
Could you expect to see the same 9 fs drop for any woofer by adding 14g to it, or is it more of a specific to each application?
I use subs in car audio and was wondering if this would work the same.
This is very specific to the woofer you use and isn't a good solution unless you have the means to determine that.
With all else staying constant on the woofer, how does it play any lower? Yes, the F3 is lower, but that doesn't mean anything since the xmax and the motor BL is still exactly the same. Even the screenshot of your F3 and the frequency response shows exactly what I'm saying. Sure the F3 dropped, but that's because you lost like 3db above 35Hz. That doesn't mean you gained anything below 35Hz. If you want to change the frequency response, you could easily do that with a DSP, no need to add mass.
How does adding mass boost the SPL of the lower frequencies? I feel like I'm missing something.
Yes sir you are correct 👍
More mass will also affect how the woofer’s damping. It may ring on an impulse longer. It would definitely need to have the correct sized cabinet.
Looking for low volume n deep bass..n b able to have a Convo ..
Would it be the same for car woofers like a skar zvx 12