In todays video, we tackle an older Bowers and Wilkins that had some good bones with questionable engineering! Enjoy this one! What the HECK?! Bowers and Wilkins
Not to be difficult but I've spent a fair amount of time with B&W's engineers in the UK. They know what they're doing. But what they're doing, in this line, is not making the most accurate speakers possible. The dip makes for a more "impressive" sound to a less discerning listener. The 4K peak is symmetrical and should have been easy to deal with in the crossover, unlike typical metal cone multi breakups. The 1K is part of the typical B&W Kevlar woofer/mid "cone cry". (I was a dealer for 25 years). I thought there was a lot o hash in the high frequencies time response (I used a MLSSA FFT for years). Winding up, flat frequency response can be worse if you flatten it by using crossovers that cause ringing. Oh, few speakers are phase coherent. The ones I'm using are but they're in a small minority. These were made to a corporate budget with 45 points by a large company and were a huge seller. Good for business, not a great speaker, as you say.
Are you kidding? B & W wanted these to sound like crap? Those measurements reflect the sound and that response is terrible. And if loved these the get the wax out of your ears.
Listening 4 to 6 hours of music every day as a recording engineer, I can certainly appreciate the value of smoothness of response and phase accuracy if you want your hearing to remain intact overtime. Good work, Danny!
It took me 60+ hours. I had to make standoffs in my metal lathe to layer these large, custom-made circuit boards, just to squeeze them in there, which was a challenge all its own. One has to decide what one's time is worth. As Danny had said in one of his videos to the effect of spending more money on speakers will still get you cheap crossovers is a true statement. That's why pro audio monitors for home listening is the answer. The future is here.
I think I can help here. In the mid 90s Kevlar mid ranges were very popular because they had the sonic advantages of paper but with superior durability. The problem with Kevlar is that 4k 'honk' . It requires a pretty aggressive crossover to integrate properly, but once its tweaked right its glorious. Beats the poly and composites based mids used by focal and others during that time, especially in transparency.. However, the CDM1 was "broken' from the start. Hifi dealers near me mocked it, but there were customers that preferred ear bleed upper mids. The same driver was used in Matrix series with better crossovers.
I just completed this upgrade. I own two pair of CDM 1NT speakers, with serial numbers about 25K apart. I upgraded the older pair. I did an A-B comparison spread over the last two days with a variety of hi-fi music off TH-cam connected to a good-quality NAD receiver. The upgraded pair was warmer and fuller in the midrange, with improved stereo imaging. The original pair was more "scooped" in the midrange, with bright high-hats and female vocals, but seemed to suffer from a "tin can" kind of sound when compared to the upgrade. Some musical instruments almost disappeared in that scooped midrange. Also, with the original pair, the sound was clearly coming from the speaker cabinets more than creating an in-between sound stage like the upgraded pair. The upgraded pair also seemed to have more extended bass. For fun, I ran a straight 32 Hz signal through both pairs - the upgraded pair reproduced the signal without any noise or transients; I couldn't say the same for the original pair. If you are thinking of taking this on, keep in mind that you will get a bag of RCL components that you must build a board out of - I built 4 boards, total. Then I had to figure out how to find space for them in this small speaker, so I layered them, making dual-shouldered standoffs on my metal lathe. Electronics are not my strength, so I grew a little during this time-consuming exercise. Danny's tutorial videos on the GR-Research website were very helpful in accomplishing this task. If you are skilled at these things, and just throw things together, you might be able to do this in 8-10 hours. I spent several times that amount time since this was way out of my comfort zone. In the end, I think it was worth it. However, I probably won't be upgrading the other pair because I may be able to find speakers that sound better that I can replace them with, and will not involve any more of my scare spare time.
Thanks for sharing. I just ordered the upgrade kit for my 602s and I am both excited and nervous! Nervous not about the sonic change yet rather being able to pull this off. My very handy buddy is going to help me...more like he's gonna do it! Anyway ill keep you posted when it happens. I wonder if mine will take around the same time or less, it may be slightly less involved. Cheers.
@@techsamurai11 I'm not really set up to do that, although I do have a single pro-level mic. Also, I gave the un-upgraded ones to my son - that will save me 50 hours of time (I figure I can do it 10 hours faster the second time) fixing someone else's work. If you only own one pair, and you have the time and patience to figure out how to build those boards, and squeeze them in there (like I did, piggybacking the tweeter and woofer crossover boards on each other), then you will be rewarded with a much richer, 3-dimensional sound. It will be very different from the original, I can tell you that. You can always save the old boards if you want to revert back to the old sound, but I highly doubt anyone would want to do that since the improvement is quite stark.
I own a pair of these & have really loved them but I’m open to doing the upgrade, did I miss though where to get all the parts for the upgrade? Do you have link & what to get so I can check it out:)
Great video as always, informative and entertaining. Its intresting to learn about other company's products and how they made them. Happy New Year and looking forward to your next video.
I'm marvelled at the luxury we have getting first hand unbiased information about products makers offer to market blowing their own trumpet and we unarmed caught up in their hipe. No more with a person like this. This is truth revealed. Seeing how disconnected reality is in many times compared to the promises makers do helps us to separate grain from the wheat. Good job!!!
Great video. Complete and comprehensive explanation. Also, saving up for some Encores, hope the parts and tweeters will be available again in due course.
entertaining to see autopsies on the sacred cows of audio!! and to see the curtain pulled back on the revered names in speakers, and the brutal truth told. a great education in speaker design, thanks!
I remember a time I enjoyed a portable tape deck very much. It had two speakers that could be removed from the central unit and placed and adjusted to your personal needs. It also had a 7band EQ. One fine day, my evil mind decided to unscrew the speakers to find out how does it make such great sound. I was devastated to find out that the tweeters on those speakers were for show only. All it had were a L+R full range drivers. I could not love it anymore.
Great video, I remember that this model was not that well received at launch. Considering that these are some years old, have you ever checked both speakers to see if aging has altered them? My old Proac Studio 3 were different until the crossover components were replaced. Thanks for well explained technical information, even though I have done 40 plus years doing technical work, there's always something to learn and enjoy!
I did A-B listening tests between both pairs of CDM-1NTs, before I upgraded the older pair, which had a lot more miles on them. I could not detect any audible differences between them, which bode well for detecting any improvements after upgrading one pair with the GR-Research kit.
Nice upgrade. If I'd see a dip like that in the xo point, I would think polarity issue. (If you connect both drivers in phase in a second order you get this type of response, not summing) I assume you checked it before the upgrade? :) I had this problem when working with an older JBL driver, they where always reversed + and -.
There's other objective review channels out there. Sure they don't have a business of upgrading existing speakers, but they do measure stuff. Anyone involved in typical hifi has to sell a story so you'll only get info they want you to hear. Even Danny does this somewhat as he runs the line between objective and subjective when it comes to certain things imo.
@@RennieAsh wow. you r a genius. thnks for pointing this out. i never realized this was not the only you tube channel for audio info. as for telling me what i want to hear.... hahahahahhaha
I would love to see you try to fix a Wilson. They do on purpose what is generally regarded as wrong. Like making all the drivers out of phase of ever other drive.
I've been watching and enjoying your channel for about a half a year! I really appreciate your methodology and presentation! Would you consider including info on what values are on existing caps, resisters, and inductors on the x-overs and what and why you are using to correct these speakers? I'd also like to request larger views on the response graphs, as they are unreadable my phone, my most used device? I'm aware that the first two requests may be too much info to give away but thought I'd ask anyhow! Thanks much for the valuable content you bring!
Inductors would have to be measured out of circuit if not written on component, so I guess only happens if he actually dismantles the existing crossover. Caps and resistors could easily be read.] Of course he won't tell you the upgrade kit values otherwise his business wouldn't work lol
Thank you, now i understand residual ringing, that being said which tower speakers nowadays do a good job at it while being affordable (accurate sound)
Hey Danny, respect the work you are putting in in the speakers! Question, have you ever modded or had a look at the JBL Ti10k, Ti8k or Ti6k speakers (the pyramidal ones)?
Finally a video without Danny's usual audio cuckoo-ry (burn-in, cables, etc). He stuck to fixing some obvious shortcomings, and before / after comp, using, wait for it... Science ! Good job on this one. Would really love to do a listening compararison before / after for myself. Though I wanted to, I could never like the sound from various B&W speakers I auditioned (15 yrs ago). Very curious to see if such changes could have helped...
The sound did change dramatically with this upgrade. While I liked the sound before the upgrade, I didn't know what I was missing. I think B&W had voiced these speakers to draw attention on a showroom floor rather than voicing them for long- term listening pleasure.
Have you checked before a vintage Dynaudio T330D tweeter and found that the foam filling the vented pole behing the dome, that foam is disintegrating? This happened to me with my TAOC FC3000 stand loudspeakers. I was irritated by the harsh and beaming sound of that tweeter. The integration between midwoofer and tweeter was awful so I thought something was wrong. I opened and found the culprit. Miraculously, those grains of dry foam didn't enter in the magnetic gap yet. I changed the bad stuff and put something similar without good results so I changed that for that synthetic cotton used in loudspeakers fillings and the sound got much better. Nonetheless, there are times still in which the tweeter breaks the illusion of a whole soundstage. This doesn't happen with the Sony APM 66ES MK II. This latter sounds more of a whole despite being a three way loudspeaker.
This is what B&W was thinking - "what can we do to reduce the performance of the CDM series bookshelf so that it doesn't match or exceed that of the 800 series bookshelf, but is above the 600 series bookshelf speakers?" Enter the CDM1 NT's ringing, out of phase, dips, peaks and valleys!
Hello Danny, would you be able to do the B&W CDM 7NT at some time in the future? This speaker is, I think, still used a lot and as you looked at the CDM1NT and improved, it would be interesting to look at the CDM7 too.
I still have a pair of B&W P4s which use basically the same derived drive units but in a tranmission loaded cabinet. In those days (circa 1998) I knew absolutley nothing about speaker design and like many others relied on british HiFi magazines to review before hearing. Now as a speaker designer myself, I realise that many of the writers were just uninformed hacks pretending they knew one end of a frequency response curve from the other and I saw many times them claiming that the designers did not set out to create a flat response. Some of these idiots would go as far as to say that a flat curve sounded 'flat', 'lifeless'. Go back to the What HiFi and Hifi Choice of the day.... Clearly, if you start off with a 'wild' native curve from the driver itself, you are going to need a lot of crossove parts to tame it and get the summation right with other drivers. The curious thing is that the B&W mid/bass driver was not cheap driver at the time. It was cast aluminium and used Kevlar which was relatively new to speaker design. Its bright yellow woven design was probably a gift for the marketing department however. So perhaps more style over substance. As Ritchie shows, B&W started off with something that had a wild response and so was flawed from the beginning. Incidently, the crossover parts used on these are dreadful and sparse, so the wild response will not be tamed adequately or in any refined way.
I remember listening to some very early (mid to late 80s) B&Ws and thought they sounded quite good (never bought them, though). Later in the 90s, I went stereo shopping again, and listened to a line from that time. Everyone used to give B&Ws such high praise, but when I heard a pair, I thought 'ew, what the f...?'. I couldn't believe how bad they sounded, after having such a good rep/ well-thought-of brand.
@@BobbyDazzler888 I can't recall what model they were - long time ago. They had their new-at-the time yellow drivers. They weren't cheap speakers, either... they were around 1400 bucks or so (CAD) back then, which would translate to around $2400-2500 now. And yes, I'm aware that B&W makes a wide variety of speakers. I'm not really a huge fan of any of them, tbh, - at least not by comparison to many other brands.
I bought a pair of DM 220's when I was 15. And the original 600 series when I was 26. Never harsh. On the contrary. Never overly bright .. and these were my young ears... Lol.
Learning loads here. I have always built my own speakers using good quality drivers but never happy with the results... Now I have a woodshop and time, I just need help on the design end.
I would like to know your opinion of Henry Kloss.. part of his speaker design involved voicing by ear... how would that impact a clinically flat response? Knowing our ears are more sensitive in the mid range, doesn't an absolute flat response translate into a forward midrange?
Great video yet again - would love it if you did a video talking about different subjective sounds of different common speakers drivers, particularly with regards to different materials (paper vs Alu etc…).
SB Acoustics is a good example how different cone material sounds despite all other parts being the same. Their Alu cones are very good, possibly one the best available. The poly is not as detailed as alu and easier on ears and to design filter. Paper cone again sound different. All of the drivers have cone break-ups that have to be well controlled to get good sound from them. They have copper rings in motor to reduce distortions and lower voice coil inductance but it could be improved together with suspension to get better low freq distortions numbers. Again these are not expensive drivers.
I bought a pair of cherry CDM1's years ago and still have them along with the center channel. It was all I could afford at the time. Seems like I've been tweaking them for years to get them to sound decent. I have a bit more money these days, any suggestions on what I should be looking at to replace them?
Thanks for the reviews. I wrote a while back about sending in my pair of the B&W CDM-1NTs, CDM-9NT. It's the same tweeter and woofer but with 2 passive radiators. I assume that the upgrade for the 1NTs would be different than the 9NTs. You would want to test them specifically, correct? 👍
You mention ringing in your charts, could you show what no ringing would look like? or somehow demonstrate what ringing would sound like? assuming TH-cam videos would allow this.
Re not aiming for flat response...yup it happens...a lot! Admittedly mostly at the low end with poorly tuned boxes intended to cause a lump in response around 50hz to make it seem to be producing bass.
My friend watching two of ur videos I see how ur doing ur reviews which I have never seen. I have a pair of jvc MK2 cabinets with peerless bass drivers. I am looking for a tweeter mid set up to match the peerless. The cross overs I need building as well any thoughts.
I picked up a pair of these speakers in good condition for $30 from Goodwill. I am not an audiophile, but I do appreciate good sound. I will keep this video for reference. I love to tinker.
With all due respect, you are doing a great job and sharing gives the hobbie a way to see what is behind some of your improvements. I do have a question: Could a physical application of damping material... "treated string" on the legs of the frame? Cheers!
I purchased B&W DM2000 in 1985 and they came with a frequency response plot from 20 to 20K that was essentially flat over the range. They have a lable on them stating "electronic time delay". I have always loved them and still have them hooked up to a high current Adcom amp and Hafler preamp. The Adcom seemed to open them up compared to my Hafler 220 amp. I have never cared for the 'loudspeaker' sound from a JBL or Klipsch. Did these speakers you are testing originally come with a frequency plot from the factory?
I run an ancient Arcam alpha 9 and 9p power amp combo and that does the "opening up" trick on all manner of speakers from cheap Mission 763 and Heybrook HB1 to very expensive (to me) PMC Twenty 26 they give an effortless quality to everything, even though differences are obvious but they improve everything I've heard and I won't ever part with them.
Learn some here and specting to learn a lot more! Thank you Sir.🫡 After 43 years of life, a musician grandfather and other family members alike, Iv’e been drawn to music and combinations of tones making this armónica… music. I’m just starting in the HI-FI or HI-END speakers. Just got a chance to grab a couple of Paradigm’s floor towers. Paradigm 7 4v’s and the 9, Both for $250 in mint condition. I’m NOT a audio file person, but have been in concerts and in between instruments of all kinds being myself musician, the clarity of this two, Paradigm 9 as front L&R and the 7 4v for surround… Let me tell you something… Closed my eyes in the center, I can hear the buttons of instruments pressing befor the tone comes out😳, IMPRESIVE! The tweeters resonating just like a gritar metal string…🫠🤤 But I lack of a nice entry DAC or a nice HI-FI receiver or something, not to expensive but can get this AWSOME speakers to the next level or Better or fuller potential. I know for fact this speakers can sound much, much better. I just got a YAMAHA RX-V683 receiver🤦🏻♂️. Recomendations please…🙏🏼 Thank you!
I’m designing a speaker with two separate crossovers (one neutral and one v-shaped). Any suggestions for a good external switch that is not ferromagnetic?
6:45 How about the first floor reflection (as mentioned from 11:57 onwards)? Many designers incorporate that in their design, especially for a carpeted floor.
A few years ago I bought a pair of these on the used market. Listened to them for two days before deciding to resell them. Terrible sounding speakers to my ear. I've come to understand they were pretty typical for B&W.
Do you have these? How resonant are the cabinets? Are they braced at all? Could they be rebuilt "as is" using a thicker, better braced cabinet with a sheet of "no rez"? They look intriguing for the price for sure.
Danny, just heard about Linkwitz Orions, and went to the Linkwitz site where he preached "open baffle", same as you. How would you compare a Linkwitz OB design to yours? Id like to see Vandersteen speakers reviewed; they were the competitor in the 1990s that Wilson Audio was watching, along with Eggleston.
Danny, are you familiar with the “BBC dip?” There was a time when it was common among British speakers to see a dip of a few dB around 3 kHz, based on thinking that this is where the ear is most sensitive, and it would yield a subjectively more natural sound. I’m not passing judgement one way or the other, but there certainly have been designers who deliberately design an error in.
Yes, I am very familiar with that. It is an EQ to the amplitude. In this case the dip is caused because the drivers are not in phase very well. It is not on purpose.
@@dannyrichie9743 yes, I understand. I just wanted to point out, for people who don’t know, that sometimes deviations are intentional. That B&W woofer is a train wreck!
Yes I remember going to an Audio trade show years ago and a certain person from a company I wont say said yes the mid range is the most sensitive to the human ear so to cover up our speakers have a nice deep in that area to hide any problems
That BBC dip was designed in at the behest of the BBC outside broadcast unit who wanted a speaker that above all other considerations sounded good for the human voice, natural and very intelligable. They do sound good in that region for speech and uncomplicated music types. Rolled off bass and a lack of airiness in upper treble is seemingly the price, but they had to be small too so I think perhaps that is more the reason for the lack of bass. I like that signature if not over done, but these B+W are not that, they are just choppy like a rollercoaster from that awful looking graph, lol.
@@englishsteve1465 It’s interesting that it has quite a ripple effect. I have measured fairly new Spendor speakers that still have it. They were otherwise fairly flat and well-behaved.
With this being a 20yr old speaker, I wonder if maybe the rubber surround on the woofer has dried a bit, and is not damping the resonances as well as it did when it was new? B&W was always SO proud of their Kevlar drivers.... was it really more about looks and advertising than performance?
@@dannyrichie9743 as are my woofers from my 1985 BW DM2000s.. I actually blew one (actually my son blew it pushing the tape monitor button with the volume way up), and they replaced it quickly.
Focal used a foam under fiberglass or other material used for W cone. The foam would damp the resonances. Since they don't sell products to diy community for past two decades I don't know how the current drivers measure, but the 4kHz resonance is very much given for this size of the cone. Focal older K series seemed much flatter than this B&W midwoofer, the W had some rise in freq but can't recall how they compare against B&W. Polydax also used Carbon fiber cones or something similar in the '90s.
I got a pair of Klipsch RP-150M for $175. Is this a speaker that would be worth upgrading the crossover? They are okay for the money but how much potential do you think they have?
I have pair Snell E speakers that need a real facelift. They have great reputation. The pair I have is very early numbered pair, that Peter Snell gave to a friend of his that owned dbx another defunct audio company of the 70’s. The crossovers are original but are also a real mess, cludged together and hot glued to the back of the cabinets. I never use them because they just sound so blah. Any advice?
Hi! I enjoy your videos very much. But I have not seen them all. I just wonder if you also listen to the speakers before and after your modifications? I ask you because I dont hear that you say anything about the sound, before and after your work. You only show the measurements, witch is very interesting I have to say.
Danny, could you explain something for me that I don't quite understand. You said speakers that measure accurately could sound dull or could sound like live music. If you have two speakers that both measure similar and are accurate, what would make them sound so different? Driver specs and quality?
Hello. Very interesting video. I have some possibly older B&W 703s, which have never given a satisfactory sound. Opaque tweeter, in consideration of the promise of brightness for being a dome based on the B&W Nautilus. Correct but not well defined mids (the SONY SSCS 5 minimums far exceed them) and the bass is almost non-existent. Each one weighs 27 Kg (60 Lbs) and despite their large cabinets, the sound is disappointing in its depth. Will they have the same problem that you mention here?
Possibly, best if you find diy speaker builders where you live that have decent measurement system and can redesign the crossover - they're all over, but don't advertise them selves unlike B&W. One thing with Bowers, they're always treble bright with recess in upper mids/lower treble.
The bundling at 3kHz is usually the problem where the wider dispersion of the tweeter takes over. I think that is what the suckout on axis is intended to compensate for, reducing the horisontal power response around 3kHz. To make it sound less forward and shrill. I’m not so sure the usual vertical suckouts would compensate for this. Otherwise I fully agree, the resonant woofer and equally distant reflective grille is just bad design. Keep up the good work!
We only ever see freq. response at 1 watt. I realize that is the industry standard. But, does freq response change much if you use higher power to test (like 10 watts)? I think that would be an interesting comparison to see how the freq response changes versus power applied. Especially on "poor" speakers vs "good" speakers.
Gotta say...best vid yet. When i saw the initial curves the fix was obvious IF the tweeter could take it...so lower cross and steeper filter is a no brainer fix for a lot of whats wrong with the factory design. Gotta agree...B&W...what were you thinking? Kinda surprised.... But huge difference from tube connectors??? Afaik...in the same category as worrying about fm reception on speaker cables.
Seems like it might have been better to replace the woofer and simplify the crossover but I guess everybody covets the B&W name. I can only guess that even though you address the stored energy problem that there might be instances where it still might be a problem. Also I wonder that if you addressed the issues with that speaker, how do you know that other batches of the same speaker would behave the same way and would require a different corrective action?
I agree. Without at least one more pair of these speakers to test you couldn’t assume that they are all like this. Especially given their age and not knowing how it’s been used or abused over the years. I actually own a pair and while I feel compelled to do this upgrade I don’t have the equipment to test myself to see if mine have similar results.
@@wolfsburg696 I don't have the equipment either but for just a few bucks I picked up a calibrated microphone for my phone from Part Express. Assuming you've got the 3.5mm connector, play some pink noise through your speakers and see if you can see an odd frequency response. PE# iMM-6S
How do you know if a dip is due to cancellation due to phase shift vs simply lower magnitudes? It would be cool to add a curve of tweeter alone plus woofer alone and the delta between that total and the combined curve might indicate phase issues ?
This B&W upgrade may be winner of the "Most Significant Improvement" award. Looks like a great value for folks who own these. I kept a pair of B&W as limit refernces when building speakers. It"s easy to climb the attractive detail ladder when tuning, but when they are bright as the B&W reference set - I'd gone too far. I sold those last year and my Martin Logan e-stats, which served as a reference of transparency.
6.5" woofers all have a peak @ 1 khz. Sour med compared to 3" 4" 5" full range drivers (with a shallow cone). The difference is stark hearing these after hearing 6.5" two ways.
Hi, my 1NT sounds some dull just like sounds blocked by a wall like screen whatever amplifiers are matched. Some dull heavy sound. Any reason you could know how to change? Because I compared with other CDM 1NT users, I could clearly understand mine has some issue with drivers or any. I really love this for many years and want them stay for much longer with me. Thanks.
Hi Danny, Thanks for the video. Once more I see that you cross a tweeter an octave lower. Of course this improves vertical dispersion and sometimes frequency response, but I never see you measuring THD/IMD. I would be very cautious to cross tweeter that much lower. As you know, designing Loudspeakers is a matter of comprises. Chances are that the modified speakers will sound strained, distorted at high level playback. In addition, this is a lot more power into the tweeter which might be damaged because of this.
Regarding the tweeter and a crossover over point. How high or low it is crossed is not an issue. I look at the Fs of the tweeter and try to make sure that it is down in output levels at that point. Sometimes I cross the tweeter lower but there is less strain on it than before as the output down low (at its Fs) has been reduced.
Does your "new construction" include an anechoic chamber? I'm assuming the room you are currently testing frequency response in, is inadequate due to your frequency response charts all stopping at 200hz....
We built an anechoic chamber in our first building. It is a big expense, and 99% of what I need to measure I can do outside the chamber using a gated time window.
can you explain why speakers ring? was it the frame with the skinny posts? no! right because its cast. the woofer is kevlar so why would that ring? is being too stiff a problem? ive heard about “proper dampened speakers”. also aware of breakup modes in woofers. thats why you want a stiff speaker. im really interested in this stuff. is it something that is magical? as in, it happens randomly or it doesn’t. like they spent all that money on R&D’ing this woofer that they past the point of no return (starting over). Please answer this in a video. im unaware how to become notified when receiving answers. thanks!
There is quite a bit of ringing in the cone material and it is typical of very stiff cones. A cone material with better damping (like paper) tends to not have as much of a problem. The frame on that woofer rings quite a bit too.
Kevlar like metal cone based drivers have more of a high frequency breakup. That is not to say they are bad just care needs to be taken in the crossover design so their response in that frequency area is minimized.
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Not to be difficult but I've spent a fair amount of time with B&W's engineers in the UK. They know what they're doing. But what they're doing, in this line, is not making the most accurate speakers possible. The dip makes for a more "impressive" sound to a less discerning listener. The 4K peak is symmetrical and should have been easy to deal with in the crossover, unlike typical metal cone multi breakups. The 1K is part of the typical B&W Kevlar woofer/mid "cone cry". (I was a dealer for 25 years). I thought there was a lot o hash in the high frequencies time response (I used a MLSSA FFT for years). Winding up, flat frequency response can be worse if you flatten it by using crossovers that cause ringing. Oh, few speakers are phase coherent. The ones I'm using are but they're in a small minority. These were made to a corporate budget with 45 points by a large company and were a huge seller. Good for business, not a great speaker, as you say.
Are you kidding? B & W wanted these to sound like crap? Those measurements reflect the sound and that response is terrible. And if loved these the get the wax out of your ears.
Listening 4 to 6 hours of music every day as a recording engineer, I can certainly appreciate the value of smoothness of response and phase accuracy if you want your hearing to remain intact overtime. Good work, Danny!
This upgrade definitely gets you there, if you have the time to do it!
@@abboberg What's a few bucks and a couple hours of work for at least a decade of enjoyment, right?
@@abboberg i prefer a speaker that gets it right the first time
It took me 60+ hours. I had to make standoffs in my metal lathe to layer these large, custom-made circuit boards, just to squeeze them in there, which was a challenge all its own. One has to decide what one's time is worth. As Danny had said in one of his videos to the effect of spending more money on speakers will still get you cheap crossovers is a true statement. That's why pro audio monitors for home listening is the answer. The future is here.
I miss these. ☹️ I was extremely happy with them. They sounded awsome.
Thanks for your time Danny, always a pleasure to watch!
I learned a lot because Danny explains technical topics very well. Great vid! Some of the best technical HiFi content on TH-cam .
He's technically good and honest till he isn't
@@giriprasadkotte9876 What's that supposed to mean ?
@@tomkershaw4384
Please watch his exposition on audio cables
@@giriprasadkotte9876 bro get a life
@@Starch1b2c3d4a
🤗
Great video Danny! Thank you for enlightening us! “Knowledge is king”
I think I can help here. In the mid 90s Kevlar mid ranges were very popular because they had the sonic advantages of paper but with superior durability. The problem with Kevlar is that 4k 'honk' . It requires a pretty aggressive crossover to integrate properly, but once its tweaked right its glorious. Beats the poly and composites based mids used by focal and others during that time, especially in transparency.. However, the CDM1 was "broken' from the start. Hifi dealers near me mocked it, but there were customers that preferred ear bleed upper mids. The same driver was used in Matrix series with better crossovers.
Brand loyalty vs loyalty to musical accuracy! Thanks brother!
I just completed this upgrade. I own two pair of CDM 1NT speakers, with serial numbers about 25K apart. I upgraded the older pair. I did an A-B comparison spread over the last two days with a variety of hi-fi music off TH-cam connected to a good-quality NAD receiver. The upgraded pair was warmer and fuller in the midrange, with improved stereo imaging. The original pair was more "scooped" in the midrange, with bright high-hats and female vocals, but seemed to suffer from a "tin can" kind of sound when compared to the upgrade. Some musical instruments almost disappeared in that scooped midrange. Also, with the original pair, the sound was clearly coming from the speaker cabinets more than creating an in-between sound stage like the upgraded pair. The upgraded pair also seemed to have more extended bass. For fun, I ran a straight 32 Hz signal through both pairs - the upgraded pair reproduced the signal without any noise or transients; I couldn't say the same for the original pair. If you are thinking of taking this on, keep in mind that you will get a bag of RCL components that you must build a board out of - I built 4 boards, total. Then I had to figure out how to find space for them in this small speaker, so I layered them, making dual-shouldered standoffs on my metal lathe. Electronics are not my strength, so I grew a little during this time-consuming exercise. Danny's tutorial videos on the GR-Research website were very helpful in accomplishing this task. If you are skilled at these things, and just throw things together, you might be able to do this in 8-10 hours. I spent several times that amount time since this was way out of my comfort zone. In the end, I think it was worth it. However, I probably won't be upgrading the other pair because I may be able to find speakers that sound better that I can replace them with, and will not involve any more of my scare spare time.
Thanks for sharing. I just ordered the upgrade kit for my 602s and I am both excited and nervous! Nervous not about the sonic change yet rather being able to pull this off. My very handy buddy is going to help me...more like he's gonna do it! Anyway ill keep you posted when it happens. I wonder if mine will take around the same time or less, it may be slightly less involved. Cheers.
Wow, you have 2 and one is upgraded and the other isn’t? can you post recordings?
@@techsamurai11 I'm not really set up to do that, although I do have a single pro-level mic. Also, I gave the un-upgraded ones to my son - that will save me 50 hours of time (I figure I can do it 10 hours faster the second time) fixing someone else's work. If you only own one pair, and you have the time and patience to figure out how to build those boards, and squeeze them in there (like I did, piggybacking the tweeter and woofer crossover boards on each other), then you will be rewarded with a much richer, 3-dimensional sound. It will be very different from the original, I can tell you that. You can always save the old boards if you want to revert back to the old sound, but I highly doubt anyone would want to do that since the improvement is quite stark.
I own a pair of these & have really loved them but I’m open to doing the upgrade, did I miss though where to get all the parts for the upgrade? Do you have link & what to get so I can check it out:)
@@jasondouglas1437 The GR-RESEARCH website has these kits available for you to buy, unless, of course, they are having supply chain issues right now.
Great as always!
Thank you for this one!
Amazing work again! Cheers!!!
Danny,
A quick ‘Thank you.’ for putting your vids out. Stay on the high road as always!
Great video as always, informative and entertaining. Its intresting to learn about other company's products and how they made them. Happy New Year and looking forward to your next video.
I'm marvelled at the luxury we have getting first hand unbiased information about products makers offer to market blowing their own trumpet and we unarmed caught up in their hipe. No more with a person like this. This is truth revealed. Seeing how disconnected reality is in many times compared to the promises makers do helps us to separate grain from the wheat. Good job!!!
Loving the vids, Danny. Keep em coming!
Great video. Complete and comprehensive explanation. Also, saving up for some Encores, hope the parts and tweeters will be available again in due course.
Thanks . I really learn a lot from these videos. Makes me want to send in my Klipsh to see if the base response can be tamed.
entertaining to see autopsies on the sacred cows of audio!! and to see the curtain pulled back on the revered names in speakers, and the brutal truth told. a great education in speaker design, thanks!
Like these teardown videos. Thank you.
I remember a time I enjoyed a portable tape deck very much. It had two speakers that could be removed from the central unit and placed and adjusted to your personal needs. It also had a 7band EQ.
One fine day, my evil mind decided to unscrew the speakers to find out how does it make such great sound. I was devastated to find out that the tweeters on those speakers were for show only. All it had were a L+R full range drivers.
I could not love it anymore.
Thank you for another great video. Some of drivers look like Totem used some of them in the past the rainmaker woofer looks like yours.
Great video, I remember that this model was not that well received at launch. Considering that these are some years old, have you ever checked both speakers to see if aging has altered them? My old Proac Studio 3 were different until the crossover components were replaced. Thanks for well explained technical information, even though I have done 40 plus years doing technical work, there's always something to learn and enjoy!
I did A-B listening tests between both pairs of CDM-1NTs, before I upgraded the older pair, which had a lot more miles on them. I could not detect any audible differences between them, which bode well for detecting any improvements after upgrading one pair with the GR-Research kit.
Danny, you and OCD Mikey got the high intensity work velocity. Loving my Pedest'ale Tower speakers.
Really great what you made out of these mess! 👍
Nice upgrade. If I'd see a dip like that in the xo point, I would think polarity issue. (If you connect both drivers in phase in a second order you get this type of response, not summing) I assume you checked it before the upgrade? :) I had this problem when working with an older JBL driver, they where always reversed + and -.
the ONLY channel that always gives you serious info. i watch paul mcgowen and always end up thinking i learned zilch
There's other objective review channels out there. Sure they don't have a business of upgrading existing speakers, but they do measure stuff.
Anyone involved in typical hifi has to sell a story so you'll only get info they want you to hear. Even Danny does this somewhat as he runs the line between objective and subjective when it comes to certain things imo.
@@RennieAsh wow. you r a genius. thnks for pointing this out. i never realized this was not the only you tube channel for audio info. as for telling me what i want to hear.... hahahahahhaha
@@veroman007 re-read your comment, genius.
I would love to see you try to fix a Wilson. They do on purpose what is generally regarded as wrong. Like making all the drivers out of phase of ever other drive.
I've been watching and enjoying your channel for about a half a year!
I really appreciate your methodology and presentation!
Would you consider including info on what values are on existing caps, resisters, and inductors on the x-overs and what and why you are using to correct these speakers?
I'd also like to request larger views on the response graphs, as they are unreadable my phone, my most used device?
I'm aware that the first two requests may be too much info to give away but thought I'd ask anyhow!
Thanks much for the valuable content you bring!
Lol
Inductors would have to be measured out of circuit if not written on component, so I guess only happens if he actually dismantles the existing crossover. Caps and resistors could easily be read.]
Of course he won't tell you the upgrade kit values otherwise his business wouldn't work lol
Thank you, now i understand residual ringing, that being said which tower speakers nowadays do a good job at it while being affordable (accurate sound)
Hey Danny, respect the work you are putting in in the speakers! Question, have you ever modded or had a look at the JBL Ti10k, Ti8k or Ti6k speakers (the pyramidal ones)?
No, not those models.
Finally a video without Danny's usual audio cuckoo-ry (burn-in, cables, etc).
He stuck to fixing some obvious shortcomings, and before / after comp, using, wait for it... Science !
Good job on this one.
Would really love to do a listening compararison before / after for myself. Though I wanted to, I could never like the sound from various B&W speakers I auditioned (15 yrs ago). Very curious to see if such changes could have helped...
The sound did change dramatically with this upgrade. While I liked the sound before the upgrade, I didn't know what I was missing. I think B&W had voiced these speakers to draw attention on a showroom floor rather than voicing them for long- term listening pleasure.
Have you checked before a vintage Dynaudio T330D tweeter and found that the foam filling the vented pole behing the dome, that foam is disintegrating? This happened to me with my TAOC FC3000 stand loudspeakers. I was irritated by the harsh and beaming sound of that tweeter. The integration between midwoofer and tweeter was awful so I thought something was wrong. I opened and found the culprit. Miraculously, those grains of dry foam didn't enter in the magnetic gap yet. I changed the bad stuff and put something similar without good results so I changed that for that synthetic cotton used in loudspeakers fillings and the sound got much better. Nonetheless, there are times still in which the tweeter breaks the illusion of a whole soundstage. This doesn't happen with the Sony APM 66ES MK II. This latter sounds more of a whole despite being a three way loudspeaker.
This is what B&W was thinking - "what can we do to reduce the performance of the CDM series bookshelf so that it doesn't match or exceed that of the 800 series bookshelf, but is above the 600 series bookshelf speakers?" Enter the CDM1 NT's ringing, out of phase, dips, peaks and valleys!
Hello Danny, would you be able to do the B&W CDM 7NT at some time in the future? This speaker is, I think, still used a lot and as you looked at the CDM1NT and improved, it would be interesting to look at the CDM7 too.
I still have a pair of B&W P4s which use basically the same derived drive units but in a tranmission loaded cabinet. In those days (circa 1998) I knew absolutley nothing about speaker design and like many others relied on british HiFi magazines to review before hearing. Now as a speaker designer myself, I realise that many of the writers were just uninformed hacks pretending they knew one end of a frequency response curve from the other and I saw many times them claiming that the designers did not set out to create a flat response. Some of these idiots would go as far as to say that a flat curve sounded 'flat', 'lifeless'. Go back to the What HiFi and Hifi Choice of the day.... Clearly, if you start off with a 'wild' native curve from the driver itself, you are going to need a lot of crossove parts to tame it and get the summation right with other drivers. The curious thing is that the B&W mid/bass driver was not cheap driver at the time. It was cast aluminium and used Kevlar which was relatively new to speaker design. Its bright yellow woven design was probably a gift for the marketing department however. So perhaps more style over substance. As Ritchie shows, B&W started off with something that had a wild response and so was flawed from the beginning. Incidently, the crossover parts used on these are dreadful and sparse, so the wild response will not be tamed adequately or in any refined way.
"... some of these idiots..." Well put together 👍
New
Subscriber. Love this!!
You’re a magician Danny, great job as usual.
I was afraid he was going to have to send it to Harbeth so they could make a 50-component crossover to tame that woofer...LOL...
@@rosswarren436 Harbeth? $$$$$! The owner would have to be prepared to spend a whole lot more mulla than the entire NEW B & W pair sold for!!
Have you ever done a review of CSS speakers? I would be interested to hear your opinion on their Criton 2TD-X Tower. Thanks for the video!
First of all, thanks! Any plans for the cdm 7 SE?
Or a better question, may I use these parts for that crossover?
I remember listening to some very early (mid to late 80s) B&Ws and thought they sounded quite good (never bought them, though). Later in the 90s, I went stereo shopping again, and listened to a line from that time. Everyone used to give B&Ws such high praise, but when I heard a pair, I thought 'ew, what the f...?'. I couldn't believe how bad they sounded, after having such a good rep/ well-thought-of brand.
Marketing first, logistics and design second, engineering a very distant third
bowers has numerous lines, so a decade later comparison is apples vs oranges
What model? They make many types at various prices and applications
@@BobbyDazzler888 I can't recall what model they were - long time ago. They had their new-at-the time yellow drivers. They weren't cheap speakers, either... they were around 1400 bucks or so (CAD) back then, which would translate to around $2400-2500 now.
And yes, I'm aware that B&W makes a wide variety of speakers. I'm not really a huge fan of any of them, tbh, - at least not by comparison to many other brands.
Interesting. I heard modem dm800s and they were great. I found them much better than the over hyped nautilus.
Nice one Danny.
Thanks for breaking it all down. 🙂👍
I bought a pair of DM 220's when I was 15. And the original 600 series when I was 26. Never harsh. On the contrary. Never overly bright .. and these were my young ears... Lol.
Learning loads here. I have always built my own speakers using good quality drivers but never happy with the results... Now I have a woodshop and time, I just need help on the design end.
I would like to know your opinion of Henry Kloss.. part of his speaker design involved voicing by ear... how would that impact a clinically flat response? Knowing our ears are more sensitive in the mid range, doesn't an absolute flat response translate into a forward midrange?
Great video yet again - would love it if you did a video talking about different subjective sounds of different common speakers drivers, particularly with regards to different materials (paper vs Alu etc…).
SB Acoustics is a good example how different cone material sounds despite all other parts being the same. Their Alu cones are very good, possibly one the best available. The poly is not as detailed as alu and easier on ears and to design filter. Paper cone again sound different. All of the drivers have cone break-ups that have to be well controlled to get good sound from them. They have copper rings in motor to reduce distortions and lower voice coil inductance but it could be improved together with suspension to get better low freq distortions numbers. Again these are not expensive drivers.
It continues to amaze me how 'reputable' brands so often fail your analysis.
This is the best explanation of speaker response you’ve done, Danny.
Agreed
What do you think of the Cerwin Vega XLS 215'S? Would love to see those upgraded.
I bought a pair of cherry CDM1's years ago and still have them along with the center channel. It was all I could afford at the time. Seems like I've been tweaking them for years to get them to sound decent. I have a bit more money these days, any suggestions on what I should be looking at to replace them?
Great that notch filter didn't spoiled the impedance....
Thanks for the reviews. I wrote a while back about sending in my pair of the B&W CDM-1NTs, CDM-9NT. It's the same tweeter and woofer but with 2 passive radiators. I assume that the upgrade for the 1NTs would be different than the 9NTs. You would want to test them specifically, correct? 👍
You mention ringing in your charts, could you show what no ringing would look like? or somehow demonstrate what ringing would sound like? assuming TH-cam videos would allow this.
Went through hifi hell with the 684 towers and rotel ra10 40w amp and cd player. Hollow/soft mids, all treble and some bass.
Re not aiming for flat response...yup it happens...a lot! Admittedly mostly at the low end with poorly tuned boxes intended to cause a lump in response around 50hz to make it seem to be producing bass.
My friend watching two of ur videos I see how ur doing ur reviews which I have never seen. I have a pair of jvc MK2 cabinets with peerless bass drivers. I am looking for a tweeter mid set up to match the peerless. The cross overs I need building as well any thoughts.
Danny, can you do a vid comparing the sound from boxed speakers / others as I've only ever heard boxed designs...am I missing out ?
I picked up a pair of these speakers in good condition for $30 from Goodwill. I am not an audiophile, but I do appreciate good sound. I will keep this video for reference. I love to tinker.
With all due respect, you are doing a great job and sharing gives the hobbie a way to see what is behind some of your improvements. I do have a question: Could a physical application of damping material... "treated string" on the legs of the frame? Cheers!
Those frames ring quite a bit. A little something to damp it out is a good idea.
I purchased B&W DM2000 in 1985 and they came with a frequency response plot from 20 to 20K that was essentially flat over the range. They have a lable on them stating "electronic time delay". I have always loved them and still have them hooked up to a high current Adcom amp and Hafler preamp. The Adcom seemed to open them up compared to my Hafler 220 amp. I have never cared for the 'loudspeaker' sound from a JBL or Klipsch.
Did these speakers you are testing originally come with a frequency plot from the factory?
I run an ancient Arcam alpha 9 and 9p power amp combo and that does the "opening up" trick on all manner of speakers from cheap Mission 763 and Heybrook HB1 to very expensive (to me) PMC Twenty 26 they give an effortless quality to everything, even though differences are obvious but they improve everything I've heard and I won't ever part with them.
@@englishsteve1465 thank you!
Learn some here and specting to learn a lot more!
Thank you Sir.🫡
After 43 years of life, a musician grandfather and other family members alike, Iv’e been drawn to music and combinations of tones making this armónica… music.
I’m just starting in the HI-FI or HI-END speakers.
Just got a chance to grab a couple of Paradigm’s floor towers.
Paradigm 7 4v’s and the 9,
Both for $250 in mint condition.
I’m NOT a audio file person, but have been in concerts and in between instruments of all kinds being myself musician, the clarity of this two, Paradigm 9 as front L&R and the 7 4v for surround…
Let me tell you something…
Closed my eyes in the center, I can hear the buttons of instruments pressing befor the tone comes out😳, IMPRESIVE!
The tweeters resonating just like a gritar metal string…🫠🤤
But I lack of a nice entry DAC or a nice HI-FI receiver or something, not to expensive but can get this AWSOME speakers to the next level or Better or fuller potential. I know for fact this speakers can sound much, much better.
I just got a YAMAHA RX-V683 receiver🤦🏻♂️.
Recomendations please…🙏🏼
Thank you!
I’m designing a speaker with two separate crossovers (one neutral and one v-shaped). Any suggestions for a good external switch that is not ferromagnetic?
6:45 How about the first floor reflection (as mentioned from 11:57 onwards)? Many designers incorporate that in their design, especially for a carpeted floor.
Alright, Danny, glad to you.
A few years ago I bought a pair of these on the used market. Listened to them for two days before deciding to resell them. Terrible sounding speakers to my ear. I've come to understand they were pretty typical for B&W.
It would be great to see the whole story here. How about the distortion plots at 86 dB and 92 dB SPL before and after.
Im curious what you find or could improve on the Magnat Transpuls 1500
Do you have these? How resonant are the cabinets? Are they braced at all? Could they be rebuilt "as is" using a thicker, better braced cabinet with a sheet of "no rez"? They look intriguing for the price for sure.
Danny, just heard about Linkwitz Orions, and went to the Linkwitz site where he preached "open baffle", same as you. How would you compare a Linkwitz OB design to yours? Id like to see Vandersteen speakers reviewed; they were the competitor in the 1990s that Wilson Audio was watching, along with Eggleston.
Danny, are you familiar with the “BBC dip?” There was a time when it was common among British speakers to see a dip of a few dB around 3 kHz, based on thinking that this is where the ear is most sensitive, and it would yield a subjectively more natural sound. I’m not passing judgement one way or the other, but there certainly have been designers who deliberately design an error in.
Yes, I am very familiar with that. It is an EQ to the amplitude. In this case the dip is caused because the drivers are not in phase very well. It is not on purpose.
@@dannyrichie9743 yes, I understand. I just wanted to point out, for people who don’t know, that sometimes deviations are intentional. That B&W woofer is a train wreck!
Yes I remember going to an Audio trade show years ago and a certain person from a company I wont say said yes the mid range is the most sensitive to the human ear so to cover up our speakers have a nice deep in that area to hide any problems
That BBC dip was designed in at the behest of the BBC outside broadcast unit who wanted a speaker that above all other considerations sounded good for the human voice, natural and very intelligable. They do sound good in that region for speech and uncomplicated music types. Rolled off bass and a lack of airiness in upper treble is seemingly the price, but they had to be small too so I think perhaps that is more the reason for the lack of bass. I like that signature if not over done, but these B+W are not that, they are just choppy like a rollercoaster from that awful looking graph, lol.
@@englishsteve1465 It’s interesting that it has quite a ripple effect. I have measured fairly new Spendor speakers that still have it. They were otherwise fairly flat and well-behaved.
With this being a 20yr old speaker, I wonder if maybe the rubber surround on the woofer has dried a bit, and is not damping the resonances as well as it did when it was new? B&W was always SO proud of their Kevlar drivers.... was it really more about looks and advertising than performance?
This woofer was in great shape.
@@dannyrichie9743 as are my woofers from my 1985 BW DM2000s.. I actually blew one (actually my son blew it pushing the tape monitor button with the volume way up), and they replaced it quickly.
They settled on the Kevlar as their material and stubbornly refused to alter course despite knowing it's inherent flaws.
@@bradleybeeson6932 what are the flaws?, I think those drivers were made by Focal
Focal used a foam under fiberglass or other material used for W cone. The foam would damp the resonances. Since they don't sell products to diy community for past two decades I don't know how the current drivers measure, but the 4kHz resonance is very much given for this size of the cone. Focal older K series seemed much flatter than this B&W midwoofer, the W had some rise in freq but can't recall how they compare against B&W. Polydax also used Carbon fiber cones or something similar in the '90s.
I got a pair of Klipsch RP-150M for $175. Is this a speaker that would be worth upgrading the crossover? They are okay for the money but how much potential do you think they have?
What are your thoughts on the comparison of Cj Bowers and Wilkins 705S2 and say the 800 d2?
I have pair Snell E speakers that need a real facelift. They have great reputation. The pair I have is very early numbered pair, that Peter Snell gave to a friend of his that owned dbx another defunct audio company of the 70’s. The crossovers are original but are also a real mess, cludged together and hot glued to the back of the cabinets. I never use them because they just sound so blah. Any advice?
I was actually thinking that Danny would start over with his own woofer... until he didn't.
Hi! I enjoy your videos very much. But I have not seen them all. I just wonder if you also listen to the speakers before and after your modifications? I ask you because I dont hear that you say anything about the sound, before and after your work. You only show the measurements, witch is very interesting I have to say.
Could the b&w thx fcm8 be something to upgrade? And of course the Bass unit pcs8 😉👍🏻.
Danny, could you explain something for me that I don't quite understand. You said speakers that measure accurately could sound dull or could sound like live music. If you have two speakers that both measure similar and are accurate, what would make them sound so different? Driver specs and quality?
Everything matters. Cheesy parts smear the signal and suck out dynamics. Higher quality parts can transform a speaker in those ways.
Hello. Very interesting video. I have some possibly older B&W 703s, which have never given a satisfactory sound. Opaque tweeter, in consideration of the promise of brightness for being a dome based on the B&W Nautilus. Correct but not well defined mids (the SONY SSCS 5 minimums far exceed them) and the bass is almost non-existent. Each one weighs 27 Kg (60 Lbs) and despite their large cabinets, the sound is disappointing in its depth. Will they have the same problem that you mention here?
Possibly, best if you find diy speaker builders where you live that have decent measurement system and can redesign the crossover - they're all over, but don't advertise them selves unlike B&W. One thing with Bowers, they're always treble bright with recess in upper mids/lower treble.
I have a pair of Those speakers. How can I acquire the cross-over you have made to correct the sound response?
I'd like to see what you think of the ABX Baffle project. Also, tube connectors for your amplifier? 2 💡 💡 💡 💡 💡 💡 ideas.....
The bundling at 3kHz is usually the problem where the wider dispersion of the tweeter takes over. I think that is what the suckout on axis is intended to compensate for, reducing the horisontal power response around 3kHz. To make it sound less forward and shrill. I’m not so sure the usual vertical suckouts would compensate for this. Otherwise I fully agree, the resonant woofer and equally distant reflective grille is just bad design. Keep up the good work!
We only ever see freq. response at 1 watt. I realize that is the industry standard. But, does freq response change much if you use higher power to test (like 10 watts)? I think that would be an interesting comparison to see how the freq response changes versus power applied. Especially on "poor" speakers vs "good" speakers.
It stays the same.
will the Behringer ECM8000 work good enough for my little project to measure my speakers ?
Hi Danny. Just out of curiousity, when there are driver issues, I noticed that you rarely (or ever) suggest a driver replacement. Is there a reason?
It would just become to expensive, and if that was the case he would recommend you just build one of his kits 🔈👍🏻
You can't just swap out drivers for different ones without revoicing the whole speaker. You might just as well start from scratch unfortunately
I had always understood the famous B&W mid-range drop-out to be part of their sound signature. ;)
The drop out is not in the midrange. It is well above it.
Gotta say...best vid yet. When i saw the initial curves the fix was obvious IF the tweeter could take it...so lower cross and steeper filter is a no brainer fix for a lot of whats wrong with the factory design. Gotta agree...B&W...what were you thinking?
Kinda surprised....
But huge difference from tube connectors??? Afaik...in the same category as worrying about fm reception on speaker cables.
Believe it or not, the audible difference form tube connectors to binding posts like these are clearly audible.
Seems like it might have been better to replace the woofer and simplify the crossover but I guess everybody covets the B&W name. I can only guess that even though you address the stored energy problem that there might be instances where it still might be a problem. Also I wonder that if you addressed the issues with that speaker, how do you know that other batches of the same speaker would behave the same way and would require a different corrective action?
I agree. Without at least one more pair of these speakers to test you couldn’t assume that they are all like this. Especially given their age and not knowing how it’s been used or abused over the years. I actually own a pair and while I feel compelled to do this upgrade I don’t have the equipment to test myself to see if mine have similar results.
@@wolfsburg696 I don't have the equipment either but for just a few bucks I picked up a calibrated microphone for my phone from Part Express. Assuming you've got the 3.5mm connector, play some pink noise through your speakers and see if you can see an odd frequency response. PE# iMM-6S
How do you know if a dip is due to cancellation due to phase shift vs simply lower magnitudes? It would be cool to add a curve of tweeter alone plus woofer alone and the delta between that total and the combined curve might indicate phase issues ?
I do that. Those measurements are in the video.
Have you ever tested any of the Aerial Audio speakers?
This B&W upgrade may be winner of the "Most Significant Improvement" award. Looks like a great value for folks who own these.
I kept a pair of B&W as limit refernces when building speakers. It"s easy to climb the attractive detail ladder when tuning, but when they are bright as the B&W reference set - I'd gone too far. I sold those last year and my Martin Logan e-stats, which served as a reference of transparency.
It would be cool to see the best measuring speaker you have seen pre modification. Would it be Magico, Wilson, other???
6.5" woofers all have a peak @ 1 khz. Sour med compared to 3" 4" 5" full range drivers (with a shallow cone). The difference is stark hearing these after hearing 6.5" two ways.
question - don't crossovers in and of themselves cause signals to be out of phase vs the input signal ?
not if designed right
Hi, my 1NT sounds some dull just like sounds blocked by a wall like screen whatever amplifiers are matched. Some dull heavy sound. Any reason you could know how to change? Because I compared with other CDM 1NT users, I could clearly understand mine has some issue with drivers or any. I really love this for many years and want them stay for much longer with me. Thanks.
Hi Danny,
Thanks for the video.
Once more I see that you cross a tweeter an octave lower. Of course this improves vertical dispersion and sometimes frequency response, but I never see you measuring THD/IMD.
I would be very cautious to cross tweeter that much lower. As you know, designing Loudspeakers is a matter of comprises.
Chances are that the modified speakers will sound strained, distorted at high level playback.
In addition, this is a lot more power into the tweeter which might be damaged because of this.
Regarding the tweeter and a crossover over point. How high or low it is crossed is not an issue. I look at the Fs of the tweeter and try to make sure that it is down in output levels at that point. Sometimes I cross the tweeter lower but there is less strain on it than before as the output down low (at its Fs) has been reduced.
Does your "new construction" include an anechoic chamber? I'm assuming the room you are currently testing frequency response in, is inadequate due to your frequency response charts all stopping at 200hz....
We built an anechoic chamber in our first building. It is a big expense, and 99% of what I need to measure I can do outside the chamber using a gated time window.
I’m looking at buying the B&W CM10 any ideas on that model?
Please make a video tour of your facility. Would love to see that
We will do that as soon as we finish up the new remodel.
I had these speakers 20 years ago.
awful sound,very harsh.
I know now why.
You re great ,very professional
B&W are UK’s answer to Bose, it’s all in the marketing! It’s all designed to sound good not accurate.
can you explain why speakers ring? was it the frame with the skinny posts? no! right because its cast. the woofer is kevlar so why would that ring? is being too stiff a problem? ive heard about “proper dampened speakers”. also aware of breakup modes in woofers. thats why you want a stiff speaker. im really interested in this stuff. is it something that is magical? as in, it happens randomly or it doesn’t. like they spent all that money on R&D’ing this woofer that they past the point of no return (starting over). Please answer this in a video. im unaware how to become notified when receiving answers. thanks!
There is quite a bit of ringing in the cone material and it is typical of very stiff cones. A cone material with better damping (like paper) tends to not have as much of a problem. The frame on that woofer rings quite a bit too.
Kevlar like metal cone based drivers have more of a high frequency breakup. That is not to say they are bad just care needs to be taken in the crossover design so their response in that frequency area is minimized.