ADS M12 speakers

[CorvetteXZR1]

a/d/s/ M12/90 crossover

I just came across this thread under a google search for a/d/s/ M12 speakers. I own a set of M15s (same thing except with 10 inch woofers for better low end response) and over time realized the bass lacked extension pretty badly. I changed out the crossovers for the newer M15/90 crossover which has two separate boards that mount in both the bottom two sections of the cabinet. The bottom board has two transformers and the top board is the crossover for the midrange and tweeter. The M15/90 is indeed a much better crossover.

With the new crossover, the speaker as a whole had less distortion in the midrange, highs and lows. With bi-wiring or Bi amping the sound was also much cleaner all around especially in the bass. With the minimized distortion the speakers were much smoother sounding, more transparent and imaged better. If you can get your hands on a nice original pair of M12/90 or M15/90s I would definitely recommend them. If you are able to buy a M15/90 crossover, I would also recommend swapping them out.

 

[MJB1959]

Good read, I have owned a pair of M12's for a few years, I also have the L880's and L620's by ADS. I have had the L810's as well, hopefully to get another pair someday. I felt the same way about these M12's especially when paired with and against the L880, very different animals. I am driving them with an NAD 3150, for some reason, when I listen to the M12's alone, and adjust the bass up a few notches, I really like their overall sound, very distinct, and clear. Whereas with the L 880, I need to temper the bass down a bit, as they have a tendency to boom a bit with lower frequencies.
I had previously hooked the M12's to my Yamaha CR 2040, and they seemed to really lack in the low end, That "natural sound" of the Yamaha is very uncolored naked sounding. and the NAD seems to give them the extra something they need.

I am considering the new NAD 375BEE or the Peachtree Decco as a newer replacement amp, as I have gotten persmission from the Mrs, to continue with my hobby.

 

[sb001]

Hi all- I came across this old thread for the a/d/s/ M12 speakers and thought I would put in my 2 cents worth-
I recently acquired a pair of these M12s with the same kind of woofer distortion others have been talking about on this thread, all except one were distorting regardless of volume like there was a voice coil problem or something. I found this thread and saw where it said the inductors on the crossovers could be at fault- so I started to go that route, but then I noticed that if I put my finger on a certain section of the woofer surround, the buzzing/ popping distortion went away and the woofer acted completely normal! Then I noticed the same thing to a lesser degree on the mids as well. I noticed that the surrounds on these drivers have a sort of raised edge that they adhere to, and so I started wondering if the surround was getting pulled away from the edge from use over time. So I got some electric tape and put a stretch of tape straight across the corners where touching the surrounds stopped the distortion- and what do you know, the distortion is completely gone!
Posted some pics below-- ugly as hell and not planning on leaving it like that but it solved the distortion problem!
So assuming the surround really is the problem, is there a permanent fix for this??

 

[Lloyd Foster]

I have owned a pair of M12 speakers for two years and have used in my main system for about half that time. I have some experience building speakers and re-building crossovers and at their age, I thought new electrolytic caps would be in order because they get resistive as they age. I pulled out the x-overs, made note of the parts values and replaced all but one or two caps because I could not find a direct value replacement. More importantly: I upgraded all the resistors to non magnetic wire wound and replaced the four film caps with Solens.
I didn't touch the copper inductors. My M12s have plenty of bass to my ears using a Mcintosh 4275 receiver with the controls flat. If I wanted to boost the bass without controls, I would use an inductor with less DC resistance. In my experience, the best would be those from North Creek Music. They are not inexpensive but even the 14 gauge would add a lot of bass information and the larger gauge would produce staggering amounts of bass. You would have to improvise a way to mount them but there is plenty of real estate in that compartment.
My recommendation would be to replace the parts as I have done which could be considered maintenance and a little upgrade and if after that you still feel the bass is shy, consider new copper inductors for the lower x-over circuit.
Good luck!

 

[virii01]

Hi all- I came across this old thread for the a/d/s/ M12 speakers and thought I would put in my 2 cents worth-
I recently acquired a pair of these M12s with the same kind of woofer distortion others have been talking about on this thread, all except one were distorting regardless of volume like there was a voice coil problem or something. I found this thread and saw where it said the inductors on the crossovers could be at fault- so I started to go that route, but then I noticed that if I put my finger on a certain section of the woofer surround, the buzzing/ popping distortion went away and the woofer acted completely normal! Then I noticed the same thing to a lesser degree on the mids as well. I noticed that the surrounds on these drivers have a sort of raised edge that they adhere to, and so I started wondering if the surround was getting pulled away from the edge from use over time. So I got some electric tape and put a stretch of tape straight across the corners where touching the surrounds stopped the distortion- and what do you know, the distortion is completely gone!
Posted some pics below-- ugly as hell and not planning on leaving it like that but it solved the distortion problem!
So assuming the surround really is the problem, is there a permanent fix for this??

Sounds like it could be voice coil rub. The parts sag with gravity over time. You could try taking the speaker out and rotating it 180 degrees. If that doesn't work you could send the drivers in to Richard So @ ADS Speaker Service.

 

[jsimone]

Original owner for 25 years

The a/d/s M12 has absolutely been a wonderful speaker system for me. I originally purchased a pair of M12s back in 1990. However, after 25 years materials break down - even for very well kept speakers. Things such as:

• glues in the drivers break down causing the spider to detach
• steel baskets rust and the rust falls into the magnetic voice coil gap impeding its motion
• ferro fluid in the midrange and tweeter dries and is either sticky or hard
• the rubber surround material gets hard or cracks
• the walnut veneer oxidizes and dries

The speakers played fine BUT they had lost that sparkle, brilliance and crispness from days gone by. So what to do about these issues?

I undertook a project to restore the speakers to their original condition. I lightly sanded the veneers using a sanding block (one direction only consistent with wood grain) with 200, then 400 and finally 600 grit sand paper and then applied about 6 coats of WATCO Danish oil finish (natural). This brought out the beauty, color and grain of the natural walnut. Between each application I let dry for 3-4 days (sometimes longer).

I next attempted to replace the ferro fluid (purchased from parts express) in the tweeters . Upon cleaning and inspecting the magnetic gap and the tweeters themselves - the dome cracked in my hand - it was very brittle.

I decided to ship the tweeters to Richard So and have him rebuild them for me (ref: http://www.adsspeakersservice.com/ ). When the tweeters came back they sounded so awesome - crisp and clean highs - that I decided to send the midranges to Richard for rebuild. He noted rust from the steel basket had fallen into the magnetic voice coil gap and one of the spiders was loose in addition to the surrounds rubber being hard. Well those came back and they sounded fantastic - I had not heard new midranges in 25 years. Finally the woofers were rebuilt.

Note: all 4 woofers looked fine and sounded fine - but they were not. The rubber surrounds had hardened (stiffening the free movement). I bit the bullet and sent all 4 woofers to Richard's electronics shop in Arizona. I just got them back and installed them last night. Wow! What a difference in sound quality now.

After about half-a-year of sanding, finishing and rebuilding the project is done and the speakers look well ... new. More importantly the speakers sound new.

Richard So is an amazing expert in this area and he devotes exceptional care and handling and finally in testing (a frequency sweep to check for rattles/buzzing etc) to the drivers he rebuilds. He has been the goto guy for restoring my a/d/s M12 system back to its former grandeur.

Finally, after visiting several audio shops located near me listening to new speakers: Klipsch, Energy, Magnepans and others - maybe the M12s are not better BUT and this is a big BUT they do hold their own for a fraction of the price of new speakers.

If you are fortunate enough to find these speakers - GRAB THEM. You won't be sorry. They are awesome - especially when restored to new condition.

Cheers

P.S. I have not applied the inductor fix to the crossover. They sound amazing as is.

 

[seb9316]

You must paid close to $800 to restore those (yes Richard So does great work but his prices are not inexpensive.) Not worth it IMO, especially when the L-1290s that don't seem to have near the problems can be found for half that.

 

[virii01]

They're worth whatever he values them at. Enjoy, I bet they look and sound great. Post some pics.

 

[seb9316]

They're worth whatever he values them at.

No, they aren't. This is the most overused line on this board. My favorite speakers of all time are the L-1290s and I'd love to have a pair, but I value them right at their going rate, $400-$500, or less if I can find them for less.

 

[virii01]

He's not asking for what he should list them on barter town so yeah, they're worth whatever he values them at. No need to thread crap on a guys post about how he's happy with what he has.

 

[Jelle]

I love posts on restorations of good gear. Like the one Jsimone just posted.

Self restored gear is priceless.

 

[240sx4u]

I have a pair of M12s as well. My only complaint which was easily solvable (multiple subs) is the lack of low bass. I just moved them into my main system for a temporary stint while I finish my DIY jobbers and man these are good sounding speakers. So much better than I had expected. They were for sale at one point which is no longer the case.

 

[teebee]

It seems to me that many of the poly cone ADS (Sat, CM, M, AW, and other '90s variants)have somewhat plasticizing rubber surrounds that stiffen and develop a memory. Has anyone experienced this? The damping is excellent, but fs is raised somewhat.

Rotate woofer, yes. You can kind of feel where the woofer is more prone to rubbing. The cone is heavier at the coil end than the outer edge and the spiders are very compliant.

 

[jdurbin1]

Haven't seen any issues with surrounds at all but I mostly own either older models with butyl surrounds or newer ones (HT-series for instance).

I have run into the sag/rotate issue a couple of times, also the notorious frame rot.

But, overall these speakers hold up WAY better over time than the vast majority of other stuff I've seen.

John

 

[soundmotor]

It seems to me that many of the poly cone ADS (Sat, CM, M, AW, and other '90s variants)have somewhat plasticizing rubber surrounds that stiffen and develop a memory. Has anyone experienced this? The damping is excellent, but fs is raised somewhat.

The original CM & M had vinyl-damped surrounds and were failing while I still worked there in the late 80s. They were purged and never used again. Easy to spot, they are hard and whitish (over gray). There is no fix except to replace the surrounds. The SAT, AW, and all other models used normal surrounds. This included service replacement drivers for the early CM & M.

 

[teebee]

The original CM & M had vinyl-damped surrounds and were failing while I still worked there in the late 80s. They were purged and never used again. Easy to spot, they are hard and whitish (over gray). There is no fix except to replace the surrounds. The SAT, AW, and all other models used normal surrounds. This included service replacement drivers for the early CM & M.

So glad you are here, Soundmotor. You rock. Thanks!

 

[jsimone]

The original CM & M had vinyl-damped surrounds and were failing while I still worked there in the late 80s. They were purged and never used again. Easy to spot, they are hard and whitish (over gray). There is no fix except to replace the surrounds. The SAT, AW, and all other models used normal surrounds. This included service replacement drivers for the early CM & M.

That is correct according to Richard So, who repaired my drivers. He said the original surrounds were faulty and a/d/s later replaced them with surrounds made of more pliant rubber.

The difference in sounds output is considerable. The drivers, especially the woofers, really move freely now.

I was debating whether to fix them or sell them. After listening to new speakers in the $1k each price range - I decided just to rebuild the drivers and enjoy the result. Most, if not all, speakers made today are made in China. The a/d/s M12s were made in the good old USA! I am ok with that.

By the way - there is a pair for sale on ebay. Seller originally wanted $1500 for the pair. There were no takers at $1500. He is on his 2nd relisting at $995. I would assume if all the drivers are original then that pair would have the same issues Richard saw in my drivers: rusty baskets, rust fallen into voice coil, stiff surrounds, dry/fragile/cracked tweeters and lastly dry/sticky ferrofluid. Nothing lasts forever - but not too bad for 25 years of rockin' use.

Cheers.

 

[district644]

Hello all

I have owned a pair of the M-12's for 12 yrs and have not had any of the above issues. I am the second owner which makes me wonder if there was a switch in the parts maker at some point or another. The only thing I've been interested in doing is a recap and update the crossover but they sound wonderful still. I had also thought if they could possibly be biamped. If I'm not mistaken I thought I've read the M-12/90 were.

 

[Dameatrice]

I was lucky enough to find a pair of M12 at the thrift store a month ago. Paid 12.99 for the pair. In beautiful condition I read about the inductor problem. I only paid 12.99 so what the hell. I recieved the inductors today and installed them and OMG. These are truly keepers.

 

[Blue Shadow]

I recieved the inductors today and installed them and OMG. These are truly keepers.

This post deserves its very own thread. You get some speakers cheap and them fix em up nice and just put a tag on the end of a thread, lost to the masses. How about a whole thread on what you got what you did and why along with that glowing review at the end. I'm sure there are folks looking for that kind of information.