Hey Everyone new here. Just posted to the Subwoofer forum and wanted to post here as well because I'm seeing a lot of information on these great speakers.
I own a pair purchased brand new back in 85. (I think it was around 85 anyway my memory is getting bad) Got um from Boulder Sound Gallery in Boulder Colorado if we have anyone from Colorado around might remember. Good old days.
I love these speakers and to my ear they sound as good now as back when I first bought them.
I tried MANY amplifiers and found the best (within my budget) for overall musicality an Audio Research Classic 60 which I've been driving them with for over 20 years or so. I'm in love with the Classic 60 although my second fav. was a Threshold S-300. Drove them louder but just not with that sweet midrange of the tubes.
I use my 2+2's with a pair of subwoofers X-over 120hz 48db I built from Marchand Electronics (XM16)
Anyway at 25 years old I'm looking to perhaps check into new caps & also replacing that wire-resistor for adjusting high frequencies and or anything else I can find here that other 2+2 owners recommend.
I did find a place in az which sells socks. Already got quote for my Ivory ones 180 so I'm going to order those. At first they said they only had black but emailed me later saying they could do the Ivory.
Anyway thanks for listening and any advise much appreciated. Mean while I'll continue searching and reading what I can find.
Mark
I own a pair purchased brand new back in 85. (I think it was around 85 anyway my memory is getting bad) Got um from Boulder Sound Gallery in Boulder Colorado if we have anyone from Colorado around might remember. Good old days.
I love these speakers and to my ear they sound as good now as back when I first bought them.
I tried MANY amplifiers and found the best (within my budget) for overall musicality an Audio Research Classic 60 which I've been driving them with for over 20 years or so. I'm in love with the Classic 60 although my second fav. was a Threshold S-300. Drove them louder but just not with that sweet midrange of the tubes.
I use my 2+2's with a pair of subwoofers X-over 120hz 48db I built from Marchand Electronics (XM16)
Anyway at 25 years old I'm looking to perhaps check into new caps & also replacing that wire-resistor for adjusting high frequencies and or anything else I can find here that other 2+2 owners recommend.
I did find a place in az which sells socks. Already got quote for my Ivory ones 180 so I'm going to order those. At first they said they only had black but emailed me later saying they could do the Ivory.
Anyway thanks for listening and any advise much appreciated. Mean while I'll continue searching and reading what I can find.
Mark
Hey Mark: welcome brother. the only caps you really need to replace are the blue NP electrolytic caps 47 or 50 uf at the input. The plastic caps are fine unless you decide that you want to play with some fancy more expensive ones which is fine but it is nnot a necessity. You might want to swap out the internal wire in the interface if you see that there is any oxide on any of the wire at the connections. Do you have the rotary Ohmite resistor or the brown tubular resistor. The Ohmite is a real keaper but there is nothing wrong with the tubular resistor either. Clean the contact amd put some silicon dielectric gel on it to keep it clean and you are good to go to the grave with your stats.
You might want to try running the HT supply's on some good line filters to keep the line noise of your diaphragms Triplite make nice inexpensive units about $30.00 each for a single duplex design. I hope this is of interest and of some use to you. Best regards Moray James.
You might want to try running the HT supply's on some good line filters to keep the line noise of your diaphragms Triplite make nice inexpensive units about $30.00 each for a single duplex design. I hope this is of interest and of some use to you. Best regards Moray James.
Cool thanks for the info.
I'm not sure which resistors I have I'll have to open and have a look to refresh my memory. I think I remember they are grey with that round ring around them which slides and then tighten with a screw.
I also "think" my MK 121's were the latest they have both the RED and the BLUE update sticker on them.................. I think the store updated them and left which ever sticker was oldest on the case. (Not sure if RED or Blue was newest)
Speakers with a BLUE Medallion label have been upgraded with the Medallion transformers. Although not impossible to upgrade at this point, those transformers are not easy to find.
Speakers with a RED Medallion label have both the improved transformers AND a modification to the high frequency transformer input network. This is fairly easy to do with commonly available parts. If you can't find the "C-MOD" instructions on the Audiocircuit, I can post them here.
By far, the Medallion transformers represent the biggest improvement, although the C-MOD is also worthwhile doing if your speakers don't have it.
I wouldn't bother trying to replace the large gray, 50-watt resistors. Finding resistors of suitable size and wattage will be difficult in any type better than the existing wirewounds. However, there is merit in replacing the electrolytic with a film capacitor (polypropylene etc) in the high frequency input network. If your speaker doesn't have the C-MOD, this would be a good opportunity to make that change too, as the original value of 220-uF will be HUGE to replace with a film type, whereas the C-MOD version uses only 47-uF, which is a much more practical size to replace with a film type.
Concerning the variable resistor for the high frequency balance (whose value also changes in the C-MOD), if you have found your 'sweet spot' for that control, and aren't considering ever changing it, you might want to replace it with two fixed resistors of equivalent value. If you keep the variable resistor, cleaning the contact area and coating with a dielectric grease is recommended, as suggested elsewhere in this thread.
Hey thanks so much this is the info I needed. Let me make sure I understand.
Are you saying the RED sticker means I already have the C MOD? Like I said my units have both the BLUE and RED stickers. I thought they just forgot to remove one when they did the later update but now I see they are seperate updates.
Sounds like if I've got the C Mod I won't have much I need to do. Check into the mentioned caps and possible the two fixed resistors. Yeah I haven't adjusted it in years. Sounds fine where I set it early on.
Thanks to everyone!
Oh, My wife wants me to let her make the socks and save 200 dollars. lol I don't know if she can do it or not. Might have to let her try I think. You know how wifes can be. lol
Your speakers are not supposed to have both Blue and Red labels, but if you have Red labels, it is probably safe to assume you have the C-Mod. More than likely, your speakers were modified twice, once with the Medallion transformers (Blue label) and later with the C-Mod (Red label). Evidently whoever did the second modification didn't remove the Blue labels. To be absolutely sure, look at the electrolytic capacitor in the HF filter - if it is 47-uF, then you have the C-Mod. If it is 220-uF, it is not C-Mod.
Changing the 47-uF capacitor to a film-type is the only upgrade that I would recommend for your interfaces. Changing the variable HF Balance control to two fixed-value resistors should be done only if you are sure you'll never want to change the HF balance.
If you elect to make your own grille socks, I would suggest you start by making a short tube of fabric to test its stretchiness, before commiting to a piece of fabric as large as the speaker. The original Acoustat fabric had quite a bit of stretch to it, so the diameter of the fabric tube, as sown, was smaller than the circumference of the speaker.
FYI, the original Acoustat grille cloth is a double-knit, which does a good job of hiding the ugly innards of the speaker. However, it is not the best at sonic transparency. Using a more shear fabric (i.e. single knit) will likely yield better sound, but will not hide the panels as well. Ah, life is full of trade-offs, eh? (Meaning you should discuss this aspect with your mate, in case cosmetics are an over-riding factor.)
If you elect to make your own grille socks, I would suggest you start by making a short tube of fabric to test its stretchiness, before commiting to a piece of fabric as large as the speaker. The original Acoustat fabric had quite a bit of stretch to it, so the diameter of the fabric tube, as sown, was smaller than the circumference of the speaker.
FYI, the original Acoustat grille cloth is a double-knit, which does a good job of hiding the ugly innards of the speaker. However, it is not the best at sonic transparency. Using a more shear fabric (i.e. single knit) will likely yield better sound, but will not hide the panels as well. Ah, life is full of trade-offs, eh? (Meaning you should discuss this aspect with your mate, in case cosmetics are an over-riding factor.)
When I made my Spandex socks I ended up with the fabric being half the circumference of the speaker, so it ended up being stretched to twice its size. This yields a semi-transparent look where you can just make out the grids of the panels if you look closely. Under normal viewing they just look like blue monoliths. They are far more acoustically open than the stock socks, though; the highs are much clearer this way. I'd never consider going back to the old socks, both in looks and sound.
Your speakers are not supposed to have both Blue and Red labels, but if you have Red labels, it is probably safe to assume you have the C-Mod. More than likely, your speakers were modified twice, once with the Medallion transformers (Blue label) and later with the C-Mod (Red label). Evidently whoever did the second modification didn't remove the Blue labels. To be absolutely sure, look at the electrolytic capacitor in the HF filter - if it is 47-uF, then you have the C-Mod. If it is 220-uF, it is not C-Mod.
Changing the 47-uF capacitor to a film-type is the only upgrade that I would recommend for your interfaces. Changing the variable HF Balance control to two fixed-value resistors should be done only if you are sure you'll never want to change the HF balance.
If you elect to make your own grille socks, I would suggest you start by making a short tube of fabric to test its stretchiness, before commiting to a piece of fabric as large as the speaker. The original Acoustat fabric had quite a bit of stretch to it, so the diameter of the fabric tube, as sown, was smaller than the circumference of the speaker.
FYI, the original Acoustat grille cloth is a double-knit, which does a good job of hiding the ugly innards of the speaker. However, it is not the best at sonic transparency. Using a more shear fabric (i.e. single knit) will likely yield better sound, but will not hide the panels as well. Ah, life is full of trade-offs, eh? (Meaning you should discuss this aspect with your mate, in case cosmetics are an over-riding factor.)
Thanks so much for the info!
I opened the transformers to have a look at it's got a white 47uf "Wonder Cap" with two more bypass caps across it. One medium size and one smaller one. Sounds like I'm updated unless anyone things the wonder cap needs changed.
I don't have much room to work around them because my wife has a TON of plants around them. I'm going to go for it this summer when she moves some of the plants outside. At that time I'll change the cloth and possibly check the power suppy caps someone mentioned in the other thread as well as think about either leaving or replaceing that sliding resistor.
Honestly though I think these still sound as good as the day I bought them. Figure with a few updates they will last another 25 years. Out live me.
There was no business relationship between Acoustat and Wondercap. Wondercaps were never used in any factory installations. If you encounter them in an interface, they were most certainly changed at a later time.
Ok I was remembering back and I remembered Boulder Sound Gallery where I bought them put the wondercaps. I remember them asking me if I wanted them to do a minor upgrade bypassing caps. It actually has three caps: The larger wonder cap with a middle size cap across it and then a pretty small one across both of those.
But yes it was the store where I bought them new that did this I remember going for it because they hardly charged me much for it.
Wife's moving the plants outta the way so I'm gonna get in there and do some up grades real soon. Socks are the first thing have to go.
I really thought long and hard about just selling them and go for something new but I'm a believer in running full range from at "LEAST" 200 hz up. Keeping crossovers/phase shifts and all out of critical range. After 26 years these speakers still sound STUNNING so honestly it would be stupid for me to get rid of them.
I'm thinking of raising up my Subwoofer crossover from 100 to maybe around 160hz (3rd octave) if anyone has any thoughts on that? I use a 48db crossover and a very fast woofer (4 Dynaudio 30W100's) so it might work. My thoughts are just to try and limit a little more work from the aging 2 plus 2's.
Thanks for everyones helpful ideas!
Mark
Ok all I've done so far is change the socks so I'm ready to make some further changes and have a couple of questions.
My left speaker has developed a very low level "snap" that occurs regularly about once every minute. I assume this is some kind of discharge. Speaker still sounds fine and you can't even hear it unless your close to the speaker.
It's making me think that after 26 years plus the panels are probably pretty dirty due to electrostatic charge attracting dust particals. I know the cloth covers were super dirty.
Someone in another Acoustat thread mentioned taking the panels out and washing them in the tub with some mild degreaser keeping the panels on edge to prevent pressure to the panel. Is this advisable? If so are the panels with the wiring hard to remove and reassemble? Off hand I can't think of an easier way to try to clean them.
Moray I saw you supplied the power supply caps and diodes to someone else do you still supply these? I'm thinking it sounds like a good idea to change mine as the caps may be degrading with age. Another thing could I add another step up stage to increase the voltage a bit? Would like to do this as well.
As far as I can tell my C-Mod is fine and should not need changing. I think I'm also ok with the grey slider resistor.
I do want to change the cheap-o binding posts they put on. That looks like it should be easy as I change a pair on one of my power amps recently without issue.
As always thanks for everyones help and opinions! At 26 years old these speakers still sound great to me and I think I'd have to spend an awful lot to do better. There for I think it's well worth spending a little to upgrade them.
Oh, I tried raising the subwoofer crossover to 200 hz but it doesn't sound right. Lowered that back down again. The 2+2's bass is I think good enough over 100hz.
Mark
My left speaker has developed a very low level "snap" that occurs regularly about once every minute. I assume this is some kind of discharge. Speaker still sounds fine and you can't even hear it unless your close to the speaker.
It's making me think that after 26 years plus the panels are probably pretty dirty due to electrostatic charge attracting dust particals. I know the cloth covers were super dirty.
Someone in another Acoustat thread mentioned taking the panels out and washing them in the tub with some mild degreaser keeping the panels on edge to prevent pressure to the panel. Is this advisable? If so are the panels with the wiring hard to remove and reassemble? Off hand I can't think of an easier way to try to clean them.
Moray I saw you supplied the power supply caps and diodes to someone else do you still supply these? I'm thinking it sounds like a good idea to change mine as the caps may be degrading with age. Another thing could I add another step up stage to increase the voltage a bit? Would like to do this as well.
As far as I can tell my C-Mod is fine and should not need changing. I think I'm also ok with the grey slider resistor.
I do want to change the cheap-o binding posts they put on. That looks like it should be easy as I change a pair on one of my power amps recently without issue.
As always thanks for everyones help and opinions! At 26 years old these speakers still sound great to me and I think I'd have to spend an awful lot to do better. There for I think it's well worth spending a little to upgrade them.
Oh, I tried raising the subwoofer crossover to 200 hz but it doesn't sound right. Lowered that back down again. The 2+2's bass is I think good enough over 100hz.
Mark
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Hi, Mark.
I am waiting for the results of giving your panels a bath before trying the same on mine. I hope that the panels easy to remove and put back.
What did you use for new socks? The Upholstery Company in Arizona told me that they did not sell beige/white socks for 2+2s any more.
I have a pair of 2+2s I bought recently from the executor of an estate sale. One speaker has snapping noises every few seconds. I hear the snapping from 15 feet away. The sock was faded and very dusty on this speaker. The other speaker, which does not snap at all, has a much cleaner sock. With a flashlight, i saw many pinholes in the diaphragm of the upper panels of the noisy speaker, but aside for the snapping noises, that speaker sounds as good as the quiet one.
The original owner lived in the desert and had the speakers near a sliding glass door for 20 years, which would account for the dust and fading. The 2+2s were powered by a pair of Acoustat TNT200 amps, and were actually the rear speakers in a surround sound system. He had Acoustat 6s for front speakers, which were powered by a pair of Hafler 9505 amps in his 35x20' listening room. The executor of the estate told me that, since his friend's closest neighbors lived a quarter mile away, he played jazz as loud as he wanted on his stereo often in the middle of the night.
I am waiting for the results of giving your panels a bath before trying the same on mine. I hope that the panels easy to remove and put back.
What did you use for new socks? The Upholstery Company in Arizona told me that they did not sell beige/white socks for 2+2s any more.
I have a pair of 2+2s I bought recently from the executor of an estate sale. One speaker has snapping noises every few seconds. I hear the snapping from 15 feet away. The sock was faded and very dusty on this speaker. The other speaker, which does not snap at all, has a much cleaner sock. With a flashlight, i saw many pinholes in the diaphragm of the upper panels of the noisy speaker, but aside for the snapping noises, that speaker sounds as good as the quiet one.
The original owner lived in the desert and had the speakers near a sliding glass door for 20 years, which would account for the dust and fading. The 2+2s were powered by a pair of Acoustat TNT200 amps, and were actually the rear speakers in a surround sound system. He had Acoustat 6s for front speakers, which were powered by a pair of Hafler 9505 amps in his 35x20' listening room. The executor of the estate told me that, since his friend's closest neighbors lived a quarter mile away, he played jazz as loud as he wanted on his stereo often in the middle of the night.
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Well I'm going to wait to hear some of the experts opinion before I attempt to take mine apart and wash them. I'm thinking that's the only way to clean them good and I'm pretty sure it's micro-dust on the panels that's causing the discharges.
You don't have pin-holes in your panels. What looks like holes are really just pin size spots where the coating came off or wasn't coated properly. At least that's what I've read here.
I never liked the Acoustat TNT-200. Friend of mine blew his up driving his 2+2's and my little Audio Research Classic 60 tube amp made the TNT-200 sound awful by comparison.
Mark
You don't have pin-holes in your panels. What looks like holes are really just pin size spots where the coating came off or wasn't coated properly. At least that's what I've read here.
I never liked the Acoustat TNT-200. Friend of mine blew his up driving his 2+2's and my little Audio Research Classic 60 tube amp made the TNT-200 sound awful by comparison.
Mark
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