If you want to consider something beyond the basic black or white, try these guys:
Acoustone Fabrics for Sound. Improve Quality of Sound When Covering Speakers or Surfaces.
I used them years ago to cover Quad ESL-63's with great results.
Acoustone Fabrics for Sound. Improve Quality of Sound When Covering Speakers or Surfaces.
I used them years ago to cover Quad ESL-63's with great results.
The company, (The Upholstery Company of Arizona – 418 N Hunt Dr, Mesa, AZ) that actually made those for Acoustat, no longer makes them. You will have to find the fabric and have a local seamstress make them.
This is the fabric I used:
Mellotone Premium Black Speaker Grill Cloth Yard 64" Wide
It's expensive and you'll need 6 linear yards. I tried a couple of the cheaper options, but absolutely did not like the see through nature. You can see the plastic frame grid. The ones above are thicker and work perfectly.
I'm sure there will be others who claim that they interfere with the acoustics, but I found that to be total hog wash. I've tried them naked and with several different thicknesses and found no difference in sound. YMMV.
This is the fabric I used:
Mellotone Premium Black Speaker Grill Cloth Yard 64" Wide
It's expensive and you'll need 6 linear yards. I tried a couple of the cheaper options, but absolutely did not like the see through nature. You can see the plastic frame grid. The ones above are thicker and work perfectly.
I'm sure there will be others who claim that they interfere with the acoustics, but I found that to be total hog wash. I've tried them naked and with several different thicknesses and found no difference in sound. YMMV.
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I just covered my DIY 0.88+0.88s (1+1s using 8" panels) with Matte Milliskin spandex: You are being redirected... and it looks and sounds great. I stretched it about 65% in the horizontal direction and just slightly in the vertical and it's quite opaque to light. I expected it to be more see-through.
Need some help please..
HI All,
I recently bought a pair of Acoustat 2+2's. They've been in storage for many years and need some tiding up.
I'm looking forward to powering them up. Speaking off, I removed the power supplies (121-B) to repaint and check over and found one power unit has a broken tab coming off the red lug socket going to the board. Does anyone know where I could find a replacement socket? 🙂 I've tried googling but come up empty. Any help would be much appreciated.
HI All,
I recently bought a pair of Acoustat 2+2's. They've been in storage for many years and need some tiding up. I'm looking forward to powering them up. Speaking off, I removed the power supplies (121-B) to repaint and check over and found one power unit has a broken tab coming off the red lug socket going to the board. Does anyone know where I could find a replacement socket? 🙂 I've tried googling but come up empty. Any help would be much appreciated.
I have used these Keystone jacks and tip-plugs for Acoustat repairs.
Keystone pn 6055:
6055 Keystone Electronics | Mouser
Keystone pn 1601:
1601 Keystone Electronics | Mouser
Keystone pn 6055:
6055 Keystone Electronics | Mouser
Keystone pn 1601:
1601 Keystone Electronics | Mouser
Much thanks bolserst. Looks like that will work nicely. Its been many years since I had a set and I still remember the wonderful sound.
One other question, I thought to power up the power supplies via a variac to wake them up slowly after their long sleep.
Do I need to have the panels connected to do this or not.
Cheers
Do I need to have the panels connected to do this or not.
Cheers
It's not necessary to connect the panels, but unless you have a high-voltage probe, you'll have no way to verify if the bias supply is working if you don't have panels connected.
I don't see a great need to use a Variac to slowly increase the voltage. The power supply contains no electrolytic capacitors that would need to reform, as would be the case for other electronics.
My advice would be to connect the panels, apply AC power, charge 'em up for a few minutes, and play music to verify operation.
I don't see a great need to use a Variac to slowly increase the voltage. The power supply contains no electrolytic capacitors that would need to reform, as would be the case for other electronics.
My advice would be to connect the panels, apply AC power, charge 'em up for a few minutes, and play music to verify operation.
Thank you very much AcoustatAnswerMan for your advice. I’ll replace the broken red socket, connect the panels, power up an cross my fingers for music. Much thanks again for your help guys.
3 Wire Panels
Hi Acoustatanswerman,
Can 3wire panels be converted to 5wire panels?
Regards
Cleaton
Hi Acoustatanswerman,
Can 3wire panels be converted to 5wire panels?
Regards
Cleaton
I converted 3-wire to 5-wire panels quite easily by picking out the end of the wire from the panel which gave about an inch to attach an extra wire to. Of course you won't get the benefits of the improved coating that came with the real 5-wire panels.
Series input configured
I had one pair of 1+1, anybody try series the input transformers and take out the one ohm resistor. Can this change make the speaker a little bit louder?
I had measured the high voltage before the 500Mohm resistor with HV probe and get 4300V, is this normal. Thanks.
I had one pair of 1+1, anybody try series the input transformers and take out the one ohm resistor. Can this change make the speaker a little bit louder?
I had measured the high voltage before the 500Mohm resistor with HV probe and get 4300V, is this normal. Thanks.
Attachments
Your bias voltage measurement is within expectations. High Voltage probes tend to load the supply, so you’ll never read the full 5000 VDC.
Removing the 1-ohm resistor in series with the LF transformer will not make the speaker play louder. It is there as a safety measure, since most amplifiers don’t like the speaker’s very low impedance at low frequencies. The 1-ohm resistor keeps that impedance above a practical limit.
Placing the transformers in series will not make the speaker play louder. In fact, it will pretty much ruin the entire speaker’s performance. This is a very bad idea.
Keep in mind that the 1+1 has limited panel area and is not designed to fill even medium-sized rooms with concert hall levels. I don’t know what amplification you are using, but it may be that you have reached the speaker’s inherent limit.
Removing the 1-ohm resistor in series with the LF transformer will not make the speaker play louder. It is there as a safety measure, since most amplifiers don’t like the speaker’s very low impedance at low frequencies. The 1-ohm resistor keeps that impedance above a practical limit.
Placing the transformers in series will not make the speaker play louder. In fact, it will pretty much ruin the entire speaker’s performance. This is a very bad idea.
Keep in mind that the 1+1 has limited panel area and is not designed to fill even medium-sized rooms with concert hall levels. I don’t know what amplification you are using, but it may be that you have reached the speaker’s inherent limit.
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A point of clarification: the 5-wire panels were introduced before the new coating was introduced. Therefore, not all 5-wire panels have the improved coating. The only sure way to identify the new coating is if the bias wire is yellow with a red stripe.
As mentioned in a previous post, yes. But it's a very tedious and difficult process task, and can easily lead to a ruined panel. In my opinion, it's not worth the trouble.
I wouldn't bother with the 3 to 5-wire conversion if I didn't have my speakers apart already, but it's not that hard to do IMO, and it probably yields most of the benefit of soldering across all the loops on each end with about one hundredth the labour required. 10 kV wire is readily obtainable on Amazon and it ships about ten times faster than they claim at the cheapest shipping option.
Thank you Acoustat Answer Man.
I used dynaco st70 but modify to delivery 55 watt instead of the original 35 watt output.
I used dynaco st70 but modify to delivery 55 watt instead of the original 35 watt output.
I added an extra "rung" to the bias supply on my 0.88+0.88s (DIY 1+1s with 8" panels) and powered by an NAD C275BEE it goes way louder than I need to listen in an 11' by 12' room. The bass is unbelievably strong and I wouldn't even consider the addition of a sub-woofer. The NAD can deliver 600 watts into 2 ohms dynamically but is rated 150 into 8.
55 WPC won't allow the 1+1s to deliver their loudest performance. These are power-hungry speakers, and 200-250 WPC is not unreasonable to wring those last few dB from the speaker.
I have an issue with some spectra 11's. They are the later version with the wall wart. I can't seem to get the bias voltage high enough. with the pots maxed out on both speakers, The left maxes out at 35v the other at 52 volts. I would really like to get them up to the recommended 75v. I heard that going beyond that should act as an improvement as well.
I also read that upgrading the power supply caps to a larger size (the 47uf and 470uf) is a good idea.
Where should I start with getting the bias to where it needs to be? Replace diodes, 47uf and 470uf caps and the 3300pf caps? I assume it is time to replace them anyways.
Thanks!
I also read that upgrading the power supply caps to a larger size (the 47uf and 470uf) is a good idea.
Where should I start with getting the bias to where it needs to be? Replace diodes, 47uf and 470uf caps and the 3300pf caps? I assume it is time to replace them anyways.
Thanks!