I used this fabric when I rebuilt my 2+2's:
Mellotone Premium Black Speaker Grill Cloth Yard 64" Wide
It's expensive, but I tried the cheaper stuff only to find out that you could really see through it. I hated seeing the white plastic honeycomb of the panel. YMMV
Mellotone Premium Black Speaker Grill Cloth Yard 64" Wide
It's expensive, but I tried the cheaper stuff only to find out that you could really see through it. I hated seeing the white plastic honeycomb of the panel. YMMV
Acoustat…...Just got my 4th pr of 1+1s....$300.pr with the Medallion interface transformers.....like new......still the best sounding of all..well to my old ears...
I post the money only to show....Big Speakers are Dead to most...an then these 8" tall boys can find a room to day....the Spectra 11-1100 sale $200-250 can give them away....
So now About the Spectra11....the 1100 lowerd the panels down 3-4"
An you see in the pic others lowered them even more.with Z1100
I had about 5 pr of the 11.....never even seen a pr of 1100...funny
The Spectra 11 stock transfourm well not take the full rang...it cook!
Spectra panels can take full rang....
Andy can add his input
Just some info
■Geschichte von ACOUSTAT:
● In 1962,
Jim Strickland established the ACOUSTAT Static Lab.
● In 1964,
ACOUSTAT proposed the technology of using graphite-painted plastic diaphragm to replace the metal diaphragm.
● In 1976,
the 1st static speaker X-type was developed.
● In 1978,
amplifier M-10 of qualifier vacuum tube.
● In 1982,
TNT 200 amplifier and TNP 200 preamplifier.
● In 1984,
1+1 type of products with new design principle were launched into the market and became very popular.
● In 1985,
David Havel, the designer of 1+1, won the prize for the best individual design.
● In 1990,
new products of 1100, 2200, 3300, 4400, and 6600 were launched into the market simultaneously and ACOUSTAT entered the period of maturity.
● In 1993,
to enlarge the manufacture scale, the plant of ACOUSTAT was moved from the United States to Italy, where two factories were set up.
● In 1994,
after the re-location of the ACOUSTAT factories, new products 1200 were launched into the market.
● In 1995,
1300 and 1400 of composite design were launched into the market.
● In 1999,
Asian Static Technology Research Center was established in China, starting the global development of ACOUSTAT.
● In 1999,
ACOUSTAT established branches in Holland.
● In 2001,
the largest static speaker production center was established in China, which was one of the first of its kind entering China after China’s entry into WTO.
● In 2002,
Planning and Promoting Organization of ACOUSTAT (China) was officially established.
● In 2003,
market in China area was developed and products began to be introduced to the United States.
● In 2004,
ACOUSTAT Z22 was awarded the prize of the best flagship.
● In 2005,
ACOUSTAT launched new products: 2005 enhanced version Z1100, Z22, Z2006, Z2008, Z2010, and the biggest Z1 series flagship electrostatic loudspeaker system.
Attachments
![Acoustat1[1].jpg](/community/data/attachments/724/724469-07541e448fd4e39fc31ab57ad57c0171.jpg)
![acoustat-zvocniki-model-z-1100-slika-4064985[1].jpg](/community/data/attachments/724/724471-8bccc3b06099f5aab8fb208573837a5f.jpg)
![Stereo10-2005[1].jpg](/community/data/attachments/724/724473-30b43e7abc8c843c76227b89eb4e040c.jpg)
I improved the bass of my 2+2’s by getting a pair of Boston a400’s
I got a pair of a400’s with new surrounds and refinished cabinets. I replaced the caps in the crossovers and put new ferrofluid in the tweeters. They sound excellent.
But where to put them? I put them next to my 2+2’s and my equipment cabinet.
No, I don’t listen to them at the same time but what I notice is that the bass sounds a bit fuller.
That’s a nice surprise!
I theorize that these speakers, just sitting there not playing, keep the rear bass wave at bay, reducing cancellation. Boston a400 speakers are maybe 5” thick ( real thin) and 4’ tall. For a cone and dome speaker, they are excellent, nice speaker to have if you want something a bit more dynamic than acoustats.
The same effect can be achieve with a plywood sheet or even a piece of cardboard .
As always with room treatment, your mileage may vary...
I got a pair of a400’s with new surrounds and refinished cabinets. I replaced the caps in the crossovers and put new ferrofluid in the tweeters. They sound excellent.
But where to put them? I put them next to my 2+2’s and my equipment cabinet.
No, I don’t listen to them at the same time but what I notice is that the bass sounds a bit fuller.
That’s a nice surprise!
I theorize that these speakers, just sitting there not playing, keep the rear bass wave at bay, reducing cancellation. Boston a400 speakers are maybe 5” thick ( real thin) and 4’ tall. For a cone and dome speaker, they are excellent, nice speaker to have if you want something a bit more dynamic than acoustats.
The same effect can be achieve with a plywood sheet or even a piece of cardboard .
As always with room treatment, your mileage may vary...
OK, I replaced all the components in the bias supply (except the transformer) and directly wired around the damaged area on the PC board. Checked the DC resistance of both transformers (input and output windings) and compared to the good speaker (all fine) and plugged it in. I got 85 VDC at the bias supply.
Installed the interfaces in the speakers and got sound from both. No hum on the repaired speaker. Set them close together and played a mono source and all the sound focused dead center - meaning the speakers (original and repaired) match in output.
Installed back the system and all is well and sounding great.
I suppose I should rebuild the bias supply in the still original speaker but it looked so nice and is working and I did not want to tear into it. I did get enough parts to rebuild this speaker (plus a couple extras) and so I can rebuild whenever needed.
I think I got a little cavalier with these speakers when using my new McIntosh MC 452 (500 Wpc amp) thinking they're old speakers and not worth much and so no big deal. But these are great speakers and it would be difficult to replace them with something new without spending lots of money.
So I will use them a little more carefully.
Anyway, I'm glad I found this forum and thread as it was very helpful for getting the speakers working.
Thanks again!
Excellent job!! 
I love my 2+2's. Wouldn't trade them for anything...Ck the other interface bias,,,,,,if it 80-90 good to go...but if in the lower 70s
this well run the bass transfourmer an res. parts Hoter….an can kill parts...
Just a ward to the wise....good job.....most all the older Acoustat Bias need to re-worket…..
An a new 500mg res well add goodness an better bass, blue wafer type res..seen in the interface pic....Roy E handy worke...small price to pay for a like new ESL speaker.....Long live Acoustats
Attachments
![medallion2[1].jpg](/community/data/attachments/737/737317-e308489f95f7e697c651f759c6217761.jpg)
What's the purpose of the 1/4W resistor and diode attached to the bias supply fuse holder (apparently in line with the secondary 750VAC output)? Does anyone know a source for those 500M resistors?
I just added a stage to my Model 3s' bias supplies and so far no negative effects, but I'm not sure I can perceive an efficiency increase. I did the mod along with replacing all the multiplier caps and diodes, internal wiring upgrades and bypassing the audio fuses and terminal strips and new gold binding posts, so can't be sure what improved the sound, but I do perceive the sound is better at low levels, especially bass weight, almost like a "loudness button" effect from an old receiver.
I just added a stage to my Model 3s' bias supplies and so far no negative effects, but I'm not sure I can perceive an efficiency increase. I did the mod along with replacing all the multiplier caps and diodes, internal wiring upgrades and bypassing the audio fuses and terminal strips and new gold binding posts, so can't be sure what improved the sound, but I do perceive the sound is better at low levels, especially bass weight, almost like a "loudness button" effect from an old receiver.
Those parts are not original. They were added as part of the “Air Mod” to illuminate an LED indicator on the back panel when the HV transformer is receiving power. A few links to discussion of this mod from early in the thread:
Post # 966
Post # 971
Post # 983
Post # 1043
Post # 1048
Post # 1050
The 500M resistor in the picture is an Ohmite thickfilm resistor,SM104035006FE, and can be purchased from Mouser, Newark, Digikey, etc…
https://www.mouser.ca/ProductDetail...=sGAEpiMZZMsPqMdJzcrNwsJljJEG6YukmKHG2ABbTbc=
Those won't work. Spectra speakers need Spectra panels. Spectra panels can be used in non-Spectra speakers, but not the other way around.
The ad states they are SPECTRA panels??? He has some of both. Was there a 3 wire AND a 5 wire non-Spectra panel? He has both of those also.
Here is the list from the ad:
4ea Acoustat 9" panels ....3-5 wire Stock $100ea +packing + shipping
2ea Acoustat 9" Spectra....$150ea +packing + shipping
2ea Acoustat MK121 interfaces $500 for 2ea +packing Shipping
2ea Acoustat MK-121 Medallion Interfaces $699+packing an shipping