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Old 20th January 2006, 05:13 PM   #1
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Angry Acoustat arcing problems

I have been using a pair of Acoustat model 2 speakers for about 25 years, when I purchased them new. Recently I purchased a pair of 1 + 1s, but I am having some problems with them.

At first they worked OK, but after they had had a chance to charge up for a few days, one panel began making popping arcing sounds, about once per second even when no music is being played. eek: I also noticed that on moderately loud music that all of the panels make these sounds, some more, some less. As well, when you lightly tap the speakers with your finger they also make these snapping, arcing sounds. In fact, even the quiet little turn-on thump of my amplifier causes both speakers to go SNAP! as well.

With my original model 2s, the only time you can hear any arcing sounds at all is when you turn them up VERY loud, obviously overdriving the panels. These 1 + 1s do it all the time, even at lower volumes! As well, there is a resonant vibration in the one of the panels, it rattles when certain frequencies are present in the music.

When I first lowered the grill socks from the speakers, I found all of the felt damping pads had fallen off of the back of the panels in one speaker. When I looked at the actual membranes by shining a flashlight through them, I found that they are literally full of thousands of small holes, and some as big as 2 or 3 mm in diameter.

The seller stated thet these speaker were in good working condition before the sale, and does not believe me when I tell him that they are damaged. At most he thinks they were damaged in shipping, which I feel is very unlikely.

Does anyone think that this might be shipping damage? Does massively overdriving Acoustats cause them to fail this way? I have carefully vacuumed the panels with no effect, I also tried the hairdryer trick, but this did not help either. Many people say that acoustat panels can not be repaired, other say they have opened them up and done so. I may eventually try to repair these panels, but at the moment it looks like I am on the hook for 4 new panels from wherever I can find them, unless I just swap in the panels from my model 2s. However, the wires are shorter on the model 2 panels as the speaker is much shorter, so I would have to extend their wires, including insulation to above 5KV.

Can anyone offer and help or suggestions??

Take care,
Doug:
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Old 20th January 2006, 05:55 PM   #2
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Default old panels

Doug: the small pin holes are not unusual for old Acoustats I have seen holes up to and past 1/2 inch but usually they are just pin size. The holes in no way impact on the performance or sound of the panels so you can put that worry out of your mind. It is possible that the panel's stator wires have at places come loose. That can cause noise and arcing. You can inspect the stators and find any loose stator wires. When you find them you can use twist ties to pull them back up into place and glue them with airplane model glue. This is a slow and fussy process but it works. There is a discussion at the Audio Circuit by Andy Zasbo about the popping issue so you can read that. Your best bet is to build yourself a new set of panels. If you want we can arrange to meet and I can show you the jigs I have for winding stators and what is involved in building new panels. Remember that once you have a good arc that burns or punches a hole through the pvc dielectric (as a result of breaking loose off the louvre and hanging too close to the diaphragm) you cannot fix that arc hole. So if there are a bunch of those you might just as well start fresh. Shipping can cause older panels to have a lot of wires pop loose out of place. Most ESL owners with such problems realize that the trouble began either after a move or bringing the speakers out of a prolonged storage.
If you want to swap out your working panels you can extend the connection wires with similar PVC insulated wire. Stager the splices by an inch or so and use standard shrink wrap you won't have any troubles. Rebuilding your existing panels can be done (I have done so) but I can tell you that it is much more work than to build new panels. Further a rebuilt set will still have arcing problems as the stator wire dielectric is full of holes that you cannot fix. New panels will not arc and will be superiour to the factory units in every way. Regards Moray James.
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Old 20th January 2006, 08:36 PM   #3
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Thank you for your informative reply. A few more questions:

-How much do you estimate the cost per panel would be if I built 4 new panels?

-Approximately how long does it take to actually construct one?

-Would you be willing to construct new panels for me (I know, I know, this is DIY, but I just don't have much time for even MORE new projects) and how much would they cost me?

Thanks again!

Take care,
Doug
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Old 20th January 2006, 11:56 PM   #4
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Doug: I just don't have the time to build you new panels but I might be able to get one of my buddies to build them for you. As to cost that would be between the two of you. That said I would be happy to let you use the jigs that I have but we will have to do some foot work to work it all out. As to cost that will depend on you mostly. If you want to use styrene louvre that is about 10 bucks for a 4X2 foot sheet so $40.00 in louvre. If you want to use acrylic louvre then it is about $20.00 per sheet. Then you will need spacer material @ about $20.00 and wire. I would suggest double build magnet wire with a gage of 30. A spool of that will run around $35.00 or so. Then you will need solvent adhesive at around$40-50.00. Diaphragm material is cheap but Licron will cost you about $75.00 for a large spray can. These are all Canadian dollars . That is probably the lions share right there so you can do the math. If you want to use acrylic transfer to assemble then you will have to check with local suppliers for the cost of that as it is spendy in small quantities. i would recommend LePages press tight green contact adhesive which goes for about $20.00 per litre. Probably figure in $50-75 for incidental and screwed up bits and pieces and that ought to cover all of your materials.
The first one will take the longest time after that they will go faster. You are probably looking at a couple of weekends perhaps less.
If you are not in a hell fire hurry I have a buddy who is in the process of building four new panels and if the switch over could be worked out between the two of you he would probably be happy to sell you his Acoustat panels once the new ones are built. You would be able to listen to the current panels and evaluat thier condition. They sound just fine. Send me a PM and we can discuss this all further. Best regards Moray James.
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Old 26th August 2010, 08:16 PM   #5
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Quote:
Originally Posted by moray james View Post
Doug: I just don't have the time to build you new panels but I might be able to get one of my buddies to build them for you. As to cost that would be between the two of you. That said I would be happy to let you use the jigs that I have but we will have to do some foot work to work it all out. As to cost that will depend on you mostly. If you want to use styrene louvre that is about 10 bucks for a 4X2 foot sheet so $40.00 in louvre. If you want to use acrylic louvre then it is about $20.00 per sheet. Then you will need spacer material @ about $20.00 and wire. I would suggest double build magnet wire with a gage of 30. A spool of that will run around $35.00 or so. Then you will need solvent adhesive at around$40-50.00. Diaphragm material is cheap but Licron will cost you about $75.00 for a large spray can. These are all Canadian dollars . That is probably the lions share right there so you can do the math. If you want to use acrylic transfer to assemble then you will have to check with local suppliers for the cost of that as it is spendy in small quantities. i would recommend LePages press tight green contact adhesive which goes for about $20.00 per litre. Probably figure in $50-75 for incidental and screwed up bits and pieces and that ought to cover all of your materials.
The first one will take the longest time after that they will go faster. You are probably looking at a couple of weekends perhaps less.
If you are not in a hell fire hurry I have a buddy who is in the process of building four new panels and if the switch over could be worked out between the two of you he would probably be happy to sell you his Acoustat panels once the new ones are built. You would be able to listen to the current panels and evaluat thier condition. They sound just fine. Send me a PM and we can discuss this all further. Best regards Moray James.
Moray,
Do you still have Acoustat's? This thread is a few years old so I'm not sure how dead it is. I have had 2+2s for 25 years and they have been in and out of storage several times. They are set up again now and I am so happy with them. Do you know if anyone has resurected the technology? I can still find parts her and there any very occationally a pair for sale if I'm willing to drive cross country to pick them up.

With your experience, it sounds like it would be very easy to set up a small production of these great speakers. I replaced my speakers grills (socks) with lycra about 15 years ago and will probably replace them again when we move to match my wife's new decour.
-steve
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Old 27th August 2010, 12:13 AM   #6
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Yes I still have some ESL's driven by Acoustat interfaces though they are also modified. Acoustat is now in the hands of a Chinese firm but I cannot give you any information about them and it would appear they have made changes.
Perhaps if you contact me directly we can discuss construction of panels. Regards Moray James.
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