Acoustat Answer Man is here

[Steve M]

Hi All,

I'm not an Acoustat owner (but my brother has a Model 1 or 11, so do I qualify as part of the discussion ??).

Just wanted to add that for repairs or DIY builds you can get mylar of various thicknesses and conductive coating very cheaply from here: Electrostatic Loudspeakers By ER Audio . I have the ER Audio ESL-3, a thin membrane (3.4 micron) superfast stat, fabulous sounding speaker btw.

Regards,

Steve M.

[hella356]

Originally Posted by bear

Andy, no problem... you certainly have information that I just don't know anything about at all...

hella, I did not end up with an angle!

The whole idea was to have the "wings" be adjustable. Which they are. In practice I think I ended up using them at an angle that was similar to the factory frames. Although I did at times angle the inside cells a bit more than usual to get better imaging (you "see" mostly the center cell) without losing the bass and mids... but that was somewhat specific to my particular room set up (more than 2x longer than the width at 14' - but the listening position varied between ~ 10ft back to double that or more...).

There's not much to look at with them as I never really got the thing to a finished state, although it is/was functional. When you look at it is is 3 cells more or less floating in air, held from behind at some distance by a frame... with the spectra cells in place there are a lot of wires dripping out the bottom! I did put one set into nice silvery woven sleeves... better.

_-_-bear

That is a most interesting sounding setup, bear. Do you have any photos? My somewhat slapped-together 3+1 setup is sort of hideous looking to most (especially the girlfriend) but they do sound rather good. If I could live with only 3 panels per side I'd definitely try your design. Unfortunately, I've heard what 4, 6, & 8 (and the more, the better) panels per side sounds like in my room, and I know I can't settle for less than 6 per side in the long run; the bass is just too good, particularly with rock, which I listen to a lot, and on large orchestral music. The greater weight and impact are worth it to me. The increased number of panels just seemed to energize the room in an invigorating and immersive fashion.

[bear]

Hella, as I said what I did was not really a finished design... more a cobb'd together prototype... I don't have any pix of it on hand, but I might share them with you privately... it's not suitable for public distribution. Heh.

The 3s bass is not as strong as the 4s, that is for sure. But I use my own design subwoofers, so that was not a big issue for me. You can see them with CLS on top if you go to my website and look at the speakers page and then to the Quadripole subs... no lack of weight with them, they'll hit you in the gut if they need to. But in my room the 3s had better imaging and still good midbass.

I had tried a floor to ceiling 1+1 stack (low ceiling) and did not like the upper bass nor did I like the imaging due to the gap at the top of the cell going to the next cell... fwiw. I figured if I
was going to have put wings on it I would then rather go with a 2+2 or 3+3 (aka 6) anyhow, and the point of the 1+1 experiment was imaging...

_-_-bear

[hella356]

Thanks, bear. If you'd like to PM me some pics, I promise I won't judge the visual aesthetics of your design. I'm just curious about the functionality of your setup. Here is what my current 3+1 "beauty" looks like:

Acoustat panel angles? 8" vs 9" panels?

[Steve M]

Just out of interest, what do you guys reckon a pair of Acoustat Spectra 66 in good condition are worth these days? I know they have become unobtainium and are highly respected.

Regards,

Steve M.

[AcoustatAnswerMan]

Originally Posted by Steve M

Just out of interest, what do you guys reckon a pair of Acoustat Spectra 66 in good condition are worth these days? I know they have become unobtainium and are highly respected.

Regards,

Steve M.

There weren't many of the 66 or 6600's produced, and most people who have them don't want to part with them (and I can hardly blame them!). But if you were to find a pair in good condition, and they were actually for sale, I wouldn't expect the price to be any less than $2000/pr, possibly much more. Being such a large speaker, it's often a matter of finding the right seller & buyer in the right place, since shipping is usually out of the question.

I was lucky in finding my Spectra 4400's, which I bought several years after I left Rockford. I bought them from another ex-Rockford employee, who unfortunately had them stored unprotected, so there was some cosmetic re-hab work to do before they were ready for the living room. That meant that I was able to get them for a very nice price (don't ask), but with my familiarity with the product, I was able to get them looking almost new. And NO, they are NOT for sale!

[Steve M]

Thanks Andy, can you tell me does the Spectra 66/6600 sound different from the other Acoustat models, especially in the treble response? I thought I read somewhere they might use a smaller (less wide) treble strip for a stronger more extended treble response?

This is exactly what the ER Audio ESL-3 that I posted above has, it is a two way design with a dedicated 2" wide central treble strip that is capable of doing 25 kHz. When you hear it, it makes other stats like Martin Logan and my brother's Acoustat Model 1 sound a little lacking in treble attack.

Regards,

Steve.

[moray james]

Steve: I cannot remember the diaphragm thickness of the ESL lll but it is either 6 or 3 microns probably 6 microns thick polyester. The Acoustat has a 65 gage HS Mylar diaphragm. That's .65 mil thick so the ER is a far lighter thinner diaphragm film. That is likely the difference which accounts for what you are hearing as far as treble response goes. The Quad ESL 63 uses a 3 micron diaphragm. Remember most dynamic speakers use a one inch dome for their high frequency reproduction so it is easy to see that even a narrow vertical line source ESL has no trouble making more than enough treble output. Regards Moray James.

[Steve M]

Hi Moray: you are spot on about the membrane thicknesses and the resultant treble response, my ESL-3 is 3.4 microns thick so is light and is superfast. However, there's also the aspect that a highly charged 2" wide mylar ESL strip produces much higher frequencies and intensity than a 6" wide one, or one that is generally wide and operating full range like an ML or Acoustat.

Here's a pic of the guts of my ESL (ESL-3 at Left) ...it is designed as a 'true two way' with a treble strip in the middle and two full range ESL drivers on the sides. There are inherent advantages with this approach, better upper frequency response for one (up to 25kHz), and extreme d'appolito type focus to the soundfield. I'm surprised more ESL speaker designers don't do it this way as it takes the ESL concept to another level, IMHO.



Regards,

Steve.

[SY]

Steve, what do you do to prevent lobing in the horizontal plane?