Bizarre ESL

[lpd]

I acquired these bizarre speakers in a trade from a friend as a beginning to the ESL speaker. The price was right so I took a plunge. These are a highly modified/bizarre version of a Quad 57. The three panels were turned 90 degrees to a horizontal position with the tweeter panel in the middle. They are raised 14 inches to put the tweeter at head level. There are no dust covers, but the owner indicated that with the cloth covers and bi-weekly vacuuming he used them for almost two years with no problems. The power supply/autoformer is from an ESL57.

From a few Quad enthusiasts I was told that the design of the speaker is problematic and that I should pull the panels and rotate them back to a vertical position for proper dispersion/axis. Also I was told that using them without dust covers, cloth covers used I will eventually damage the panels.

Because I'm new to ESL's I'm unsure of this advice and thought that I would ask here first. Any thoughts on these?

I connected them to my push/pull 6V6 amp and with a liitle patience on setup (a few hours, 7 feet from the back wall) I was suprised at how transparent they are. Bass is actually much better than expected although a little dry. The top end is great, with lots of sparkle. The soundstage is a little narrow, but not too bad.

[Andersonix]

They'll image better flipped to the intended direction, as the narrow panel is the high frequency section. But you knew that. Hopefully, it won't be too much work to reorient the frame.
Regarding covers, only you know who one day might want to stick something in them and hurt themselves, or worse, hurt the speaker.
You've got yourself a nice little esl project with the world's most famous esl ever, so there'll be no shortage of help. I'm jealous.

[MJ Dijkstra]

hI,

The quad turned 90 degrees is something I've heard before.
The treble panel is slightly curved. Right?
By turning it 90 degrees it will work a bit like a Martin Logan (although the curvature is probably less)
The vertical dispersion however will be poor.
Matter of taste I suppose.

[moray james]

MJ is right. It would be worth your while to play with the toe in angle. See if you can find a spot on the panel which will work from an image point of view. I would suggest starting with the spot directly between the inside frame and the first set of rivits in the tweeter panel. Have that point aiming directly at your head (both speakers). Then you can progress your way across the panel and listen at each step. You probably want to make sure your ears are on axis to the tweeter section. This way you will find out if things can be made to work and if you don't like it at least you have been there and done that.
I always wanted to reconfigure the 57 panels so that the two bass panels were stacked one on top of the other with the curvature as in your current frame. Then have the mid/tweeter panel mounted in a verticle orientation in the centre on top of the two bass panels. Just a thought. Good luck have fun, remember that stats like the Acoustat live very long lives and never know what a dust cover is. Regards Moray James. PS: simple adjustments to the tweeters vertical position can be made by tilting the frame up or down. I would expect tht keeping the panel vertival would be your best option but the tilt will give you some fast reference.

[lpd]

Thanks for the input and ideals. I was thinking of building new frames to orientate the panels with the bass drivers together and the tweeter panel vertical. As it is they sound very nice although the image seems a little smeared vertically at times because of reflections.

[I_Forgot]

Actually, in that orientation (90 degrees from original design), the horizontal dispersion will be poor and the vertical will be broader. The dispersion is inversely proportional to the panel dimension.

The curve is very slight and won't do much at all for the dispersion.

I_F

[Capaciti]

Hi,

by turning it 90°, the membrans original width is now the height. Since the new height is shorter the cells will reflect more sound to the floor and ceiling which is not desirable, due to additional room reflection.

In addition the sound stage shrinks but should sound more precise.


capaciti

[lpd]

The other consideration with this setup is that the panels have no felt or backing in behind them. I have them set about 5 feet from the back wall, but I'm going to try some blankets in behind them as an experiment to see how it affects the imaging. The soundstage is much small, but the image is very centered and with a challanged room I actually have a piano that is centered in the room with some depth to the keyboard where on conventional speakers, pianos always appear to be on both sides of the stage no matter how I set them up.

When I originally acquired them I turned them 90 degrees and set the frames onto chairs approx the same height as the stands to test the vertical arrangement, and the soundstage was much wider. The downside was the bass seemed mushy and boomy. In the position they are now, the bass is strong and tight, just a little dry.

I appreciate all of the help/info you guys have provided. I just wanted to get a second opinion before spending some $$$ to build new frames to put them in a vertical position. I have the original frames, but they seem really cheaply made to me and some of the bracing is delaminating.

[I_Forgot]

You can make your own frame like I did for my ESL-63s. It doesn't take much talent, and it doesn't cost much, but it is very sturdy.

Peter Walker is probably turning in his grave...

I_F

[Audiofool]

Since new frame is in order, Moray's idea of putting the treble panel vertically over two horizontally stacked bass panels reminded me an arrangement that was reviewed on HFNRR, almost 10 years ago. I would consider such an arrangement, but with two bass panels on the bottom.

B.T.W: from your picture it seems that your speakers are without the metal grills, but have the mylar dust covers. (but maybe my eyes are misleading me?)

Good luck with your project.

J.B