@ramtubes
Roger, you might want to read this:
http://www.atma-sphere.com/Resources/Paradigms_in_Amplifier_Design.php
If the Quads were close to the wall behind them, they will often have one-note bass. This often happens when a solid state amp is employed; the customer will note that there is no bass on account of the higher impedance of the speaker into which the amp can't make power, and so will move the speaker around, eventually finding out that if they move it closer to the wall behind it, they can finally get some bass. But this is not how *any* planar is supposed to be set up.
ESLs don't respond so well to voltage rules, depending on the speaker- the Quad ESL57 and 63 being pretty good examples- also the Sound Lab ESLs, AudioStatic and even Martin Logan (if you use a set of ZEROs to allow for their low impedance). The reason is, unlike box speakers, the impedance curve is not also a map of its efficiency, which is pretty much the same across its bandwidth (on account of its impedance being based on a capacitor rather than a driver in a box with resonance). This is typically a 9 or 10:1 change in impedance! If the amplifier output power varies with this curve, the result will be too much highs and not enough bass.
The solution we've found with our customers using Quads is to have them pull the speakers further out into the room, so there is at least 5 feet behind the speaker to the wall. In this way the bass normalizes and customers report that the Quad is playing bass quite well.
We are quite a ways off-topic; if you would like to discuss this further it would be a good topic for another thread.
Roger, you might want to read this:
http://www.atma-sphere.com/Resources/Paradigms_in_Amplifier_Design.php
If the Quads were close to the wall behind them, they will often have one-note bass. This often happens when a solid state amp is employed; the customer will note that there is no bass on account of the higher impedance of the speaker into which the amp can't make power, and so will move the speaker around, eventually finding out that if they move it closer to the wall behind it, they can finally get some bass. But this is not how *any* planar is supposed to be set up.
ESLs don't respond so well to voltage rules, depending on the speaker- the Quad ESL57 and 63 being pretty good examples- also the Sound Lab ESLs, AudioStatic and even Martin Logan (if you use a set of ZEROs to allow for their low impedance). The reason is, unlike box speakers, the impedance curve is not also a map of its efficiency, which is pretty much the same across its bandwidth (on account of its impedance being based on a capacitor rather than a driver in a box with resonance). This is typically a 9 or 10:1 change in impedance! If the amplifier output power varies with this curve, the result will be too much highs and not enough bass.
The solution we've found with our customers using Quads is to have them pull the speakers further out into the room, so there is at least 5 feet behind the speaker to the wall. In this way the bass normalizes and customers report that the Quad is playing bass quite well.
I know of no speaker maker who designs for high output impedance amplifiers.I can name a few- Coincident, Classic Audio Loudspeakers, DeVore Fidelity, Audiokinesis, Lowther, PHY, PureToneAudio and many more. Essentially, any speaker that works with an SET is working with an amplifier of high output impedance.
We are quite a ways off-topic; if you would like to discuss this further it would be a good topic for another thread.