What is the best audiophile speaker for a tiny square room?

Sound Labs are the state of the art in electrostatics, and the Majestic is IMO one of the top five speakers made if price is no object.

But AS MA-2, which is usually recommended with SL, produces 1600W of heat just on idle (2 Monoblocks together). Plus, it is >$20,000.

Given the size of your room, if you are thinking of Atma-Sphere, my first recommendation would be a set of MA-1s rather than MA-2s. You don't need the power, and with changes that Sound Lab made in the last 5 years or so, the MA-1 can now do on the Sound Labs what took a set of MA-2s prior.


If you are planning solid state amps for Sound Labs, my first recommendation is Pass Labs.


But if heat really is the issue, then a very practical thing to do is to set up a simple and inexpensive set of ducts in or near the ceiling. They can be powered by a low RPM squirrel cage fan that can be dead silent. I've seen installations like this- one using our MA-3 amplifier, which has 42(!) power tubes in class A **per channel**- and yet the room stayed comfortable all day and all night with the amplifiers on. You might consider this, especially if you like the sound you are getting right now, since it only costs a few hundred dollars to implement.

How does class A fit into the sound quality equation for AS amps? Some people say for tubes, class A doesn't make that much difference- the way it does in SS amps. What do you think?

Class A in a push-pull amp is nice because it helps reduce distortion at all power levels. This is about the operating point of the output device- the class A point being where distortion of the that device is at a minimum from zero to full power. It is audible in a tube amp- make no mistake!

You're going to be hard pressed to beat the Soundlabs. Are you sure you shouldn't be looking for cool-running non-class D amps instead?

I’ll have to object to your blanket assertion. Class D goes swell with MY ESL’s. Better than the last three AB’s.

The problem is that a class D amp behaves as a voltage source and this does not work well on most ESLs. The reason is that a full range ESL like the Sound Lab has a variable impedance curve that varies by nearly 10:1 from the bass peak to 20KHz. But this is not due to a driver in a box as everyone here knows- its due to being a capacitive load. What this means is unlike a driver in a box where the impedance curve is a map of how efficient the speaker is at various frequencies, the impedance curve of an ESL really has nothing to do with its efficiency. Put another way, to make 90dB of sound pressure at 60Hz you need the same amount of power as you do at 5KHz, despite the impedances being quite different at those frequencies.

This is fundamentally unlike box speakers. So if an amplifier can double power from 16 ohms to 8, from 8 ohms to 4 and from 4 ohms to 2 (and most solid state amps including class D can do this if they are not at full power) you can see that its going to be making too much power at high frequencies, so it will sound bright. Now the Sound Lab has controls (unlike most ESLs) that allow for a bit of compensation- you can turn down the Brilliance control, and set the bass jumpers for +3 or +6dB and that helps compensate for this problem. What is needed is an amplifier that can make constant power regardless of load impedance rather than constant voltage. Martin Logan and a few others get around this problem by setting the bass impedance quite low- 4 ohms is typical and thus the 20KHz impedance might by only 1/2 ohm. This causes the speaker cables to be a significant series resistance and the amp itself to have troubles making power at these frequencies (but IMO/IME they still tend to sound a bit bright).


But Sound Labs have a 30 ohm impedance in the bass, and simply put, most solid state amps don't make much power into such an impedance. For example a solid state amp that can make 600 watts into 8 ohms makes slightly more than 150 watts into 30 ohms, and this is where the majority of the energy of the musical signal is concentrated. For this reason, a tube amp of only 150 watts can easily keep up with a solid state amp of 600 watts on this speaker!