Speakers for Atma Sphere M60 mk3

@sbank

+1

OP: FYI, I have a LSA Voyager GaN 350 (solid state) that has exceptional sound and is very affordable. Ric Schultz modifies them to take them to another level.

I have Emerald Physics 3.4s which are Open Baffle with 12" concentric drivers and one inch polyester tweeters. Super easy load. If you’re patient you can get a great deal on this brand (there are a number of similar models- a couple which incorporate 15" woofers) all of which are no longer made. See my Virtual System for pic

Many people including myself use Atma-Sphere with Merlin speakers.  A match made in heaven, imo.

Should have also said the A/S M60's with Merlins although the S30's do very well at lower listening levels and/or smaller rooms.

I’ll reiterate some variations of similar speakers here, having owned a few Atma-Sphere amps myself. The Quad ESL 2805 electrostats would sound sublime in that size of a room since they won’t reflect too much off the side walls, and you should be able to easily give them 48-60 inches of breathing room from the front wall.

For Devore, I’d suggest you look at the O/93 as well. They are just simply lively, dynamic, and transparent.

The SF is a 4 Ohm load, rated 91 dB Sensitivity. To convert to Efficiency, which is a more useful spec for tube amplifiers, you have to subtract 3dB on account of the fact that Sensitivity is a voltage measurement, while Efficiency is power. 2.83 Volts into 4 Ohms is 2 Watts and the Efficiency spec is 1 Watt/1 meter. Thus we arrive at 89 dB.

I don't think the M-60 can make enough  power in a room of that size, even when using the ZERO autoformers to correct for the impedance (and also results in more power, about 80 W/channel).

IME, having used speakers of that efficiency in a room of similar size, I found 200 Watts to be more satisfying. You have several options; if you get the M-60s and keep the SF loudspeakers, you want a set of ZEROs and you'll be living with occasionally overloading the amps.

Or you could get a more efficient loudspeaker. Some good suggestions are on this thread (I don't think the older Quads would be good since they are not all that efficient).

Or you could get an amp with more power for the SFs. If you go this route, FWIW our class D amplifier sounds a lot like our M-60s and has no problem driving 4 Ohms with considerably more power.