Best speaker for the Spectral DMA 360 series 2 amp

Onhwy61
You say "very few direct radiating". Do you think larger panels would be better for the room?

Also just keep in mind I'm looking for the best bang for the buck for this room even tho I may not be able to afford the ideal.

I have no idea how Magneplanars would work in your room.

The Zu Defs are a little over $10k, while the JBL Synthesis and CARs are closer to $20k. The most cost effective solution would be to pick up a pair of vintage Altec VOTT type loudspeakers and refurb them. They are specifically designed to work in the large spaces. A decent condition used pair and the cost of refurbishment might run around $4k. There's a story in the current Stereophile about getting Altecs to work at their best.

Magnepan or dynamic speakers? There is a huge difference in presentation between these vastly different speaker types. This is one decision you should make before going forward.

For years Spectral teamed with Avalon Acoustics and MIT cable. I believe they called the system 2C3D or two channel three dimensional sound.

Of the speakers you mention, the Aerial is probably the most bass heavy. That may be the best match for your room. For your amp, though, you may want to consider some other options. Here's a few things that may work well with your amp and your room: Vandersteen 3's and a pair of their subs, Martin Logan Cls's and a pair of subs (I've heard them several times with Kinergetics Research subs and they sounded great but I don't know if they are still made), and a pair of Genesis (I forget the model but they were around $15000. They look like a pair of Watt/Puppies but they have powered subs. I heard them in a room like yours and they sounded very good.)