When is a Listening Room Too Big

You are right about sometimes less being more, especially in the case of a very lively larger room.

I think large rooms work well with Maggie in particular. The best Maggie setup I ever heard (and among the best I have heard anywhere) was at Jim SMith's Audition shop in Birmingham AL. SHowroom was large, but not huge. The panels were positioned almost in the middle of the room with lots of space behind and slightly more in front. I was blown away and bought a pair right then and there and had them for years until I moved into my current home where my room is fairly large but L shaped and narrow and optimal placement was a problem.

A sub or two or four can always be added if needed, but I suspect the other charms possible in a large room has a good chance to float the boat alone.

I tend to think of most peoples rooms as the main bottleneck with MAgnepan speakers. Most are not large enough to really let them be set up optimally and shine.

Yes you will likely want a good bit of power and maybe even a fairly beefy tube amp to drive them to higher volumes in most larger rooms though, if that is something that matters.

Good point by John regarding how one may have a preference for a certain size room that has nothing to do with sound quality.

I have 3 rooms running speakers off my main rig using in-wall speaker wires that run from the room where my gear is located. That room is 12X12 with standard height ceiling.

Above it is the sunroom, similar size, but cathedral ceiling.

Then I have my "large room" which is ~ 20X30 but L shaped, so smaller in volume.

I listen a lot in both the main 12X12 room and the larger L shaped room. Each has their unique charms in terms of how the music is presented, like going to different size venues for a live performance. Which is best? Hard to say. Smaller room is cozy and intimate and sounds great. Good for getting intimately involved with the music. Larger room presents things on a larger scale and is good for being able to just sit back a bit and soak it all in and also sounds great. Hard to choose just one, but I could live with either if I had to.

Sunroom has its own appeal and belongs to my wife, so my options are limited there and the sound is quite good there as well, but I use it more for casual rather than critical listening.