Ideal design for a new music room


I'm designing a new house which will include a room dedicated to enjoying stereo music reproduction. In my experience, room acoustics have a huge effect on the sound in any particular room.

I'm interested in ideal dimensions, structural materials and finishes. Any experiences and stories anyone?

The music I mostly enjoy is classical, including organ, choral, chamber, solo instruments and orchestral. 
128x128encore
That's a mighty big subject, one for which professionals make a good living addressing. Try Art Noxon at Acoustic Science Corp. For a start, Google "Golden Ratio", and take a look at the Cardas website.
20 x 30 with high vaults of 20 ft  will be good.

Of course you need acoustic treatment after ward.

Some people prefer carpet over wooden floor.

But it depends on the personal taste.
As I understand it, the golden ratio applies only to rectangular rooms. It’s also quite problematic to apply. I’m hoping to avoid the problems the ratios try to solve by starting out with an asymmetrical room. 

Here are some considerations, entirely without input (so far) from acoustic professionals:
  • the walls, floor and ceiling should be rigid so they will not vibrate and contribute to the sound. This is important for the low notes.
  • The floor perimeter dimensions should not be a perfect rectangle with parallel opposite walls in order to prevent standing waves - cancellations of some frequencies and boosting of others. Would rounded space like a band shell be best?
  • Would a stable 3D sound stage be more likely in a room that has a physical stage facing a room that widens into the listening area?
  • Then there are the livelyness and brightness issues which will require carpeting of some of the surfaces, the floor to start. How about the ceiling or the back wall?

Thanks for your input,

Peter
A room that is not a rectangle or with any parallel surfaces then introduces a whole host of issues in speaker positioning (as each speaker will see a very different set of reflection points). Interesting discussion of this topic in Roy Gregorys experience of his new room 

http://www.theaudiobeat.com/blog/wilson_audio_alexx_thors_hammer_2.htm