How to design music room?

I am building a garage and adding an "office" over the top end. This is going to be me retreat. The garage space is roughly 32 X 27 and I am adding a second story on one half; appx. 16 X 20? My speakers will be BW N803's. Any ideas on how to, size, etc.?
I am sure Rives will plug his services here. This is meant as a suggestion, if I were to build a room, I would seek professional help.

At the least, I would search the old threads for recommended books, and do some major homework. It is mind blowing how much the room can make a difference, and if starting from square one do things right.

Make sure the floor is well-insulated. Room-over-garage can lead to very cold floors if not done correctly. Tubes won't even help!
Check Robert Harley's book on High-end stereo. He explaines how to figure whether you will have a lot of interactions with the size.

What are you looking for? Noise isolation for listening? A good acoustical environment? Both? Both of the questions could be easily addressed, but you'll need to be more specific. Cheers!

Sit down with the architect and explain all your issues. You will want to use construction materials, which prohibit the transfer sound into the walls, ceiling and subfloor. From my own experience I would have the roof rafters/trusses designed to receive two layers of 5/8 sheet rock. The floor joist/trusses should also be designed to add Dura Rock to the plywood subfloor material. Dura Rock is a cement-based material, which is used to provide a firm level base for ceramic tile, when installed over wood floors and walls. The material comes in 4’X6’ sheets and is joined with fiber tape and adhesives. My ideas are only to give you something to think about. Please use a licensed Architect/Contractor and always get a Building Permit.

Your Friendly Building Inspector
Unless you are prepared to do a lot of research I would suggest someone like Rives or Rives to give you advice. Stay away from the high end acoustic companies. They are a rip off. Do a search on the threads here and you will find a wealth of good advice. On the floor you should do a double subfloor with 1/2 inch or better cork in between the two layers of subfloor. You should also consider rubber strips or other separation methods between the joists and the first layer of subfloor.
Make sure that you play the music in your room on the first place:-)
primary goal is the best accoustics, secondary is noise isolation, and overall goal is listening nirvana
Steel door so your wife cant get at you......
If I had a chance to do whatever I want, I would build something like :

Well, at least try to build room with "golden ratio” dimentions.
Thanks for the site info Nar com, and the others. I am looking for an architect to draw up the plans, I have the basic design in mind. I want a south facing window which in itself will affect resonance, but I don't suppose there's any getting around that, except maybe to add wall coverings and a thick carpet
I have a bow window, which is a big no no. I also have a fabulous view of a pond and great light. I have put systems in the basement for purity, but have opted for ambience. I really enjoy the music much more with a great view and nice light. On the other hand I have taken great pains to install heavy duty drapes for when I want do more serious listening and I have added considerable acoustics to make the room still sound great with drapes open.
Thanks to all for advice offered. I did buy Harley's book and now have my room dimension figured to minimize resonant modes. However, that book gives no info re; building materials. Alton Everst has several books that deal with those issues but seem awfully "techno" for my needs. Does anyone know if any of his books offer specific info on the exact materials to use in the room construction? One of his books; "studio....on a budget" discusses the issues but I don't know if he gets right down to the materials issue.