Yes, I have heard th M3's as well, and was impressed. My buddy is a dealer, and we went overboard trying to find fault with them - using very expensive high quality amps and cd player, and comparing to speakers in their market space and just above - and I was impressed.
There are numerous concepts to designing a listening room. The primary driving force must be the local building codes and safety codes. Structurally, mechanically, and electrically your renovations must follow local codes. This is for safety reasons.
Beyond that, a friend in the acoustic industry helped me build a proper listening room in my previous house. It is very easy to spend BIG dollars attempting to address all of the factors. Things like spacing of studs needs to be more random (not 16" on center for every stud), with a mixture of wall thicknesses (2x4, and 2x6, and 2x2) portions of walls to eliminate resonances. Hanging wall covering on furring strips attached to the studs to eliminate continuing resonances from one material to another, varying thickness of wall insulation, using differing R values and fibeglass and mineral wool based insulation....and on it goes.
Electrically, use a couple of circuits if possible. Here is a tip - use a different circuit to feed the lights than you use to feed the system - a tip I learned from building my garage (put the outlets and lights on different circuits, so if you blow a circuit at night with your drill, you can still see!). Use a couple of outlets per circuit, and remember that equipment plugs add up in a hurry! Count your current pieces (TV, DVD, Amp, Powered Sub, VCR, etc...) Power bars can be used, but since you have a clean slate, put extra outlets in and plan ahead. Ensure proper polarity and grounding of the outlets, and panel connections.
As for burying cables in the walls, you need to weigh the pros and cons. The planning before installation can eliminate, or reduce the risk of some of the cons.
Pros:
- unsightly cables are out of sight and harms way
Cons:
- eliminate flexibility of moving equipment to new positions in decor
- difficult to repair damaged/problematic cables in sealed walls/ceilings
- costly, as patch cables are required at amp and speaker ends to connect to faceplates.
- introduction of more points of failure
- less opportunity to experiment and upgrade cables (although this could be a pro as well LOL)
- careful routing around sources of interference (computer data network cables, flourescent lights, cable/satellite feeds, electrical circuits, telephone cables - 90volt ringing, etc)
- adherence to local electrical and fire codes for inwall wire - FT6 wire rating is recommended
Note that some of the cons can be eliminated by planning. For example you can use PVC conduit to feed the cables through walls, and this allows replacement, protection and covers some building code articles. Note that there are cables that can be purchased that are coloured to match decors. They offer flat cables that can be used to solve numerous issues.
Having built such a room, the main premise is for the room to become neutral, or not add, emphasize, or colour the sound. Having played in college in an anechoic chamber, I can see the reasoning speaker designers test designs in neutral enviroments. But this is difficult to reproduce in a home. Odd size rooms can help, the same way Ian designs cabinets that are not square. This eliminates certain variables that can affect sound.
My recommendation would be to ensure proper power, build with some thoughts of acoustics, tune with fabrics and furniture after, and spend the extra money on the pieces you will choose to include in the system. There are numerous resources on the web, so search them out. This was my thought when I designed the room in my new house. It contains equipment of great quality, and the room is somewhat tuned.
Let us know how you make out!
Regards,
BBIBH
