Listening Room Dimensions... I'm building one and need your help


Sounds simple but I'm having a hard time coming up with most 'ideal' dimensions for this dual -purpose room that I'm building this year (hopefully).  



Purpose #1:
listening room for 2-ch hi-fi 
I have BIG speakers- several pairs 
*ideal is approx 25'x40'x12'
*want to sit 6-10 people in prime listening area 

Purpose #2: (other side of the room)
band rehearsal area (loud guitars, drums, keys, PA system, lots of 
*ideal is...bigger the better 

- I've read really good threads about general guidelines especially from Doctor Fine- hope he jumps in...
- I know the Cardas, and other rule ratios. But this room is a combination room so I'm not sure how much that changes anything 
- I know I'll probably have to use quite a bit of sound treatment 


My first inclination before research was 30' x 50' x 11'. 

What dimensions would you recommend and why??



128x128ramoneo14
@bdp24 


He uses it in the construction of his cables
I did not know that. I don't have any Cardas cables. Maybe I should try one?
My recommendation - don't do it. I simply would not try to make a premium two channel room that also would be for band rehearsal. I would find another place to rehearse. You may not have that option, but if you do, I advise you don't mash sonic attributes of the two together. 

If you go for the band rehearsal sized space, you will be building a cavern, not a room. The entire experience, including what gear you will need to run to make such a space seem appropriate will differ. Are you ready to pony up perhaps triple the money you have invested in audio to get the results appropriate for the space? 

It seems like you have lots of room to work with; why not build two rooms appropriate for their purpose? You can use a common wall, but use different construction techniques for each on other walls. You can send me the consulting fee if you do so. ;) 


For calculation of dimension based on Height online calculator.
Based upon creating as many resonances as possible.

http://www.mh-audio.nl/Acoustics/RoomDim.html