Catfishbob,
the thing w/ every room is what kind of resonances is it going to have? And, how do these resonances interfere with the music/program material?
These resonances are known as room modes. You can have 3 types of room modes:
* axial - involves 2 parallel surfaces such as opposite walls, floor + ceiling. These modes are the strongest in amplitude hence interfere the most w/ the music,
* tangential - these modes involve 2 pairs of surfaces such as all 4 walls, 2 walls + ceiling + floor. the amplitude of these modes is 1/2 that of the axial modes,
* oblique - these modes involve 6 surfaces such as all 4 walls + ceiling + floor. These are 1/4 the amplitude of the axial room modes.
based on your approximate room dimensions of 16' X 12' X 7.25', you could have
* axial modes at 35Hz along the length of the room, 47Hz along the width of the room & 78Hz along the height of the room. The above stated freq & all their resp. harmonics. Since these are strong modes & in the deep bass, mid-bass regions they are likely to mess with your overall bass response. You are likely to hear bass overhang - bass from the prev notes stayed around too long & bass from the next note interacts with. Bass smearing/bass fuzziness.
* tangential modes at 59Hz along the length of the room, 86Hz along the width of the room & 91Hz along the height of the room. Again, these freq & all their resp. harmonics.
You also get oblique room modes but since their amplitudes are much attenuated, if you treat the axial room modes you pretty much are going to resolve 90% or more of your issues.
It would be a good idea to treat the room for deep bass & mid-bass (even tho' you are unlikely to get deep bass response in such a small room) so that you get a more even spectrum after-treatment response. Once you treat the room for bass you'lll have to listen to ensure that your music doesn't sound tipped up in freq (meaning to say you killed the bass too much & the music sounds thin). Treatments for the 300-500Hz region & also higher might be needed. All of this will be iterative once you treat the room & listen - it's a balance between too much & too little.
