Room Demensions, am I in trouble?

You are actually facing a couple of issues (Rives can expand on this). First, you will be in a pressure zone whenever frequencies fall below about 27 Hz (based on the longest dimension of your room at 14 ft). This means that you will get an artificially high sense of bass (sort of like being in a car, where the bass is very high -- by the way, ever notice how bad that same bass sounds outside the car?). Basically, it is as if you are inside the speaker. Second, your standing wave zone is pretty big -- from about 27 to 480 Hz with the most critical region in the 27 to 240 Hz region. This is where you will notice peaks and valleys in bass -- depending in part on where you sit. The troughs (where it will sound weak) are in the 50-70 Hz zone, the 90-120 Hz zone, the 120 - 140 Hz zone, the 140-190 Hz zone, the 210-235 Hz zone and the 240-280 Hz zone. You may notice a dip in the 240-280 Hz zone and the 280 to 320 Hz zone too. These are the areas where there are a 20-40 Hz gap in sound reinforcement. Peaks will occur more rarely -- at about 45 Hz, 140 Hz and 280 Hz. These are the areas where two or three dimensions of the room will reinforce the same frequency. With your room being reasonably close to a cube (the worst case acoustical environment), these things happen.

The good news is twofold. First, you can probably adjust your subwoofer to compensate for some of this. Second, the Thiels tend to sound pretty natural in most environments. You will get some dips and peaks in the bass regions, but I suspect you will still greatly enjoy the experience in your new home. As others have recommended in the past, pick up a copy of Alton Everest's book -- actually he has a few great ones. You can learn one heck of a lot about acoustics. Certain acoustic treatments can help too. For example, by absorbing the specific peak frequencies, the rest of the bass will sound more even.

Fellow audiogoners, I invite your comments and corrections. Am I oversimplifying? Am I just too simple? ;-) Rives, where are you buddy?

my calculations show room nodes too close together at 7&8 and 15&16. If your measurements are correct you will need to correct for the like node cancellations that will occur at the noted points and others will likely occur in your seating position. otherwise my only comment is, that is a sheet load of speakers for such a small room and should likely give you some pretty incredible theatre sound and overload + room resonance galore! Go three channel + subs trade one set of speakers in for some tiny ceiling mounts and save some precious space.

AudiogoN post set up will not allow for my chart to post properly so each line has a accendinghz and differential value except the last doesn't have a differential. Length has 7 values, width 6 and height 4

Length Width Height accending differential
14 12 8 order


40.35 47.08 70.62 40.35hz 6.72
80.71 94.16 140.54 47.08hz 23.54
121.07 141.25 210.82 70.62hz 10.08
161.42 188.33 281.09 80.71hz 13.45
201.78 235.41 94.16hz 26.90
242.14 282.5 121.07hz 19.47
282.5 140.54hz 0.70
141.25hz 20.17
161.42hz 26.90
188.33hz 13.45
201.78hz 9.035
210.82hz 24.59
235.41hz 6.72
242.14hz 38.95
281.09hz 1.40
282.5

Thanks for the incredible info!!!
If I understand you correctly, I'm looking at some pretty boomy bass? I'm not real clear on the technical measurments you guys put out there, but I'm hoping that by installing some bass traps I can tame some of the out of control bass. I'm also wodering if I would benefit from instlling some sound damping material behind the listening position and the first reflection area on the side walls?

Nice post, Ozfly. Mhubbard, DO find Rives. I would suspect that you'll have to exoeriment with moving that sub around a lot. The Thiels go down pretty low, and with room support maybe you could do without it?! Sidewall reflection control is always important; yet you might not want to tame them TOO much as otherwise you'll not have a wide enough sweep spot in such a small room for more than one-two people. HT isn't easy....

Thanks Ernie. Mhubbard, while my knowledge is much more limited than many others on the topic, I would suggest three things. First, tune your subwoofer carefully (probably by turning it down to compensate for the pressure zone). Secondly, see if you can tune the room treatments to absorb the peaks at 45, 140 and 280 Hz -- this might be a tough thing to do. Third, experiment with your listening position -- some spots in the room will be better than others. By the way, the Rives site is a good one. The Rives equipment might also help (seems like it would, but I have not personally tried it). Good luck.