How to fix a lack of bass Null

K_rose - maybe I'm missing something, but if you have reflections between two walls you should have amplification on even reflections 2, 4, 6 etc (in case of 5.25m it's 33Hz 66Hz 99Hz etc) and nulling (valleys) on odd reflections 1,3,5 etc. (frequencies in-between).

You should have the same amount of bass - only points of peaks and valleys will be different. It is possible that peak at 33Hz is useless (lowest bass E=44Hz, lowest piano A=27Hz but seldom used) and 49 Hz is suppressed giving you impression of weak bass (lack of extension). Damping room at low freqeuncies is not trivial and deep pattern foams are expensive and ugly.

You will get the strongest bass with speakers and listening spot at opposite walls.

The only speakers that don't do peaks and valleys are bipolar speakers (planar, electrostats) but they have modest bass to start with.

Try to toe in speakers at almost 45 deg angle - it will even up bass a little, will probably narrow the image but it will widen sweet spot. Room mode calculators are often very complex (3d plots) and might not be very helpful. Best bet to see what is happening would be to get good sound level meter and test CD.

K_rose -

343/5.25/2=32.66Hz where 343m/s is the speed of sound, 5.25m is the distance between your walls, 2 is because you need two times distance to amplify (from speaker to back wall + back to front wall + front wall to speaker = 2x distance between walls). Exact multiples of 32.66Hz will be multiplied as well since their wavelength is an even fraction.

Nulling is pretty much the same with odd divisions.

Magfan - it's getting too complicated for me. I saw 3d graphs of the room and it shows kind of "domes" instead of waves (combined effect of all walls). People with better math skills can understand it probably further.

Magfan - 3/4 is good enough for me. I have echo problems in my room but I'm not going to hire consultant - way too expensive for me. I will study the problem myself and settle for 3/4 (or even 50% improvement).

Shadorne - I will gladly switch my room acoustics for tall blonde Swedish girl. Do you have her phone number?