Wall reflections or back reflections generate a set of cancellations at different frequencies (also called comb filtering). The first cancellation notch can be between 6 dB and 20 dB deep. Equalization of the monitor output level does not help, as the same level change applies also to the reflected sound.
The first solution is to flush mount the monitors into a hard wall (creating a very large baffle) eliminating the rear wall reflections and therefore cancellations. Another possibility is to place the monitor very close to the wall minimising the gap. This raises the lowest cancellation frequency so high that the monitor has become forward-directing, and the cancellation no longer occurs. Remember that the low frequency boost should be compensated for when the monitor is mounted close to the wall (up to +6 dB gain).
Alternatively, the monitor could be moved considerably further away from the wall to eliminate back reflections. The cancellation frequency will be lowered below the low frequency cut-off of the monitor. When the monitor is moved away from the walls, it also moves close to the listener. This increases the direct sound level and reduces the reflected sound level which improves the sound quality.
Acoustical treatment of the walls is another solution. It could mean modifying the wall and making it very absorptive so that the amplitude of the reflected energy is small and does not cancel the direct sound. When a subwoofer is used to reproduce low frequencies the monitors can be placed more freely. The subwoofer(s) should be placed close to the wall(s). The monitors could be placed at distances where low frequency notches do not occur in their pass-band.
Jeg har vurdert Q serien bare for å ha Kef i hus. Btw, iflg Steve Guttenberg så nevnte han at B600 var langt bedre enn LS 50. Rett nok i hans ører. Kanskje jeg bare skal gi det litt tid før jeg gjør noe impulsivt. Det blir jo dyrt etter hvert. 
