Dynaudio SUB 250 MC 用户手册

Subwoofer and main speakers are perfectly matched, when the combined frequency 
response is smooth without bumps and gaps. A neutral sound will be the result.

A gap in the frequency response occurs, if the cut-off frequency of the subwoofer is 
set too low and of the main speakers too high (or if the main speakers are not able to 
reproduce low frequencies accordingly). In this acoustic hole you will miss some 
signal information and experience a thin bass sound.

In the other case you will experience unnatural and bloated bass sound, if the 
overlapping area is too large. The combined frequency response shows a bump, as 
the sound pressure levels in this area are increased.