Strange room response

[thommy]

Here I am again. This time it's about my friend who noticed an unusual phenomenon. He owns an integrated amplifier Accuphase E-5000, digital voicing equalizer DG-68 and Dynaudio Confidence 20A speakers. Using DG-68, he adjusted the frequency response of the room. The sound is excellent, the bass is controlled at the listening position. However, when he turns off the equalizer and uses the DG-68 only as a converter, the bass is many times weaker and the sound is much worse. He thinks that it would be logical that after turning off the equalizer, it would be exactly the opposite, i.e. that the bass would be more pronounced and boomy. It has a rather large room (4 by 8 meters). How often is the case in practice that the equalizer has to boost low frequencies? What do you think could be the reason for this phenomenon? Thanks in advance.

 

[staticV3]

How often is the case in practice that the equalizer has to boost low frequencies?

The Equalizer doesn't have to do anything. It does what it is configured to do.

What do you think could be the reason for this phenomenon?

You friend's equalizer is configured to enhance the bass response of their speakers. Turn the EQ off and bass drops.

The Equalizer could just as well be configured to reduce the bass of your friend's speakers.
In this case, the opposite would happen: turning the EQ off would add bass.