See posts before!
I’m using a Dr.Q with bass as well, and i was disappointed when i heard how it sounds for the first time. Then i went trough these posts, and finally found the solution. THE TRIM INSIDE!
You can spend a few hours playing with it, but it’s worth it!
I think the noise you (and i) can hear at high filter response level is because this trim is not in the good position. Try turn it clockwise, to decrease the filter and increase the volume.

Regards,
Csaba