Audiocontrol Epicenter

[shredder1 10+ year member]

1/4 octave boost under center frequency with adjustable levels. You're enclosure better be tuned well for what content is about to be asked of it. Epicenters rock in a well tuned 4th in my experience if setup correctly.
Otherwise... especially in ported prefabs epicenters kill subs. User error to the extreme.

 

[spokey9 5,000+ posts]

Honestly I would just avoid them...more things in the signal chain seems counter productive to me

 

[Jimi77 Premium Member]

Almost every sub bass amp has a ~35hz bass boost knob anyway.