Someone please clarify how the RR2150 bass boost works when operating WITHOUT a subwoofer:

(1) Can the 55Hz/65Hz/80Hz front panel control bass boost be applied as 3 separate adjustments to emulate a 3 band equalizer, or are you just able to pick ONE frequency?

(2) With the above, can you select a range of dB values for the amount of dB boost or are the choices limited to exactly a 6 dB boost or else no boost at all?

(3) Separate from the 3-setting bass boost control, Is there a different independent control for the traditional "bass" knob at 50 Hz?

(4) If so, does this mean you can have two types of bass adjustments in effect at once?