Merlin VSM-M and Bass

A bit of background:

Marantz SA-14 SACD player
Sonic Frontier Line 2SE preamp
Belles 150A Hotrod amp
Merlin VSM-M with BBAM

Setup and room:
diagonal placement
speakers about 5-6' apart and fairly close to the side walls in a 20'x20'x10' sloped ceiling room with a big opening into a 20'x12'x8' kitchen

I bought the Merlin's (VSM-SE) about 2 months ago and had Bobby upgrade them to the Millenium w/ BBAM. My question is how can I get more bass from them? These speakers are (were?) going to replace my Revel F30. The Revel's have the bass that I'm looking for, however, from maybe 100Hz on up, the Merlin's are much better. I just do not get the bottom end that the Revel's put out.

Integrate a sub? And if so, any suggestions?

Thank you,
p, the bam causes no mid bass hump because its boost plateau is actually centered at 35 hz. the vsm response is actually + or - 2.25 db. the tsm is + or - 2.75 and because the qts of the morel woofer, its response is actually boosted by over 1 db in the range up to 180 hz. it is also playing below resonance of 52 so the im distortion is higher and impedance variations considerable because the driver in not kept in linear drive like the scan/bam. i am sure what you are hearing is a room mode. if the vsm's were set up by the 1/4's rule that would probably disappear.
My VSMs (originally SE, subsequently updated) have seen almost 15 years of use in 6 or 7 different rooms. As some have noted, it may take a bit of work to get satisfying bass balance in any give room. OTOH, the one thing that I've never had to deal with in all these years with my VSMs is a mid-bass bump.

Ok, thanks for your inputs. I was worried about some relation between midbass hump and bam.

I will advice mi friend to take some room meditions...

I insist, Merlins are one of the best out there... Thanks Bobby
p, you must also make sure the speakers are level because if they are tilted back they can be made to sound overly full in the mid bass.