A few months ago I added an SVS Micro 3000 sub to my system (PL EVO 400, Modwright/OPPO 205, anti-cables, reworked '78 KHorns) as a result of comments on this forum. My small house requires a living room installation and the right KHorn has only inches of wall before encountering a large door opening between living and dining rooms. The sub fits perfectly under the four-legged antique buffet I modified to install my electronics, and it's located on the same wall the other side of the doorway.
It made a sonically amazing improvement to my listening experience!
The extra 10Hz lower frequency range has smoothed and reinforced the soundstage in ways that I wasn't prepared to believe.....and make no mistake, I am now a confirmed believer!
The sub has even made up for the bass loss that was noticeable (to me) on the right side of the room.