Dear Lance: First, I really like your Harbeths ( btw, any Harbeth ): great speakers.
There are many sub choices out there: The REL subs are very good ones but my advise is that you try the Velodyne HGS 12 or 15 ( second hand at very good prices ) or the new DD series. In my experience no one have the sub experience than Velodyne people and their today electronics ( internal crossover and amplifier ) are first rate.
I own Velodyne, two HGS-15, and before I buy it I test: Aerial, Revel, REL, Paradigm and Krell. The Velodyne's meets better and closer to my music/sound reproduction priorities.
Regards and enjoy the music.
Raul.
There are many sub choices out there: The REL subs are very good ones but my advise is that you try the Velodyne HGS 12 or 15 ( second hand at very good prices ) or the new DD series. In my experience no one have the sub experience than Velodyne people and their today electronics ( internal crossover and amplifier ) are first rate.
I own Velodyne, two HGS-15, and before I buy it I test: Aerial, Revel, REL, Paradigm and Krell. The Velodyne's meets better and closer to my music/sound reproduction priorities.
Regards and enjoy the music.
Raul.