Supplementing KEF Ref 3 METAs

@madfloyd just seeing your question.  That was one of the options/recommendations from the PS Audio folks.  I tried direct to my tube preamp and also off my Hegel amp.  The F12's sounded tighter and better aligned off the KEF terminals using the high level input.  The REW Spectrogram was smoother as well.  I did have to flip the polarity of each sub.  They disappeared (in a good way) after.

I have a pair of R3 Metas that I supplement with a pair of HSU subs, The room is about 18x12 with a large opening at the rear. Could never get satisfactory low end with just 1 sub but adding the second has made me a happy camper.

The subs are in the front corners, basically next to the speakers. That gives me good bass at my listening position. Interestingly, if I stand in the rear corners, the bass is overwhelming but seems just right in my recliner.

@greatdivide71 I appreciate the response!