M&K's dual driver units are very nice as is the Muse Model 18 (discontinued). If you are looking for fast rather than deep base, the M&K dual 8" units (MX-70, MX-700, and MX-7000) are awesome for the money in small to medium rooms. Larger rooms could benefit from the Muse, or maybe a Bag End 18". The Mirage BPSS-210 is a good one as well (also discontinued).
What subwoofers are suited 4 audiophiles
I am looking for an accurate sounding subwoofer that will blend gently into my system and not be so noticed. Just a little boost in the lower registers that will add to my already accurate system. I am looking for an approaching lifelike sound from my set up while listening to jazz and classical and other acoustical vinyl recordings. What brands should I look at?