Subwoofer for 2 channel high resolution system


What sub is suitable for music. Would like something that would mate well with a system that is transparent portraying excellent sound staging and imaging.
Basically I am looking for a first rate sub for music. One that will disappear, but add the bottom that will take my system up a notch.
Also need balanced i/o, and a high pass to amplifier.
pedrillo
Which sub's are of higher caliber? Wilson Benesch, JL fathom, REL, Velodyne, Revel, Kharma, Martin Logan, Paradigm, Sonus Faber, NHT, Wilson Audio, JBL, HSU, B&W, JM Labs, Tyler Acoustics, Von Schweikert, Avantgarde.
Which ones are the fastest and natural sounding?
From what the mags have been saying the JL Fathom's seem to be the ones- do audiogoners agree? If so what else is in that league?
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Bob is right. You need to test drive some of the subs you listed. I tried Velodyne and B&W before a ended up with a Rel. The Rel just blended with my room/system better(even though I run B&W speakers). Good luck!