Musical subwoofer under $2000

+1 @yyzsantabarbara 

The KC62 was recommended to me for its speed or ability to keep up with my main speakers.  It’s the only sub I’ve tried, and I am very satisfied with it.

Subjectively, I like the KC 62’s size and industrial design.  And, while I couldn’t say so based on direct experience, others who have vast subwoofer experience and expertise have posted that small rooms do very well with small subs for 2C listening.  To be clear, I’m declaring my room small, not the OP’s.

Not sure if it’s been said, but SVS has a model that competes with the KC62 for less money.  John Darko compared them to each other on YT.  

Good luck

Please look at the Dynadio 18s

Goes down well bellow 30hz and is very musical

+1 for the Rythmik F12G.  That's what I paired my Magnepan MMGs with (very, very well I might add). 

I later added a small M&K K-10 in an opposing corner just for kicks to help fill out the room.

The Rythmik subs are highly adjustable, appear to be about as fast as any sub on the market and IMO offer all the slam anyone could need regardless of music.  I don't understand the comment on Rythmik subs not being good for rock slam.  They'll eat pipe organ lows for lunch and drink rock slam as an aperitif, near as I can tell. 

YMMV.

I am critical of subwoofers and most recently  owned two REL T9i units. 

The RELs sounded excellent but had a couple flaws that made me sell them. The level control was too coarse for properly matching with my main speakers- one click position and the sub overpowered the main speakers and on the lower click the output dropped too low for some reason.  

They did not extend at the sub bass frequencies which is something I prefer- a strong output at 20Hz. 

My new subs are the SVS SB 2000 Pro.  They have excellent output and 20 Hz and give that deep bass sound and feel.  The App control is very fine- level setting and matching is easy.  The DSP is also useful, I used it to tame a few high peaks on the left subwoofer to smooth the response. 

If you have room, the SVS SB3000 is super impressive and has a bit better tone than the SB 2000 Pro.  The SB 3000s were too large for my space.