Where to begin...
If music is of primary concern, I also recommend upgrading to the Summits before worrying about the subwoofer. (I should note my setup is for both stereo music and HT). In my auditions of the Vantages, I noticed a rather easily detectable mid-bass suckout of sorts. This is a knock, but maybe my only real knock. Don't get me wrong, I still love these speakers. Even with this negative attribute, I found they did too many other things so incredibly well. So, I auditioned 25+ pairs of speakers from double digit brands, and I still chose these, and put a 20% deposit on some Vantages. No speaker is perfect, not the Summits, not anything as far as I am concerned. Anyways, in very large thanks to Kruppy, I now own Summits. I highly recommend installing a direct-line Batphone to Kruppy's residence, he found a Summit deal on Agon that might have sold for around 5.3k(?).
See, a top of the line subwoofer still won't help you much on the mid-bass. Ok, if you do not have this upgrade option:
The JL sub is a fantastic sub. Now, my perceptions of various subs, as always, were highly dependent on room setup. That being said, the JL provided the best transients of any sub I've heard, and is probably the most musical, possibly save for some REL units. (However, I do not enjoy the REL subs I heard in an HT setup). I also thought that the JL had as good, if not the best, pitch definition of any sub I heard. Of the sealed-servo controlled subs I heard, I thought the JL sounded better than both ML's and Velodynes, yet both costing less and coming in a smaller package.
Fwiw, I heard various JL subs matched only with Dynaudio speakers, including with a huge set of Evidence's. I did most of the auditioning with a pair of what I believe* were a pair of Contours (didn't care about speaker hunting anymore, very set on ML's, to the disappointment of the dealer). I've heard the Descent-i in two locations, both setup with Summits. The store where I more intently auditioned the Descent-i ... I don't think they had it setup too well. Very localizable with corner placement, and less defined or muddier than the JL for instance. Which brings us to...
the Room. I'm sure many will agree that the setup/placement can trump the actual unit being used. I know for a fact my room is presently an issue, and have been in a holding pattern about future purchases to deal with bass response, as well as frequency response for my mains, for both the trebles and the bass. I do not use the JL sub in a 2.1 music setup for now, but really look forward to further experimentation in the future, when I have the toys to allow me to do so.
Remember how I said no speaker is perfect? Even with the Summits, on very particular recordings, namely contrapuntal works on piano on a well-recorded disc, the timbral quality of bass lines do not match all of the upper lines. I really mean it when I say very particular recordings, and I do not notice this nearly as much on chamber works, or other recordings in general. I believe the piano is a tough nut to crack, because I don't think any other common instrument has such a balanced and consistent timbre throughout the range. My thoughts anyways. (I think the best timbral consistency throughout the entire range I've ever heard was on B&W's, but otoh, they don't do certain things nearly as well as the ML's). Why do I bother mentioning this? Because even though Im quite confident it is due to the hybrid design of the speaker, I also believe the room is negatively contributing in some way.
Anyways, a lot of opinionated blabber perhaps, but in a nutshell, I agree with Mr. Gordon Gray:
-If you can manage it, take that sub money and get yourself some Summits-
(I know, easier said than done, a good deal might have to be found. MSRP for the JL + Vantages is still thousands less then Summits).
*It seems that your only way of getting this JL is trading in your present sub. If this is not the case, and you can return it with no problems, I can PM you with what I found to be an excellent deal in TX. (Discovered after the aforementioned Dynaudio dealer did not want to budget from msrp).
