Rell or JL subwoofer?

Nobody mentioned MartinLogan X series. The go low, have full correction.

REL ain't what they once were. SpeakOns are a joke for sub connection. Don't believe a word of their malarky.

You need to mate sub performance to the mains.

A sub needs to have continuous phase control, polarity inversion, level and multi slope XO. If don't pass.

A long time ago, REL would be my first choice. Today, never except for the high end. Even then, they are more jewelry or furniture than speakers

I bought a Hsu ULS15 Mk II for music and am very pleased with it.  They told me that  if I played very low frequency organ music or would use it for movies, I should get a ported version such as the VTF3 Mk 5.  Hsu sells direct, so there is no middle man cost.

@soix  No my older SVS did not have the integration software.

@tcotruvo The ported VTF-3 MKV comes with 2 port plugs that can be inserted either one or both for Music or left open for cinema. These subs are very versatile.

I have a stereo pair of Rel 212's that I have been very happy with for a combination music/theatre setup that I ran with 802's.  I chose the 212's because I have a fairly large volume room and in my experience they are the best option overall for a combo setup.  Partly because of how I have them setup, I would say they are really good for 2 channel and good for movies.  If you are looking for a combo with smooth, tight bass I would seriously consider this model.  I recently changed to Focal Scala's and wound up adding a JL 113 V2 just for LFE.  In playing with the JL on setup I would say it is the standard for home theatre but I was not as happy with it in 2 channel vs the Rel's. 

Good luck...

I run a pair of REL T7/x for music.  Very pleased with them.

For HT, save yourself a bunch of money.  I'm surprised by an inexpensive Acoustech PL-200 II in my HT setup.

Rythmik and RSL Speedwoofers are some other lower-priced brands.  RSL are always sold out so that says something...