Best Subwoofer you've ever heard???

Some speakers need it.Unless you have something so pure you don't want to screw it up (I was thinking a narrow range system like 47 Labs Essence I heard once).Some folks love their Quads or Maggies but their strengths mean seamless integration is tough and more has been written about those two speakers than any.Sure if you want HT 'Boom In Room" try a Velodyne 1812 (JL is a good large sub and price pint wise better than ginant Velodyne).But for music is you want to hear below low note on an electric bass (40Hrz) and have quality then go for a multi driver (usually 3) not larger than 6" or 8maybe 10" as they as rule are faster and give better pitch definition.Some names like REL,MJ Acoustics (employee spin off of REL).Electronics help so adding EQ SMS-1 helps or like Thiel where you don't have 18" driver with enormous magnets.If you have a nice two way which just can't get down their a sub can add but with best systems it's a trade off it's just that some people want to hear and feel Organ music or such down to low 20's.I have heard some great horns with them.One that is a single driver with fast light pitch accurate footprint is Magellan TBI which I know one guy with Avantgarde swapped larger much more expensive subs made by Avantgarde themselves.He loved them.One other 'Gonner I read made a Fostex and ribbon dipole and put a number of subs into his floor joists and linked them all up with a DEQX electronic crossover to control all drivers.I wished I heard that.Sometimes they work.If someone thinks they might have a hybrid two way of quality and wants HT in same Martin Logan Depth is a 3 8" multi driver that with an EQ is great but not as refined as REL which has been 2 channel fave for years at a sane price.Now they have revamped their line and to get original designs you need to buy two top end Stentor and Stadium.This is from what I have heard and read.So they can work but if you can be satisfied with what you can get out of two boxes all things being equal that is better.
Chazz

Vandersteen subwoofers are one of the best I have used and they have a unique way of integrating with your main speakers. Maybe not the deepest bass, but deep enough and very musical. Highly recommended for music with three eight inch drivers in a slot loaded cabinet.

JL Audio only offers a line in connection, so if you need a different type of connection you are out of luck. Also, the input impedance, which is very low, may cause a problem for some systems.

In all things audio there is always a trade off and as was mentioned in a previous post, sometimes the best sub is no sub at all.

The JL F113 is the best sub I have ever owned but if you want more spl for movies then multiples are in order.

In the majority of rooms you are going to get the best response at the LP with multiple subs rather than one. If cost is a concern I would rather go with a good quality pair of $1,500 subs than a single high quality $3K sub as distortion will be reduced and room modes will be easier to tame resulting in better SQ.

Bottom unit of the K-Horn. I know two people who use them that way.