Best subwoofer?

Considering the Meridian front end viz G68/98 with my atc.Unsure between the Revel ultima and atc sub(C6) and velodyne DD18.Have a pair of ATC 150 asl pro.Thoughts?Also have a VSEI modded Sony scd-1(presently getting the 5.5 mod)
I like Martin Logan's Descent sub. very muscial with strong bass responce.
Thanx for the response.
please try Audio Physic's Subwoofer, they are too good to notice their existence.

audiobahn all the way
I am very happy with my Vandersteen SW2 sub. I am sure for more money you can get a better sub but not perhaps better value. Also what is important is how the sub intergrates with the main speakers. Having the best rated won't always work out.
I found that Wilson Audio's demo of the Genelec at last years CES was pretty telling of what you get for the money! Actully don't take my word for it go to Wilson's website under news and views and see for yourself what's actually inside a Genelec vs a Wilson Watch dog VERY SCARY what some manufactures slap together and call it ground breaking or cutting edge !. I don't own a Wilson watch dog or anything i just thought it was a very effective demo.
Revel Sub 30, one of the best. you owe it to yourself to ck this sub out. gets down low. great for music as well as HT
For High-End stereo, try a REL Studio - Its the best out there. Any REL really. Especially the "ST" range.
The REL Studio comes in three generations I, II and III (Linkwitz Riley, ARM and Super ARM loading). Has anyone managed to compare them, ie, is there a significant improvement to consider getting the later generation model? I'm considering to use one with the Apogee Diva's, where both speed and musicality are important.
Perhaps, you should have stated some constraints with respect to your question, such as size weight and cost. This is from the perspective that the best subs out there are very large (as a minimum, think 3' by 4' by 5'), generally well braced and massive (300-500# per side) and very expensive ($10-20k per sub). That is not to say that there are not good choices at other price points and with smaller size. Of the subs mentioned, I would recommend either the larger Audio Physics subs or the Martin Logan Descents. I have had very positive experiences with both, albeit in other audiophiles systems. I have also heard good things about the digital Velodyne self equalizing units but have no personal experience.
Any REL.
I have owned dual decents, many velodynes, HSU ,JM labs many many others and by far the best bass you can get is not with the compramised sub woofer designs but from a true bass system. Subwoofers are flawed in design from the start, you need massive power, large excursion drivers, subs need room and boundery reinforcement to produce deep bass. A bass system uses low excursion drivers can run on low power isnt effect much by the room. These designs can be horn loaded, BR, TL or even OB its only weakness is size and costs. But with what decents cost or REL. You could get real lifelike bass large excursion drivers cant reveil these small details like low excursion can, the details are lost to the massive forward backward movements these sub drivers produce.Why so many folks with great loudspeakers find subs to be very hard to integrate.Toss in room nulls and peaks that one must work with when subs are used its amazing to me that anyone can enjoy such sound. But as always YMMV
if you need a sub for a stereo system, the only one I have listened to which is fast enough to integrate with a <=9" woofer is the Wilson Benesch Torus
I have 2 Rel Stadium III's, they sound great with HT, one front & one rear. I use them for LFE input only. I too use a Meridian G68/598 for my HT.
I purchased an Aereal Acoustics SW12 because I wanted more flexability, like high & low pass filters & an EQ for my 2 channel analog setup. It intergrated flawlessly with my front speakers. I will try it with my HT later after I get a second one.
Any REL sub!
SVS The very best for the money! SVS subs blow away any sub costing three times as much!
The best that I have heard are the Cabasse Saturn 55 Active Subwoofers which are hideously expensive. A 21" concave Cabasse woofer (built in their factory) in a 37" by 33" by 28" box with a 1200 watt amp, parametric EQ and low pass filter, capable of generating 135.5 db at 1 meter. 350# per side, massive and inert. I had used these in the past with a pair of Acapella Campanile speakers with mixed results (the bottom octave was fabulous but they never mated perfectly with the Campaniles. Two weeks ago, I set up a pair of Acapella Triolons in my system which use a horn loaded 12" woofer to cover the range from 170-700 hz rather than multiple 10" SEAS drivers in an acoustic suspension enclosure). For whatever reason, the mating is seamless with the subs crossed at 40 hz. Normally you do not realize that these are in the system, except for an increase in low level ambient information and air and a concommitant increase in the volume of the sound stage, particularly with respect to depth.
However, when low bass exists, the response can be awsome. Are these really the best subs? Who really knows? What I do know is that they are by quite a margin the best that I have heard when used properly in the right system.
The Legacy LF Extreme with Level, Freq, Blend and Phase controls makes for effortless integration and the 15in drivers let you into the basement for low bass and depth.
Take a listen to the REL Britannia B1 sub; it has the extra punch needed for great LFE effects for home theater with the finesse of the traditional REL subs and ability to blend off your main amp terminals for 2-channel.

I also utilize a Velodyne SMS-1 digital drive processor for LFE parametric EQ. The combo of this and the REL B1 for home theater is quite compelling.
SVS PB13 Ultra and call it a day.
Really like the jl phantom 113, is costly though but really delivers the BASS!!!!!
I integrated DD-18 with my B&W N802. Room problem was at 46 and 63Hz, so no other subwoofer will provide such precise equalizing as Velodyne. Only problem with DD is 1/3okt measurement, but I done it with other 1/24okt software. Anyway, it took allot of time, but on the end, you have flat in room response down to 14Hz!