Bassheads-DSP important????????Velodyne SMS??

Off my recent experience:

My personal formula (and ymmv) for good properly integrated, deep bass from a sub requires (in order of importance):

1) SMS-1. Will allow you to "see" your room above the range of the subs as well as properly integrate the subs and eq them. This is a huge advantage in getting successfully set up.

2) Room treatment. I "saw" the elevated response from 100hz to 150hz (+15 db at peak) with the SMS analyzer section. Two Bass Busters (tuned hemholz resonaters from Echo Busters -ATC has a similar product) later, I saw that this hump was gone. The improvement was dramatic and very audible through the midrange.

3) Sub of your choice. I use 2 Velodyne SPLR 8s, but A-goner Bob Reynolds has posted some amazing specs for the similarly priced (app $600 per) SVS subs that suggest they're a better choice if you're in a large room, listen very loud to organ music, or are thinking dual (home theater) use. BTW, Bob, Drew Eckhard, and Shadome are great resoiurces for bass/subwoofer questions.

Good Luck,

Marty

Chazz,

Musical subs are are about two things. Low Q (look for low group delay) and low distortion. Then it is only about power output - what do you need - decent LF power is very expensive.

The HT Shack subwoofer tests is a great resource. You will notice that low group delay tends to comes with a sealed box. The good ones tested are SVS PBultra sealed, JL F113 and teh Geneled 7073A. Genelec is expensive but has an impressive 5% THD at 20 HZ at 105 db SPL - given that in comparison to the JL, which has more than 20% distortion, one might conclude that the only audiophile music quality commercial sub they tested so far is the monster Genelec - at least of those they tested. The DIY TC Sounds LMS-5400 18" sealed 100L was the best oversall - I may be wrong but I think you are talking around $2000 for the driver alone and it is nolonger available to DIY'ers.

Note that low group delay seems to be important - my guess is that the REL subs despite their lousy distortion results are well liked because they have low group delay and a nice natural in room curve (rolls off at lower frequencies where room boost comes into play).

I think DSP is almost unavoidable for most rooms, unfortunately. Ideally you would like to have the perfect room with lots of acoustic treatment. I would advise to do the absolute maximum acoutic treatments you can BEFORE doing any DSP. DSP is never a good thing - so it should be used sparingly to tame extreme room modal peaks.

Your idea that small woofers are better than big woofers is not something that is supported by any test data.

Personally, I like the Velodyne Digitial Direct series that offers low distortion and a lot of power (class D) and can be automatically calibrated to your room or manually set using the suppplied connection cables to your TV so you can see peaks and dips.

I listen more to music than HT and sometimes I use the sub and sometimes not with music but when dialed in correctly, it is seemless with my 803D B&W's. I have the DD-12 (used to have the DD-15 but was a little much for music) and it performs both music and HT duties well in a 7.1 system.

For years, I put up with boomy, one-note bass from a Def Tech PF15 in my combo 2-channel/HT system. Thanks to this board, I have added both a Paradigm X30 sub controller (for level and phase adjustments) and a Behringer 1124P FBD Pro with parametric digital EQ. The results after tweeking the Behringer were dramatic. Properly used, notch filters can turn a mediocre sub into a good one.

That said, I have since added a pair of Vandersteen 2Wq subs to my system, to augment the mains (Vandy 1C). What I have learned from this upgrade is that if you start with a good design, DSP or notch filtering is not as critical. With these subs (which have adjustable Q), blending with the mains (at least in my case) was easy and seamless. Bass is quick, taught, musical and powerful. There is no bloat, boom or sense that the sub is there at all; everything seems to come from the mains. These subs sit in corners (they are designed to be placed in corners), and my room is pretty lousy from an acoustic standpoint. Again, the difference is in the engineering. Richard Vandersteen looked at how most consumers will use a subwoofer, and designed it appropriately. More than just putting a big cone and an amp in a box. That's my $0.02 - YMMV.

I just want to add to Shadorne's reply about small vs. big woofers. I've played bass guitar professionally, and what I've noticed is that while small woofers may give you more resolution of the notes, its always the big woofers that give you the slam and visceral "feel of electric basses, as well as more of the body of the upright bass or cello, or the low pedal notes on an organ. Velodynes use an accelerometer to control the woofer, which can give you better "control" of a woofer's timing, thereby not hanging on to the notes too long. Shadorne is correct that room treatment may get you farther than DSP where bass is concerned.A compromise may be to use a ten inch woofer rather than an eight or a twelve. Hope some of this helps--Mrmitch