High end Subwoofer question


I have recently stated to experiement with dual subwoofers in my system. So far, alot of fun and quite interesting. The question I'm asking you GON members is:

Based on your experiences how important is it to get a Subwoofer, regardless of the brand, that has the built in feature were the sub is first optimized for the room using a microphone were you have your listening chair and the sub uses a series of test tones to load the room correctly. I fully realize that you must fine tune by ear the crossover point and volume of the sub by ear. So, is this room optimization feature a marketing gimmick or really a terrific help in dailing in a pair of subwoofers for maximum performance? Any feedback will be greatly appreciated.
teajay
Personally, I'd rather have a first rate sub controller (including room analyzer and Parametric EQ) than first rate subwoofers. Halfway decent subs, properly crossed and eq'd can sound very, very good. Great subs, poorly crossed, still sound wrong. Just MHO.

Marty

BTW I use a Velodyne SMS-1 controller, which will work with any sub. It's terrific and costs $400-$500 on-line. SVS makes an Audyssey driven EQ that will ship in May at app. $700. This will require a separate X-over like the NHT X-2, so total cost is closer to $1K. No one's heard one yet, but Audyssey technology is very good and this approach will allow you to low-cut your main speakers without A/D/A conversion. I'm sure that there are many other options out there. Good Luck.
My experience: My first subwoofer was a Def Tech PF15. This is a typical, boomy, sealed design. Although I lacked funds to buy an expensive DSP device, I did invest in a Behringer FBDP 1124P parametric digital EQ. Following instructions I found on the web, a test DVD with frequency sweeps (Avia Guide to Home Theater), and a Radio Shack SPL meter, I did a good job of smoothing out the response. It is time consuming, especially if you use a computer to determine your level adjustments, which I did. In order to increase the gain for the sub, I also added a Paradigm PDR-30 sub controller, which adds 14 dB of gain and, importantly, a phase control (no phase control on the PF 15). While the results were an improvement, these adjustments could not make the PF15 "faster" or more "musical." The peaks were now reduced, but I cannot hear bass below about 26 Hz, even though the SPL meter indicates solid output to 20Hz. Could be my room or my ears; not sure.

I knew better bass was out there to be had, and I waited patiently for local A'gon sellers to offer a pair of Vandersteen V2q subs. I figured they'd mate well with my Vandy 1C mains. These are very unconventional in design. Visit the Vandy site - www.vandersteen.com - for details. Richard Vandersteen told me personally that these subs are designed to have a pretty flat in-room response to 22Hz when placed in the room's corners. Also noteworthy is the requirement to determine your amp's impedance. Using the *temporary* adjustable outboard x-over, you determine the optimal crossover settings. Once determined, you must order in-line x-overs from a Vandersteen dealer (~$125/pr). The temporary x-over is NOT transparent. I procrastinated in ordering the permanent filters. That was a mistake. With the in-line filters, the sound, especially the stereo imaging, improved dramatically. Without any signal processing (aside from the inline filters), the bass I get now is tight, deep, tuneful and accurate. That last point is very important. Unlike some subs, these dissappear unless they have a signal to reproduce. Then, you hear the bass, but not as booms from a subwoofer. The bass integrates perfectly with the mains. There is no sense of a subwoofer per se, but only of the mains reaching really deep for bass you can feel. Note that this is only the case when the source material contains deep bass, which is, IMO, as it should be.

These subs list for $1400 each, plus the filters, but can be found used for under $900 here on the 'gon from time to time.

I feel this is a clear case of good design trumping aftermarket fixes and tweeks. YMMV

Oh, the Def Tech? It's still there, doing LFE and bass duties for the center/surround/back channels of my combo 2-channel/HT rig.
Since you can do this with Room EQ Wizard or another software I'd say it is more important to choose a high quality sub than to go for features. Many subwoofers are nothing more than excellent harmonic distortion generators.
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I'd agree with Bob and Shadorne that many subs (including mine) generate scary levels of distortion. I only question whether you can hear it at these frequencies. I've auditioned the lower distortion JL subs pretty extensively - different rooms, different systems - and can't honestly say that I can hear much difference. I'll eventually replace my subs with better performers (mostly on principle), but I do question how much benefit I will hear. Caveat: You & others may well hear stuff that I don't.

As to Room EQ Wizard, it's a useful tool for analyzing bass anomalies in a room, but my version was a bit of a pain to use. I found the SMS superior and it also offers really effective PEq and crossover functions. Caveat - my version of Room EQ Wizard was -as I understand it- a custom package based on the same shareware algorithm as REQW, but as modified by a local recording studio. Therefore some of my issues may be unique to the specific package I was using.

Marty
Dear Teajay: +++ " How important... " +++++

here are what is my opinion and experience about:

http://forum.audiogon.com/cgi-bin/fr.pl?eanlg&1117893153&openflup&27&4#27

http://forum.audiogon.com/cgi-bin/fr.pl?eanlg&1117893153&openflup&31&4#31

http://forum.audiogon.com/cgi-bin/fr.pl?eanlg&1117893153&openflup&47&4#47

http://forum.audiogon.com/cgi-bin/fr.pl?eanlg&1117893153&openflup&63&4#63

http://forum.audiogon.com/cgi-bin/fr.pl?eanlg&1117893153&openflup&68&4#68

http://forum.audiogon.com/cgi-bin/fr.pl?eanlg&1117893153&openflup&75&4#75

http://forum.audiogon.com/cgi-bin/fr.pl?eanlg&1117893153&openflup&84&4#84

http://forum.audiogon.com/cgi-bin/fr.pl?eanlg&1117893153&openflup&158&4#158

http://forum.audiogon.com/cgi-bin/fr.pl?eanlg&1117893153&openflup&196&4#196

I hope could help to put an additional " light " on the subject.

Regards and enjoy the music.
Raul.
I have a Velodyne DD-15 that has the EQ feature that also displays the EQ and frequency curve on your TV and allows you to test various phase, polarity, contours, volumes etc to blend with your mains. It would have been very difficult for me to have done it by ear alone and the mic and software is very accurate.

You can do the set-up for each of 6 presets (ie, music or action movies) which I find useful and for say music set the servo to produce the least amount of distortion.

After this is done, you can also put on a music or movie source and let your ear be the guide to 'is it seemless?' and still watch the frequency curve on your tv and do any tweaking.

While all this took a while, it was productive in the end. Needless to say, I like the DD Velodyne Series. The DD-15 and DD-18 have the least distortion.

And to answer you question directly, its internally EQ and other set-up features that yuo can see on you TV were invaluable.
Another quick note:

The Velodyne SMS I mentioned is a stand-alone version of the controller embedded in the DD subs described by Nick, above. I use the presets for different main speakers. Maggie SMGs are preset #1, Ohm 100s are preset #2, etc. If you rotate speakers with your subs, it's a great convenience.

Marty