Do you think you need a subwoofer?

enginedr1960,


Congratulations, I'm glad the distributed bass array system works as well in your room as it does in mine.  I'm not really surprised since this method has been proven to work in numerous rooms no matter the size or shape.

But, if you don't mind, could you give us a few details such as:

Are the 2 additional subs you added the same brand and model as your original 2 subs?
Are your subs self amplified or passive (driven by separate amp(s))?
What method did you use to locate the subs in your room?
Where did you windup locating the 4 subs in your room?
Do you use your system for 2-ch music, HT or both?

     I think I've stated my system is used for both 2 ch music and HT and, just as you stated, "the whole system just sounds right" for both.  I still find I'm amazed how well the distributed bass array system works and with absolutely no room treatments, microphones, software programs or equalizers required.
     I know the distributed bass array system is scientifically based and has been empirically verified by numerous independent acoustic engineers and users but I'm still amazed how well it works.  Taut, powerful and textured bass that integrates seamlessly and just sounds life-like and right.

Thanks,
   Tim

I've resisted using a subwoofer (or really a woofer based system, not really a "subwoofer" per se) with my Sound Lab 845PX speakers for several years.  The reasons for my recalcitrance are as follows:
(1) I've never met an electronic crossover that did not color the sound in some objectionable and noticeable way.
(2) I am getting tremendous low bass response from my 845PXs with no added woofer (but see below).
(3) I ascribe to the idea that one-way systems are a virtue; I have revised the electronics in my 845PXs to eliminate the filtering that precedes the two audio step-up transformers. (This is another long story not suitable to this thread.)  There is no crossover in my system anywhere and only one 0.1uF capacitor in the signal path, from the line level input of the preamplifier to the speakers. 
(4) I envisioned that adding a woofer system would require introducing at least two large-ish and probably ugly cabinets into our living room, and I am or was loathe to do that. Esthetics matter to me.

However, the price I pay for this policy is in fact that I have too much bass.  I do perceive suboptimal resolution and definition at the extreme lowest frequencies, where there is not so much a "peak" but a gradual rise in speaker output.  I use Tube Traps behind each SL panel to ameliorate this problem, but it is not a perfect solution. I believe this is because the SL speakers rise in impedance as frequency goes down.  (I've measured this.) Since I use OTL tube amplifiers, this results in a broad rise in speaker output, inversely related to frequency. (The OTLs love high impedance.)  Lately, I perceive there are ways to overcome my reservations about electronic crossovers, either by using only a capacitor at the amplifier input, to roll off the 845PXs at low frequency, or by using any of a very few electronic crossovers that may be acceptable to me.  In addition, one of you guys pointed out that a pair of woofers could be placed behind the panels, out of sight, and that the cabinets need not be huge.

Over the years, I have made this system better and better.  Now I think the only thing left is to take a shot at adding a woofer supplement.  Duke LeJeune probably knows more about supplementing SL speakers than anyone, and I intend to consult with Duke on the best course of action.

To clear up my system and crossover implementation I use a cap in the signal input to my VTL100 tube mono blocks to make a high pass @ 50 hrz . and use the Mini DSP 2x4 as the sub only crossover that I can adjust on the fly . The extra subs serve as active room treatment

lewn,

   As you are well aware, the Sound Lab 845Pxs are excellent speakers that are capable of going fairly deep (26 hz).  However,  I believe a distributive bass arrray (DBA) would be a very good solution in your system for several reasons:

1.  The bass produced by a DBA, using 4 10" driver subs, will be seamlessly integrated into the sound coming from your sound Labs; capable of being as quick and detailed as the Sound Labs or deeper and more powerful depending on the source content.  

2.  Using a DBA will relieve your OTL amps and the Sound Labs from reproducing the more demanding lowest frequencies., the supplied separate class A/B amp would be powering the bass (if you go with the Audio Kinesis Swarm or Debra DBA) or the internal class D amps on the mini-subs would be powering the bass (if you go with the Rel q201e subs that enginedr1960 uses).  You could then turn down the bass level to taste on the Sound Labs.  I think the result would be even better performance from the Sound Labs (especially in increased dynamics) since your OTL amp would mainly be powering the mid-range and treble with bass level powering reduced by the amount you determine sounds best.

3.  Using a DBA as described above will significantly reduce the amount of crossover circuitry in your system's signal path.  There would only be crossover circuitry in the bass level that is built into both the Audio Kinesis separate amp or each individual powered sub.  
      You would customize the bass to your preference by a combination of reducing the bass output level on your Sound Labs and adjusting the crossover frequency and volume setting on the Audio Kinesis DBA separate amp or each individual powered mini sub.  A bit cumbersome but it would provide great flexibility in dialing in the bass to your exact preferences.

4  Room aesthetics would be minimally affected. I replied to you in an earlier post about this.  
     Basically, I described how my 2 front subs are hidden behind my 2ft wide panel speakers and the other 2 (each along a side wall near a back wall) are partially hidden by a leather chair and an oversized end table.
      My room is 23ft x 16ft with an 8ft ceiling and I barely notice them.  I think your room may be even larger.  Your panels are also even wider at 3ft so, as long as you determined through the setup process the subs sound best at those positions, they would be completely hidden from view.  That just leaves the rear 2 subs that need to be creatively hidden.


   Just my thoughts but I really believe a DBA would be a great sonic match with your Sound Labs.

Tim