Do you think you need a subwoofer?

Hi enginedr1960,

     I agree with you completely, there really are many ways to achieve great sound.  I'm very impressed with the home-made distributed bass array system you created with your 4 Rel q201e compact subs and other components.

     I've been assuming you have no need for your Bent passive Dave Slagle autoformer volume control and Minidsp 2 x 4 simply because I use no such tools in my system and it functions beautifully.  I admit my comments were made without a complete understanding of these products and how you utilize them in your system.
     I took your suggestion and did some research on the Bent passive volume control, the TAP system and the Dave Slagle Singleformer modules.  This seems to me to be a seriously high quality product/system and, if this is any indication, you obviously choose your system components carefully.  I believe you use this to control the volume and balance of your 2 front Rel subs via an optional remote.   I believe you use the Minidsp 2 x 4 units to control your 2 rear subs and perhaps even some room correction..

     As you can see from the above, I only have a partial understanding of exactly how you use these products in your custom DBA  system.

     However, I'm sincerely interested in learning more about how you utilize these products in your system.  I think sharing exactly how our DBS systems are configured would be a good way to learn from each other and could be mutually beneficial.  I hope you agree but please let me know if you don't.

     Okay, I'll go first.  I think you'll find my system is a bit simpler than yours since I made a conscious effort to simplify my system about 2 yrs ago and I don't use any additional components:

     The center of my system is the Oppo-105 Bluray player. Once I was familiar with this unit's extensive versatility and excellent quality, I began to simplify.  I removed my beloved VTL 2.5 tube preamp (with NOS Mullard tubes)  because 2-ch music sounded just as sweet and dimensional using the Oppo alone as a preamp due to its excellent audio section.  I then removed my Parasound AV-2500 surround processor because the Oppo's built in Dolby 5.1 decoder performed just as well.  All channel outputs are run directly into  4 class D amps (the front L+R mains via XLR cables and all others via RCA).  

     I bought the audio Kinesis 4 sub Debra distributed bass array system a few months after the Oppo.  I run an RCA cable (with a single RCA connector on one end and dual RCA connectors on the other end)   from the single sub output on the Oppo to the L+R inputs on the Debra's supplied 1,000 watt class A/B sub amp.

      This amp is a mono amp so all 4 4 ohm subs operate in mono mode in my system.  I found I cannot perceive any differences between mono and stereo bass until the bass crossover frequency is set unusually high ( above about 150 hertz).
      The supplied sub amp has 'A' and 'B' sets of speaker outputs.  I have the front 2 subs connected in parallel to the 'A' terminals and the rear 2 subs connected in parallel to the 'B' terminals.

     The Oppo has a configuration menu that allows for the on-screen setup of the following:

Speaker Size- Each speaker is entered as either 'Small' or 'Large'. All 'Small" designated speakers have their bass augmented from the subs while all designated as 'Large' receive no bass augmentation.

 Speaker Level Matching- This allows the matching of each channel's relative volume or setting to other preferred levels.  A system generated tone is played and the user cycles through each channel. The Speaker Size (large or small), speaker volume (from -10.00 db to +10.00 db in increments of .5 db), and distance from the listening position (from 0 to 60 ft in .25 ft increments for delays) are all set in this section.
    This Speaker Level Matching section also includes settings for the relative volume of the bass in this section.  There is also a volume control on the Debra amp that can be manually adjusted for fine tuning the desired bass level of the 4 subs. 

Sub crossover frequency- This allows the setting of a frequency (from 40 to 250 hertz in increments of 10 hertz) at which all bass frequencies at or below this hertz number are sent to the subs. I usually select a 40 hertz cutoff for 2-ch music and ia bit higher for HT.

     After completing the rather extensive progressive setup procedure for the precise  positioning of each sub, the above describes the total extent of system configuration required.  I use absolutely no room treatments, microphones, sound meters, room analyzing/correcting software, DSP, tone controls or equalizers.  
     The system Master Volume is controlled through the Oppo's internal 32 bit digital volume control that is accessible either through the Oppo's front panel or supplied remote. I doubt this volume control is as precise as the 1 db changes  the Bent volume control is capable of but it is capable of small changes in volume.  
    I hope this helped you understand how relatively simply my system functions.  
     Please let me know your thoughts and let me know in more detail how your system functions.

   Thanks,
    Tim 
 

Hi enginedr1960,

     It sounds like you have a combo system, as I do, used for both music and HT.  I was a bit surprised you use VTL 100 mono-block amps in your system.  I would imagine they're great for music but less than ideal for HT since tube wear is increased.  Or, do you have your system configured to utilize separate solid-state amps for HT duties.  Could you clarify this?

     
     I understand how your Outlaw pre-pro is used for decoding surround sound codecs for HT.  But I'm not certain how you utilize the DSPeaker antimode 2.0 and exactly what it does.  Could you explain in more detail how your DSP controlled stereo bass works?  

     I've been trying to spread the word on distributed bass arrays using 4 subs here on Audiogon ever since I personally discovered how well it has improved bass reproduction in my system.  After a lot of research, I intellectually understand the acoustical physics and the theories on how and why it works.  But I still think there is no substitute for auditioning a good DBA in person for appreciating how impressively it reproduces bass in any room without the use of mics, room analyzing/room correcting software, equalizers or room treatments.  

     Based on the large number of posts I've read from members who seem to think their system bass response needs can be solved if they just get the right brand or model of sub, it's fairly obvious that many are unaware of the DBA concept.
     You're actually one of the first Audiogon members I've encountered thus far that also utilizes  a DBA.  I'm glad we're now aware we both use slightly different DBAs and can share experiences and information with each other.

Thanks,
  Tim 

Hi Tim I use the VTL 100 amps for HT and 2 channel music . as for tube life I am using 2 KT120 tubes in each amp if they wear out so be it . There is plenty more of them available . I use the DSPeaker as a room correction for 500hrz and down for the main speaker and all 4 subs . This device works by using a microphone to measure the room response from the listening area then it runs a series of tones across the L/f range and applies a correction . I have frequency bump @  50hrz and the DSPeaker corrects that . The biggest improvement with adding the 2 extra subs is that the bass response all through out the room is much more even and the tonal quality is better. RC      

Hi Doc,

     I like your commitment to all out sound quality by using your tube VTL 100s for both 2 channel and HT.  I just have a few questions:

1. Have you tried lowering the sub crossover frequency  closer to the 50 hz lower frequency cutoff on your amps?

 DSPeaker room correction for 500 hz  and down seems somewhat high and broad to me.  I consider 500 hz to be in the lower mid-range spectrum rather than the bass spectrum.  

2. Have you tried running your system with all room correction units removed?

I think you'll find your system's bass response will be very good without it.  I would recommend setting each of your sub's crossover setting initially at 60 hz and then experimenting with even lower settings of 50 or even 40 hz.  A setting of 50 hz may not be good in your room due to your room having a frequency bump @  50 hz.  The downsize of this approach is that the level and cutoff freq. would need to be set individually for each sub.  But this should only need to be done once at the precise setup/calibration stage.

Thanks,
  Tim