Choosing Sub-woofers. Please advise ASAP.

akg-ca,

     I enjoyed reading your post on the Vandersteen 2Wq sub system  and I think it could be a very good bass system with a few modifications.  I especially like the subs taking their signal from the main amp in order to better integrate the overall sound with the main speakers..  Your post states:

" It is for all of the above reasons that there is only one subwoofer in existence capable of integrating seamlessly into a high-end music system, allowing you to reap all of the benefits of having a subwoofer, with none of the drawbacks."

       In order for this statement to be true, however, I believe the Vandersteen system would need to utilize 4 2Wq subs and utilize a much more precise distributed array method for locating each sub.  There was no mention of where to place their subs and simply placing them at convenient locations in the room will inevitably result in uneven bass performance throughout any given room.
       The only currently proven method to eliminate bass peaks, nulls and standing waves (providing accurate and even bass response throughout the entire area) in any given room is to use a minimum of 3 subs, ideally 4 subs, with each sub positioned according to the distributed bass array procedure.  
     I think the Vandersteen 2Wq system, with 4 subs and setup in the distributed bass array method, could perform equally as well or possibly even better than the Swarm or Debra bass systems.

Thanks,
 Tim  

          

I have Vandersteen Treo's.  I believe I just sold them and I'll be getting the Quatro's.  Why?  The subs are built in and they have an 11 channel EQ.  I have yet to hear any sub that sounds as good IRT musicality.  They will shake the room.  That said, he's also making a sub that matches with the 7 mk2's.  It's not cheap, but it's special.  Richard will tell you that if you want to move as much air as possibly, that you can just add a sub to each channel, including the surrounds.  

"Your speakers are pretty full range so you’ll need 12 inch or larger to extend lower if needed at all. Two are better than one for balance across the room."

I would think the exact revese to be true. A full range speaker should sound better with a smaller sub by virtue of its FR and the fact that it’s producing decent bass on its own already. Conversely, a small speaker should benefit from a bigger sub to cover a wider range.

"A full range speaker should sound better with a smaller sub by virtue of its FR and the fact that it’s producing decent bass on its own already. Conversely, a small speaker should benefit from a bigger sub to cover a wider range."

It doesn’t work that way. Here’s the "old school" principles:

Smaller woofers/subs are TYPICALLY more limited in extreme low frequency output than larger woofers/subs. Since the presumption is that the OP has "full range" speakers already and wishes to further enhance the ultra-low bass output of his system, the larger woofer/sub SHOULD go lower, providing more ultra-low frequency enhancement, all things being equal.

Further, if the OPs "full range" speakers already have a strong mid/upper-low frequency output, adding a smaller (higher frequency output) woofer/sub will create boominess in that range (major overlap in the midbass). Worst of all worlds IME.

Conversely, a smaller woofer/sub should TYPICALLY be quicker and more tuneful in the mid/upper-low bass frequencies, thus easier to integrate with a "smaller" speaker, assuming that the latter’s low frequency output rolls off a significantly higher frequency than a "full range" speaker (minor mid/upper-low frequency overlap of the smaller speaker with the smaller sub’s higher output frequency). Ultra-low bass will not be enhanced as with the larger woofer/sub, but that is irrelevant if integration is poor.

Many potential exceptions to this are experienced in the real world as it depends heavily on the cabinet size/design of the sub, crossover adjustment flexibility, design (ported vs sealed), amplifier’s power/characteristics/ability to control the woofer, and placement. Also the newer concept of digital room equalization/correction built into the sub’s digital electronics (a’ la’ JL Audio and a few others) negates the "old school" rules to some extent, allowing a larger woofer/sub to integrate well even with smaller main speakers by tuning/contouring the sub’s output (increasing or reducing the output at certain frequencies based on system characteristics/room acoustics as measured by a microphone and processed by the sub’s digital circuitry).

Subs can also be used for entirely different purposes than "bass enhancement". I use two REL Stadium III sub’s fed via the high level inputs from my amp with the subs’ crossovers set to "out-of-phase" mode to cancel standing waves due to room bass nodes, actually reducing the perceived bass heard at my listening position, and to enhance the soundstage (by loading the room with sound pressure from the subs) as my main speakers need no low-bass enhancement, but actually the opposite in my room. Works quite well.

Dave

  Dave,

     Very interesting how you're utilizing your 2 REL subs set to 'out of phase' to reduce bass standing waves in your room.  I haven't heard of this  before.  

     You state that this has actually reduced the perceived bass at your listening position but, due to the subs loading your room with low frequency sound pressure and your mains ability to go deep, this has resulted in an enhanced soundstage at your listening position.  

     I'm not completely clear on this but, since it's working so well for you, I want to learn more about this method.  A few questions if you don't mind:

1. How did you decide where to position  your subs, through a set procedure or trial and error?

2.  Can you be more specific concerning the sound qualities that result in your perception that the soundstage  being enhanced?

3.. Did you set it up so bass is best at your listening position, or so bass is good throughout the entire room?  

Thanks,
  Tim