What ho, gents:
As promised, here's the reply I just received from Stan at Bryston. He confirmed that it is not
possible to set separate subwoofer distances when using the SP3's Aux-L/Aux-R outputs. As Tony (addino) mentioned, this is not a deal-breaker, but it does present some time-alignment issues and will require significant tweaking of the subs. In case it may be helpful to you, I've pasted in my query to Stan following his reply (and have attached a PDF of germane screenshots from my Velodyne subwoofers' software).
"I think, using Aux-L and Aux -R outputs to drive your two subwoofers will fulfill your goals 1-4. Aux-L and R contain downmixed spectrum from all the source channels in a multichannel stream, including the LFE. It will work equally well if the original stream is 2.0 or 2.1, 5.1 or 7.1. You have to enable a lowpass filter in your suboofers to be close to your main speaker's cutoff (about 39Hz). A time delay (speaker distances) cannot be independently set for the Aux-L and Aux-R.
Since your main speakers can reproduce bass from 39Hz up, you could set SP3 cutoff frequency at 40Hz and set SPEAKER SIZE as Small, or set them as Large and disregard the SP3 cutoff frequency setup. The only difference is that in the first case all bass below 40Hz plus LFE below 40Hz will be routed to the Subwoofer output of SP3 (which you probably won't use anyway), while in the second case only LFE will be routed to the Subwoofer output. In either case Aux-L and Aux-R will carry the entire spectrum, so there is no difference if you use only Aux-L,R to drive the subs.
There is a difference in the way bass contents of the L,R,C,Ls,Rs,Rb,Lb channels is handled as opposed to the bass content of LFE channel.
In the first case (Small) your main speakers will receive the portion of the bass from L,R,C,Ls,Rs,Rb,Lb above the cutoff frequency that you have set (40Hz) but none of the LFE, LFE will be all routed to the Sub only, along with the other bass below 40Hz, and all this will also be downmixed into Aux-L,R as well.
In the second case (Large) , All bass contents of the L,R,C,Ls,Rs,Rb,Lb channels will go through your Large speakers, regardless of the cutoff frequency set in SP3, while only all LFE will go through the subwoofer SP3 output (and will also be downmixed through Aux-L,R)."
I am writing on using two subwoofers with the SP3. I've read the manual but need your expertise and advice. A list of my gear appears below this message. I apologize for the length of this email; my subwoofers do present some perhaps unusual options.The goal
I want to enable stereo (or dual) subwoofer outputs (my subs are connected with in-wall single-ended RCA cables that I cannot change). As noted below, my subs can accept a full-range signal or an LFE signal; they can also be daisy-chained, to act as one sub. (I realize that at the lower frequencies, there is no stereo separation.)
1. How would I connect and switch the SP3 to use two subs when playing two-channel audio
2. How would I connect and switch the SP3 to use two subs when playing multi-channel audio
3. How would I connect and switch the SP3 to use two subs for LFE when playing multichannel movies?
4. Can I set the distance for each subwoofer individually?The question
Can I use the SP3's L-Aux and R-Aux outputs to achieve my four goals above? If not, is there another way to accomplish my goals?Pertinent Information
My Velodyne subs claim a frequency response of 14.6-120 Hz ± 3db, and my Paradigm S8 towers claim a response of 39 Hz - 45 kHz ± 2db. The subs have an eight-band auto and manual parametric EQ feature (screenshots below) that lets one adjust or bypass the low-pass crossover (high-pass is fixed at 80 Hz). The subs each have their own volume control. Velodyne's software will let me EQ each sub separately.
Also, the Velodyne DD15 prefers to use its internal crossovers rather than LFE output, but it will work with LFE if the low-pass crossover is defeated. Here are apt excerpts from the manual.A Word About Subwoofer Outputs
The Velodyne subwoofer is designed to operate using the full range audio signal for input when using the digital built-in crossover. Most processors/receivers have a “subwoofer out” jack that is internally filtered and designed to be used with a conventional amplifier and speaker. In some rare cases, combining both an external crossover and the one internal to the subwoofer may result in low output and increased noise. In these installations you may need to bypass the internal crossover in either the processor or Velodyne subwoofer. In some installations, simply setting one crossover to a higher frequency (such as 120Hz) will restore maximum performance. To bypass the subwoofer’s internal crossover when the unit is being fed a low pass signal from another crossover, refer to the SeTUP instructions at step 14 (page 24).Page 24:
NOTE: Some receivers/processors supply a signal that is already crossed over – i.e. just the bass frequencies. If this is the case, you will want to defeat the subwoofer’s low pass crossover. To defeat the low pass crossover, press the SelecT key, then the ReSeT key. The following screen appears:
[This screen appears in the attached PDF.]
Finally, if only one sub output is available from the SP3, I can daisy-chain the subs to act as one.A Word About Connecting More Than One Subwoofer
If you are connecting more than one dd subwoofer to your system, you will connect them together in a “daisy- chain.” choose one sub for all the connections described below (we’ll call this the “master” sub), and then connect an RCA jack from the THRU RCA jacks of the “primary” to the input jacks of the “slave” sub. You will also need to obtain a “mouse extension” serial cable (available at any computer store, from your Authorized Velodyne dealer, or from Velodyne directly) and connect the RS-232 OUT port of the primary sub to the RS-232 In port of the secondary sub. Then, all runtime commands directed at the primary sub (such as volume) will be communicated to the secondary sub automatically through the serial cable. If you have more than two subs in your setup, simply continue the daisy chain from the secondary sub to the next sub in the line (using both RcA and serial connections) and so on.
I very much appreciate your help, Mr. Bleszynski. I've been waiting a long time for the SP3 and am thrilled by its possibilities.Amplifiers
Bryston 6B-SST(C) amp: front L/C/R
Bryston 4B-SST(C) amp: surround L/C/R
Bryston 4B-SST(C) amp: rear L/C/RSpeakers
Paradigm Reference Signature S8: fronts L/R
Paradigm Reference Signature C5: front C
Paradigm Reference Signature ADP: surrounds L/R
Paradigm Reference Signature S4: rears L/R
Velodyne DD15 subwoofers (2): subwoofers L/R
Velodyne DD 2.2. Screenshots.pdf 435k .pdf file