Possible to share L+R and sub(s) between stereo and AVR?

[Epos7]

I recently ordered a Denon X3700 and would like to use the L + R pre outs in an effort to share speakers and subwoofer(s) between several stereo sources and the AVR.

I'm imagining the X3700 L + R pre outs going to a preamp with input switching. Something like the Topping Pre90 would allow switching from the AVR to a DAC or record player. The safe volume feature of the Topping might allow for the AVR input volume to always remain consistent, allowing control of the L + R volume from the AVR, though I'm not entirely clear on how that feature works.

So while it seems possible to share the L + R speakers in this manner, I'm unsure if it would be possible to share the subwoofer(s). I imagine the only possible solution might involve input switching on the sub(s) itself?

My ideal would be a 3.1 or 3.2 system where the L + R power amps on the Denon are turned off. An external amp would be used to power the L + R channels, and that amp would also be used for any stereo inputs. Is this possible, and if so, how might I handle room EQ for the different sources?

Thanks!

 

[Kal Rubinson]

You can handle the sub by buying one with line level L and R inputs. These are independent and can be used for the two different sources. The complication is that the sub feeds would not be affected by the volume controls in the Pre90.

EQ, of course, would have to be independent in the two source devices unless you added a more complex active device downstream.

 

[Epos7]

The complication is that the sub feeds would not be affected by the volume controls in the Pre90.

Thanks, good to know re: line level inputs. That said, it wouldn't be very useful without volume control as you say. It seems like the only way to share the subs may be to use the AVR as a pre for everything?

 

[Epos7]

If I were to connect the subwoofer to the Pre90 outputs, wouldn't I then be able to control the subwoofer volume with the Pre90?

 

[Chrispy]

Why not just use the 3700 instead of adding in complexity with additional boxes doing the same thing?

 

[DVDdoug]

Normally everything runs through the AVR, which takes care of the switching. From what I found the Denon has 5 analog inputs.

 

[Kal Rubinson]

If I were to connect the subwoofer to the Pre90 outputs, wouldn't I then be able to control the subwoofer volume with the Pre90?

Hmm. Feed the L/R from Denon or the DAC to the Pre90, OK.
If you use the sub for HP/LP from the Pre90 output, that works but that would conflict with using the mains and the sub(s) with the Denon.

 

[Epos7]

I've been chatting with Rythmik as I'm interested in getting a couple of their subs, and their recommendation is to use a preamp with home theater bypass such as the Parasound P6. I think that probably makes the most sense, although the Parasound is a fair bit pricier than the Topping. The P6 in particular has some fairly attractive features like a decent looking phono stage and DAC. Rythmik also suggested a miniDSP 2x4 HD on the subwoofer outs of the P6. That sounds like a pretty ideal configuration to me.

The P6 lists two SNR numbers through its digital input:

• 108 dB (shorted, IHF A-weighted)
• 88 dB (shorted, unweighted)

Which of these numbers should I use for comparison to reviews on this site?