Maybe I’m missing something, but is the loop on your Peachtree before or after the volume control?
If before, then whatever component is connected in the loop won’t have its volume controlled by the Peachtree’s main volume control. If this is the case, then you’d have to independently re-adjust the volume of your subwoofer every time you adjusted the main volume control knob, and that’s just not practical.
But maybe I’m missing something... ?
Please read the Vandersteen 2WQ manual:
You can insert the capacitor to the loop and connect a subwoofer to preout or speaker output as long as the subwoofer has a contour opposite of the low frequency 6dB/octave roll off induced by the capacitor.
If I understand correctly, the Vandersteen hookup puts a 6dB highpass filter into the loop, and then the sub is AFTER the loop, and receives a speaker-level signal. The sub’s internal lowpass filter is the inverse of that 6 dB highpass filter. Is the right?
If so, that makes sense to me.
Perhaps I misunderstood hammy1750 when he said he "would like to add a subwoofer into the amps loop function to take the load of the 80Hz and below off of the amp and DQ-10s and onto the sub." I interpreted that to mean the sub’s line-level input and line-level highpassed output would be connected to the loop’s output and input respectively, which would have placed them in the signal path before the volume control.
Edit: Looks like we were typing at the same time.
6 dB/oct low pass is too slow for a sub. You will have it running up into the mid range. IMHO 12 dB/oct is the slowest I would use.
Why not just get a sub like a JL Audio with a fully active cross over in it that can be adjusted to suit? If you do not want an active crossover on the DQ 10s just put the right cap on the input of the amp (you have to know the exact input impedance) and passively role the DQ 10s off at 6 dB/oct? If I remember correctly Dalquist's own original cross over the DQ-LP1 had a 12 dB/oct adjustable low pass filter then they gave you a fist full of capacitors to install in your amp. (6 dB/oct high pass)
" Is there a way to set a subwoofer up to stop the nova from amplifying 80Hz and below and still be controlled by the novas volume control."
Yes, by using the Vandersteen subs with the setup procedure imhififan linked to. The filter slopes are shallow at 6 dB per octave, so imo you might want to position the sub along the same wall as the main speakers and in between them.
Unless the Nova has pre-amp outputs and power-amp inputs, the Vandersteen approach is probably your best bet. It's really quite clever, kudos to Richard Vandersteen for coming up with it.
If you get a sub that has high level inputs AND outputs, you could run speaker cables from the peachtree into the “in” on the sub, then go from “out” into your speakers.
Another option is to run your dahlquist’ full range and get a subwoofer with speak-on connections, like Rel or Sumiko. Sumiko subs are 50% off right now at TMR
6 dB/oct low pass is too slow for a sub. You will have it running up into the mid range. IMHO 12 dB/oct is the slowest I would use.For example, if the loop input impedance is 10kohm and a 0.2uF capacitor inserted to the loop to create a 6dB/oct roll-off at 80Hz, what you need is the subwoofer can provide a contour inverse of that 6dB/oct roll-off, above 80Hz, it dosen’t matter if the low pass is 12dB or even 24dB.