-=Pause=-
I am a random on the internet, NOT familiar with your system/setup or level of knowledge.
My description of two different setups; one being for active monitors, that do not ‘need’ an amplifier in front of them- not a lot of amplifier buyers are in this camp…
The second was a config, for those with a variable volume part ‘up front’; for me it is my DAC, but ONLY because it has a preamp function where it can vary the voltage/volume output from the rear connectors.
…because it can vary the volume; the signal, after ‘bouncing via the subwoofer’ (certain subwoofers can HF limit the output they send), can feed into the Naim integrated amplifier using the AV BYPASS function (it expects a variable volume feed).
If you use line level outputs , say NOT FROM A PREAMP; meaning the output on the ‘DAC’(not in preamp funciton) would be ‘full level’.
If you fed that via your sub and into your integrated amp:
a)sub would play at full volume
b)amp would play at full volume (if using AV Bypass)
if you were not using the amp in AV Bypass mode, then the sub would play at ‘full volume’ and then you would use the volume pot on the Naim amp to attempt to mix the speakers to match…
Neither of these setups is correct, and, worse, will likely break things.
(will post then edit)
I would recommend place a photo of the rear of your subwoofer up for others to see… to make sure things are ‘set right’.
The traditional way to do this is to feed the speaker cables from your amp into your sub, and then the cables to your speakers run FROM the sub.
This has always been the better sounding method of the two (better than using RCA cables on most subs)
Given my lack of nice speaker cables of suitable length with correct terminations, I do not use the speaker cable method.
It does come down to how the High Frequency cut works on your sub… (the ins and outs available to us)
There IS a couple of ways to do this…
…many paths to the summit.
Have you done this before /familiar with the steps?