I'm not sure I agree fully with his stance that running from the power amp is better. Some do like running from the power amp in that they want the signal going to the sub bass to be given the same distortion/compression characteristics as their amp ("maintaining the sound quality"). However, the downside is that more distortion and compression is going to the sub so it technically won't be a clean reproduction of the bass signal from the source material. A good example would be the majority of tube amps. A good majority of tube amps out there do not handle deeper bass very well as they go through things like transformer saturation. As a result the signal in the low bass tends to have a good amount of compression and distortion so the sub bass will not sound as full and will sound strained due to that. The other part of the double long interconnects doesn't apply as you are using two separate preamp outs, one balanced and one unbalanced. So you don't have to worry about parallel capacitance. In terms of the length of the unbalanced run to the sub, long unbalanced interconnects don't affect the sub as much as it does your main speakers. With main speakers, most tend to recommend keeping the runs below 20ish feet or so due to capacitance and signal degradation at high freq. However since the sub is reproducing frequencies in the low sub bass, you would have to run hundreds of feet before those frequencies are affected.
If you run to both the high level and low level inputs on the sub, then your LFE might still work, but I feel that it still may cause some odd effects such as freq overlap as it would be receiving signal from two separate sources. You also need to engage the crossover on the sub for both 2ch and HT. If you want to connect it that way, then the best way is to get an RCA switcher to disconnect the signal from the LFE when you're playing 2 ch material, and get a speaker switcher to disconnect the speakers from the sub when you're playing HT.
Last edited by Kevin_Hsu : February 25th, 2019 at 3:55 PM.