(by poster @mijostyn)
This. Implemented with DSP tools on the fly, at the listening position and a full range of parameters, proper integration of a pair of preferable stereo-coupled and symmetrically (to the mains) placed subs certainly becomes easier and a more likely actuality. I prefer crossing over to the mains in the 80-100Hz range (or higher if dictated by the mains and subs upper range performance permitted), as this also makes the positive effect of high-passing the mains more pronounced while generally, to my ears, making for a better integration between the mains and subs. Seamless integration is more than smooth frequency response for sure, and I couldn't imagine listening without subs implemented as lined out above, be that for both music and movies.
... It has to sound like I am listening to one speaker. As I evaluate lower down I go from listening to feeling. Do I feel that kick drum the way I do at the club. Are those low synthesizer notes shaking me the way they should. Does the room move under low organ pedal. Hearing is one thing feeling is another. Part of the thrill of live music are the visceral sensations you get.
These sensations are missing or greatly attenuated in most home systems. I started playing around with subwoofers in 1978 for this very reason. I wanted to feel as if I were at a live performance. Again, I can now move a subwoofer 15 feet just by delaying it 15 msec. I can change crossover points and slopes on the fly at one Hz increments 2nd to 10th order. You can hear these changes immediately. ...
This. Implemented with DSP tools on the fly, at the listening position and a full range of parameters, proper integration of a pair of preferable stereo-coupled and symmetrically (to the mains) placed subs certainly becomes easier and a more likely actuality. I prefer crossing over to the mains in the 80-100Hz range (or higher if dictated by the mains and subs upper range performance permitted), as this also makes the positive effect of high-passing the mains more pronounced while generally, to my ears, making for a better integration between the mains and subs. Seamless integration is more than smooth frequency response for sure, and I couldn't imagine listening without subs implemented as lined out above, be that for both music and movies.