@txavgut --
If used 50/50 for movies and music a 20Hz hard deck might be a very appropriate compromise. A lower tune affects bass presentation, and while depth-wise it will reveal infrasonic information found on the source material from select Blu-ray and 4K UHD titles, it also has impact on the central to upper bass character and therefor potentially, depending on the chosen cross-over frequency, the integration with the main speakers.
I like crossing over to the mains fairly high (~85Hz), while not least high-passing the main speakers at the same frequency to relieve them from the lower to central bass, which then cleans up their upper bass to lower midrange and adds further headroom. Similarly, if one would, I prefer not to run the midrange/HF horn + compression driver down to their lowest (professionally) recommended cross-over frequency, but just enough above it (with high-order slopes) to clean up the sound bit and aid energy-coherency (that’s the term again - energy coherency: in combination with phase and timing behavior it’s vital for music reproduction to create a smooth sphere or "radiation bubble" of sound in front of you).
Honest 20-ish Hz extension at close to war volume, still effortlessly reproduced, is something that won’t be easily forgotten, and makes sub 20Hz extension that’s any less capably reproduced (i.e.: that takes loads of displacement area, btw.) seem kind of blah and not worth it. Just my $0.02..
The system will be used 50/50 for movies and music. [...] the subs (LFC-15sm) don’t seem especially impressive, claiming response only down to 20Hz. But I realize specs aren’t everything.
If used 50/50 for movies and music a 20Hz hard deck might be a very appropriate compromise. A lower tune affects bass presentation, and while depth-wise it will reveal infrasonic information found on the source material from select Blu-ray and 4K UHD titles, it also has impact on the central to upper bass character and therefor potentially, depending on the chosen cross-over frequency, the integration with the main speakers.
I like crossing over to the mains fairly high (~85Hz), while not least high-passing the main speakers at the same frequency to relieve them from the lower to central bass, which then cleans up their upper bass to lower midrange and adds further headroom. Similarly, if one would, I prefer not to run the midrange/HF horn + compression driver down to their lowest (professionally) recommended cross-over frequency, but just enough above it (with high-order slopes) to clean up the sound bit and aid energy-coherency (that’s the term again - energy coherency: in combination with phase and timing behavior it’s vital for music reproduction to create a smooth sphere or "radiation bubble" of sound in front of you).
Honest 20-ish Hz extension at close to war volume, still effortlessly reproduced, is something that won’t be easily forgotten, and makes sub 20Hz extension that’s any less capably reproduced (i.e.: that takes loads of displacement area, btw.) seem kind of blah and not worth it. Just my $0.02..