Rythmik F8

[RythmikAudio]

Thank you. But i was more interested in what the 'audiophiles' do. Obviously, they want to time align their subs, they want to roll off their mains to let the subs do the heavy lifting at the low end, they might want a sharper rolloff than 24db/octave. Or are these concerns not audible?

Please forgive the naïveté of my questions. I have never integrated a sub before and am just trying to learn.

What audiophiles want is for their speakers to disappear. The same thing is for the subwoofer. That is really what it boils down to in the end so that we just enjoy the music and not even realize the presence of speakers/subwoofers.

Crossover has a long history. On one extreme, we have speaker companies like Thiel and Vandesteen advocate 1st order with the largest overlap between drivers (which means drivers have to work wider bandwidth than they normally do). On the other extreme, we have the infinite slope crossover that shapes like a cliff (and therefore claim perfect transition from one driver to another). Both approaches have problem that it creates "lobes" of frequency response and the MLP is not at the peak of the lobe. If you are slightly off that MLP, then you can have large dip or variation in FR. In front speakers, that also degrade sound stage because the image is created by direct wave plus wall reflections. If the wall reflection, which is from the off-axis FR of speakers, is very different from direct wave, the sound stage naturally suffers.

Only after Linkwitz-Riley published their paper on a family of filters with perfect phase alignment at the
crossover point (which includes 12db/oct, 24db/oct, 36db/oct...configuration), engineers begin to realize this "phase alignment" is THE key to all crossover designs. It creates the large "lobe" in the frequency response and the improves the image as well. Ever since them, the Linkwitz-Riley (or simply L-R) becomes the only filter people talk about. In particular, the 24db/oct L-R becomes the most important. All AVRs adopt that configuration in their bass management. It is really the milestone in audio.


As for the question that multiple subwoofer drivers can blur the image, I really don't think it is not bad as long as the drivers are close to each other. David's 340SE is what we call MTM which also has two bass drivers. I never feel the image from those speakers are not as good as any single bass driver speakers I have own or I have heard in the show. The subwoofer reproduces wavelength that is much longer than that from 340SE.

For the amp in HX580, we have all the hooks to add HPF. But HPF has to be in RCA, not XLR. If HPF is highly desirable, we may just add that. This is where we need customer feedback.