Interesting question. I hope someone who knows can offer answers to the following (obviously I'm not that "someone"
)
1. In a processor/receiver, are
full range copies of all channels which are set to "Small" combined together with the LFE channel? Rather than "full range copies" of all channels being combined with the LFE channel, I have assumed that only the info below the crossover point set for each speaker was combined with the LFE channel and sent to the subwoofer.
2. If this summation (full range speaker copies/LFE) is actually low-passed, assuming you're using different crossover points for each speaker (mains at 60Hz, center at 80Hz, surrounds at 100Hz, etc.), which crossover point is used to low-pass the combined signal?
I know little about how the internals of a processor/receiver work, but I would've thought the info from the speakers below the set crossover point (say 80Hz), would be combined with
all the info in the LFE channel, and sent to the subwoofer without the need for any more low-passing, or, if more low-passing was necessary, low-passed at a higher frequency (say 120Hz). LFE does stand for
LOW frequency effects doesn't it?
Regardless, the article goes on to say:
"
Don't panic. This has been going on since day one, and virtually nobody has noticed . . . with good reason......THX looked at an inordinate number of modern 5.1 soundtracks and guess what they found in the LFE channel: not much at all in the region of 80 Hz - 120 Hz, making their original choice of 80Hz rather fortuitous. Dolby Digital's LFE channel has a digital brick wall at 120 Hz, not a roll-off, so content creators almost always roll-off their stuff, usually somewhere around 80 Hz. Therefore, chucking the top band of the LFE is no big deal....."
OK, now I'm
really confused.
