Daniel, the off setting means that none of the Audyssey room EQ results are in use(the calibration for speaker levels and delays remains in effect)although the results are still stored. No setting on the separate manual equalizer(not a part of Audyssey EQ) is in use.
The Byp:L/R means that the Audyssey room EQ results aren't in use for the mains, but are applied to the other speakers and sub.
The "Audyssey" setting applies a slight high frequency roll-off(about 2dB per octave above 4KHz, so that the roll-off is about 4dB at 16KHz). This is considered desirable for some movie and other material which has excessive high frequencies for some home room acoustics.
The "Flat" setting, which some misinterpret to mean no EQ, means only that the "Audyssey" high frequency roll-off isn't used, but a measured flat response with the test tones.
The "Manual" setting applies user selected EQ numbers to a small number of specific frequencies(a result Dr. Kyriakakis has termed "crude")and has sometimes been misinterpreted as being a way to "tweak" the Audyssey EQ results. They can't be used together.
