Originally Posted by
Larry Hoffman 
I posted this in the MCACC forum and got no replies, so I thought I'd post it here as well.
I don't believe this has been asked before and I could use some advice.
I have the 1018 receiver. My sub is an Energy 10.3 that should have output to the low 20's.
I set up MCACC using "Stand.Wave Multi-Point" since our two main listening positions are on either side of the projector, which is on a small table rather than ceiling mounted and takes up the center position. My front speakers are set as "large" and the sub is set as "plus". (speakers, Mirage Frx 9's, have powered subs)
(The center and surrounds are set as "small")
I put on an old Stereophile test cd, just to try the test tones that go from 200hz to 20 hz and see how my sub is performing in the room.
At 31.5hz there is very little sound from the sub when using "Direct" mode, which uses the MCACC settings and no other processing. At 25hz there is virtually no sound energy coming from the sub at all.
If I then change to "Pure Direct" mode, which uses no processing at all, there is a lot more sound from the sub at 31.5hz and definitely energy felt at 25hz.
I can't understand why MCACC would affect the performance of the sub, especially below 40hz.
Also, how does this affect my sub while watching movies in surround? Does it mean that below 40hz I'm missing out?
I haven't done any adjustments other than run MCACC. Generally I'm very pleased with how it improved the sound of movies in my small theater, but now I'm wondering if I should adjust MCACC so the low bass is more audible and how to go about it.