Denon 3806 Audyssey "Flat"?

I was playing around with the different Audyssey functions and it's unclear to me what the "Flat" correction curve does. There is a "no eq" function available so I figure it's not that. Can someone help me get my head around this?

http://usa.denon.com/AVR3806DFU.pdf

"The AVR-3806’s Room EQ function offers three
correction curves: “Audyssey”, “Front” and
“Flat”. These can be selected after performing
the auto setup procedure. Details of the
different correction curves are described below.
• Audyssey:
This adjusts the frequency response of all
speakers to correct the effects of room
acoustics.
• Front:
This adjusts the characteristics of each
speaker to the characteristics of the front
speakers.
• Flat:
This the frequency response of all speakers flat.
This is suitable for multi-channel music
reproduction, from discrete music sources
such as Dolby Digital 5.1, DTS, DVD-Audio
and Super Audio CD."

Thanks, Nick

"Flat" makes adjustments to the eq to balance out the room response/speaker response to make the overall response as flat (smooth out the peaks or dips in frequency response) as possible using the audyssey eq.
Brad

Nick,
If you have the EQ set to Audyssey, the EQ will add a bit of high frequency roll-off in addition to the room compensation. The HF rolloff is for taking the brightness out of DVD's that have not been equalized for the difference between movie theaters and home theaters. The rolloff is supposed to be similar to the effects you would get from Denon's "Cinema EQ" setting.

With the EQ set to Flat, there is no HF rolloff, just room compensation. The only difference between the Audyssey setting and the Flat setting is in the high frequencies; mid-range, bass, etc. should be the same for either setting. The recommended setting for listening to music is Flat.

Ah-ha, thanks for the explanation Ed. That fills in my information gap. It also explains why I have preferred movies better with "no eq" as contrasted with "regular" Audyssey because I had noticed what I thought of as a "clearer" sound with "no eq".

Nick