I have heard the audessey does a poor job with low frequencies.

I have the ep500 and a denon 3808 which also has auddessey EQ.

Audessey set my sub volume to -12db (but checking with an spl meter it was pretty closely calibrated with my other speakers).

However, the distance was way off. You will have to manually adjust the distance of your ep600. You will probably have to experiment, but try setting the distance 6 feet more than it actually is. This will account for the DSP circuitry.

-David