I've been following the thread on you EP350 and you have been receiving solid advice. Positioning of your subwoofer is of importance and I would suggest that you pull away the tables from in front of the subwoofer. Since it is firing towards the mains set the phase to 180 to work in sympathy with your mains. If left at 0 you are actually cancelling bass.
As suggested, tweak down the volume on the subwoofer amplifier and add gain via the HT receivers menu system which will activate the sub at lower volumes. I would also recommend that you do utilize a SPL meter and set your system manually trying to achieve a blending of output throughout the speaker system.
After setting the crossover in the receiver bypass the crossover on the subwoofer.
