I had the volume control at 50% and could barely hear it and I found that even at full volume, it was still relatively benign. With my Energy sub, I had it set at about 55% of max volume and in my pre/pro I dialed it down – 5 db (to get 80db on my SPL meter)otherwise, it was to much bass. With the EP500 on full volume, I did not perceive it as loud as the Energy at 55%. But after running an SPL check, it was clocking in at 80db, just did not sound like it was. So, I changed my pre / pro setting from – 5db to 0db and then set the ep500 to 70% of volume. That gave me the “umph” was I looking for.
There could be a multitude of reasons for this observation. Sub box tuning frequency, interaction of the sub with the mains, room response, etc.
At the end of the day, to have a flat frequency response is the goal. The only way to truly judge if there are frequency response dips and peaks would be to do a plot. Play around with Room Eq Wizard. I have found it to have a good balance between features and ease of use.
Last but not the least, have fun and enjoy your new EP-500.
