This is as good a time as any to delve into what to look for at Data Bass.
The vast majority of people go right to the CEA-2010 Burst test, which is, to anyone who has experience with subwoofers, a mistake. For example, the 20 Hz burst has a duration of 0.325 second. What a subwoofer can to for less the 1/3rd of a second is not relevant to its performance.
The real information at Data Bass can be found in the long term sine wave tests. There is a page here that shows these results:
http://www.data-bass.com/data?page=systems&type=2For a subwoofer in the price range, look at the average for 20-80 Hz. That is the priority for a relatively affordable subwoofer, the two octaves from 20 to 80 Hz.
In terms of real world performance, almost every, if not EVERY, subwoofer that is ported will have audible chuffing at high volumes. It's just a matter of physics. This chuffing will not turn up in any measurement test, but it sure is an ugly sound.
One aspect of the EP-600 is, due to the huge port area, port chuffing will not occur. In the real world, even though it loses a couple of dB at 20 Hz to some others, it will sound better at higher volume levels. To put it simply, unlike other subwoofers in its price range, you just cannot get an EP-600 to make a bad sound.
