Issues with bass could have to do with a lot of different things.
Ricks comment about running the sub hot seems to be quite common and probably has to do with our reduced sensitivity to sound the lower we get in frequency. [Most] Everyone seems to run their sub hot.
Bass seems to be the most affected part of the spectrum in smaller rooms as well. Small rooms seem to bunch up room modes so that you get pronounced peaks or nulls, so that missing bass could well really be missing without it being the subs fault.
Room modes can also be beneficial. My first mode for room length is at around 24Hz and is probably the reason I am getting extension down to 21Hz with my EP350.
It can also be that whatever sub/speakers you had in the past had a boost at one frequency that you had gotten used to, so when you get a better sub like the EP500 that has a flat frequency response, you feel like you are missing something.
Last, but not least, it can be the position of the sub.
So, there are lots of variables in the equation and it can take a while to sort things out.
At this point there are three things you can do: tweek until you get tired of it and then call it a day, buy an EP800
, measure whats going on in your room to see whats going on.
The only way to know what is really going on in your room is to measure it either manually or with software like REW.
Here is an example of an in room measured response. If you look at the first graph you can see how there are peaks and valleys showing how my room and the position of the sub affects its response. Measuring like this can quickly tell you what is going on with your sub at various positions in your room.
Fixing some of the stuff you find while measuring can be challenging, but once you measure, at least you know what you are dealing with.
