Hi spoiler,
Don't forget that the EP-500 has three custom EQ settings with full, half, and flat that are designed for use with small, moderate, and large rooms, respectively. The settings half and even more so, the setting full, will actually boost above 30Hz and this may help you in the dip that you see from 25 to 50Hz. One thing that you should be careful when using the SMS-1 is not to boost any frequency or stack frequencies with boost as this will obviously strain the sub. I imposed resctions on myself when using the SMS-1 such that I decided to never boost more than 3dB (max is 6dB) or stack EQs side by side or on top of each other. (You can choose which frequency to adjust and technically you can boost or cut two frequencies that are very close to each other and even overlap so you can boost up to 12dB !). Fixing peaks, of course, is another matter and this is where you can use the SMS-1 to great advantage.
John
