The EA-7 speakers don't have the same "ooomph" that the SX has, but it sounds nice at lower volumes. I'd describe it as "boxy". There's not as much area for bass reflex in that teeny package. Not a downer for most, but I like the SX to stand alone for many of it's intended uses. I hooked up the Fishman sub to it today, and MAN - what a great combo.
https://www.sweetwater.com/store/detail/SASub--fishman-sa-sub-300w-subwoofer-for-the-sa330xHIGHLY recommended.
So....Let me understand this.. By adding the 300 watt sub woofer, you loved the sound

Did you get enough ooomph?
Dave everything I read says bring out the lows of your guitar etc.. Very vague specs. What is the frequency response specs.. I can't find anywhere.
It says 109db (typical low rate).
Is it really designed to compliment a guitar then a true sub?