It looks like you would get a little more volume (500 vs 300 watt), a little lower range, but you would loose the upper bass range of 100-150 hz, which isn't a problem if you use 80-100 as your crossover point. It looks like all of the sub-woofers above the EP350 has a lower top end. This is probably just a result of acquiring a better bottom end.

https://docs.google.com/spreadsheet/ccc?...amp;usp=sharing