There will be a dramatic difference between the 340's and the SVS speakers. Just the efficiency difference is huge.
Going from the SVS fronts to the 340's would have the same affect as upgrading your amp from 100 watts to 400 watts. (To those that will freak out about that statement, do the math between power requirements of speakers when the efficiency difference is 6 Db.)
Add in the fact that the 340's have now been upgraded to the SE version and the comparison just gets downright unfair. Obviously, there is a big price difference so there should be a big sound difference. Also, as you go down the Ascend line the differences won't be as dramatic but if you are looking at 340's instead of the SVS speakers there should be a pretty dramatic difference.
Darren
There's no place like 127.0.0.1