Well I too, in the process of return the 20-30CS to get the CS+ w/s1000 (single sub). If the single CS really does rock, I think a CS+ even does a better job. Just got the 20-39CS a few days ago and have chance to hear it for the first time. Although have no SPL meter, but I can tell that output level is more than match with my old and fried FSR-15 (I didnt think I give the Velo proper calibration then). I used the FSR-15 plate amp to drive the CS. It did a good job until the thermal protection kicks in. This bother me though. For this reason and others as well that prompt me to go to the Plus. BTW, this is my first time joinning the forum. Tam N.