I just purchased the Alpine CDA-9815 and noticed it has built in high and low pass filters. Now I'm not going crazy on this. Im just going to get some decent 6x9s and some new in dash speakers that can handle the RMS that the system puts out. I dont think Im even going to get a Sub for it. I have a 93 pontiac grand prix and in the dash i believe are 4x6s. what should i set the high pass filter on the front speakers to and the low pass filter on the rears too??? or should i just leave those off all together since im not getting a sub. the alpine HU puts out 27 watts of RMS per channel and the 4x6s can handle up to 30 and the 6x9s i was looking at can handle up to 50 watts. let me know what you guys think.