maybe you should get a better decent amp to drive ur comp for a better sq. and why you need preamp? as you mentioned, you having a high end clarion hu, most probably you can adjust everything in the hu function. but please check ur hu model 1st if it does come with the function as preamp.

say no to mohawk orange sub too. you can't get SQ with the sub. too boomy and bassy for SQ. unless you send to pro to tune ur system. anyway, just believe your ears.