Looking to upgrade my entry-level pioneer DEH-14UB Head Unit IF it will make a worthwhile difference in output or sound level mainly on my sub-stage going with a 4-6v pre-out upper-class pioneer, kenwood or alpine deck. Tell me what do you guys think? I already have the entry-level pioneer wired to a clarion MCD-360 crossover with 5v max output voltage so am I really going to notice a difference in the bass production from the subs or no?? All comments and opinions are appreciated thanks:)