When I bought my headunit from Best-Buy they installed it. I had to carry it back because the front right speaker was not putting out as loud as the left front.My ride is an 1993 F-150 extended cab. The Head installer looked at it and said that this year truck was different and the wiring harness would have to be changed to make the right speaker play like it should. Well it did untill I upgraded all of the speakers,and put a four channel amp in to run the new speakers. All new wiring was put in and the amps and wiring were checked out by a jl dealer to make sure that everything was hooked up correctly. Guess what! the right front speaker is not as loud as the left front?????I'm going to change the crossover's today as a starting point to see if the right crossover is bad. Can anyone suggest what else that I can check ? I'm beginning to think that it could be the headunit??? The system sounds great and nobody could ever tell except the person driving the truck.The headunit is a Alpine 9851-- front speakers are jl comps-rear are jl coaxiels- amp is jl 300/4. The 300/4 was bought new from 12Vikings off of Ebay.I hope that it is not somthing in the amp. I hope that I have provided some of you with enought info to give me some suggestions as to where to look to solve this problem. Thanks.