I have a pioneer DEH-P6900UB head unit with the usb input. I had it in a different car and connected a sandisk 8 gb flash drive to it with no problems. In the malibu I have now, I have to turn the input level almost all the way up so that I do not have to turn the volume knob almost all the way up just to get a normal sound amount. Is there a reason for this?

what else do you have for a system .... how is different than the other car ?

The first car was a 02 Pontiac Grand Prix. When I put the hu in it, I had replaced the factory 6X9's in the rear deck with sony xpld 4-ways. The Grand Prix had 6X9's in the rear, 5 1/4's in the front doors, and factory tweeters. The malibu still has stock 6X9's in the rear deck and it has stock 4X6's in the front door. However, I did notice the stock speakers are 8-ohm. I think the hu put out at 4 ohms.

Oh yea. BTW I only live a few miles west of you in Athens. It's nice to see other folks from north Alabama here.

odd that anything in the car would be 8 ohms. Running 8 ohms speakers will halve the effective power of an amp rated at 4 ohms. I think the new speakers are just less efficient than the last ones.

The best solution to the problem and to add sound quality would be to replace the stock speakers with aftermarket. Would you agree?

if those speakers are less efficient, it will be tye only way

When i pulled the stock speakers out of my cadillac I had 8 ohm stock 6x9s, its not that rare. As for the low input level, I'm sorry I can't help. Just wanted to comment on Pauls comment