Speakers arent real loud at full volume

Hey guys i have a Sony cdx -7700, and i have them ran with Infinty Kappas 6x9 2 ways and 3 1/2, the problem is i can turn the volume like half way up and i cn bairly hear the music i have to turn it up to like 3/4 to full just to hear it nicely, what do you think the problem is. Ernie

You need an amplifier. Those little head units, no matter what they say, only put out ~12w per channel, and poorly at that. It is simply a space issue. There just isn't enough room for large amplifiers in a single DIN with all the other electronics. Buy a small 4-channel amplifier and you'll never have a volume problem again. Unless you think you're really going to get into car audio, just get a low powered amplifier from a quality brand. Something like this would be sufficient: Alpine 40w x 4New Project: 2003 Pathfinder