I recently swapped the factory speakers in my 2007 Chevy Silverado. My front factory speakers went out, so I had to upgrade them and decided to swap the rear out, too. I kept the factory radio and it's a regular cab truck, so I know the sound is not going to be awesome anyway but hoped to improve the quality a little. The front door speakers sounded awesome when I replaced them. Next I replaced the speakers behind the seats, in the rear "B" post, with Pioneer 4x6 speakers. I got the highest quality Pioneer 4x6s that Crutchfield sold. They are rated at 200 watt max, and freq. response of 41-29. 88bd sensitivity and 4 ohms impedance. The mids and lows are average but they are awful on bass. The speakers just set and vibrate with terrible sound. The bass through them sounds like a baby trying to spit out bad carrots. I know with my factory head unit I am not going to get awesome sound, and don't want something that can be heard 5 miles away, but these rear 4x6 Pioneers sound worse than the factory paper speakers did. Crutchfield told me to place bass blockers in line to cut off the bass to them and see if that helps. I know nothing about car audio installs, and have no idea which bass blockers I would need to install anyway. All the numbers I just listed above mean nothing to me, I'm clueless to them. I was hoping someone on here could give me some advice. Any help you guys could give me would be greatly appreciated.