I thought I would start another thread for this. First, I exchanged my rear woofers to improve the sound of the JBL system, but it sounded the same. I didn't want to put a big subwoofer in the back but, I wanted a little more low end like my previous standard stereo in my Altima. Here are the results of my little experiment. I am sure a lot of owners will appreciate the results. I know I am happy. After wasting $100 bucks on replacement speakers with no improvement, I learned that the stock speakers were not the problem but that the amplifier limited the output in the rear. Even if you fade all the way to the rear the sound is still very low. I think it has something to do with the nav system. So, I decided to try to increase the rear output. I bought a cheap $20 12-band equalizer/booster patched into the power of the JBL amp and fed the rear speakers from the JBL amp through the equalizer/booster. Results. The sound quality is greatly improved with more control. I think this could be done if we had more equalizations setting and a bass boost on the sound screen. I think they limit the bass and volume so the doors don't rattle. I have not finished the installation because I didn't have time, but I am sure others can take these results and improve upon them. Conclusion: Just add an amp to power the rear speakers.
