2004 Focus factory Stereo
 

When I try to higher the bass, why won't it go past +7?

+7 is as high as it goes? and moving to the audio section

It's been so long since I had the original radio in the car but I think that was as high as it went. If you want more bass, it's time to start upgrading your system.

agreed, it only goes so high and may cause distortion. time to start upgrading if you want more.

increasing the bass using that feature will only put more wear and tear on the speakers.