If you have a '16+, make sure to disable the sound processing in Forscan first, that alone helps the most by restoring clipped frequencies, just don't be an idiot afterward and crank your speakers too high. Then you can upgrade your speakers, just use Crutchfield to show you what fits and they also are about as cheap as Amazon while giving you free adapters. Go with the full 6 3/4 size to get the best fit and deepest frequency response. From there you can bass block all 4 channels and add a sub right off the rear speakers using a speaker level input amp.