I apologize ahead of time if this is covered and I haven’t found it. Of course if it has, please point me in that direction. Also when it comes to audio and sound I know virtually nothing short of how to adjust the volume. What I want to do is update the factory speakers and maybe add a little bass….maybe. Is something like this achievable with the factory CDM radio unit? I’m also going to do the Bluetooth upgrade to the CDM. Using an aftermarket deck is not an option for me, personally I don’t like they way they look at all, and the retro sound products-well, I’ll keep my opinions to myself, but not an option either. I know these old school systems are severely out dated but looks are everything. 1991 standard cab K1500.