I wanted to add... can you just install a DSP with no other upgrades to change the sound of the oem speakers?
Or what if you included some decent sounding speakers as well with a DSP?
I'm simply trying to get some perspective from a cost prohibitive factor, given not everyone may have the budget for additional amps, with profession installation of new speaker wiring & power cables.
If you add a DSP, you have to add an amplifier (unless you go with the Helix PSIX DSP, a great unit, but you'll still likely want a sub amp). And you can get good speakers so cheap there's no reason not to upgrade them.