These do use such a DSP, but it's not a fixed response. Sonos speakers use the phone amp with a process they call TruePlay to tune their speakers, and TruePlay

These do use such a DSP, but it's not a fixed response. Sonos speakers use the phone amp with a process they call TruePlay to tune their speakers, and TruePlay still works with this after the mod, so you can retune the DSP for pretty much any kind of speaker and room combo.