Hi Captain,
DSP in the EP500 will make the sub's overall frequency response smoother--more "linear"--with fewer bumps and dips than, say, the EP350, which doesn't have DSP. The 500's DSP also extends the EP500's deep bass a bit lower than the EP350, and I heard that slightly deeper and more powerful bass in the double-blind tests. However, I recall writing down on the scoring sheet that the 350's deep bass with pipe organ was almost as excellent as the EP500's. Just a hair's-breadth difference.
DSP also prevents the EP500 from being over-driven into potential damage because the DSP chip is programmed to "know" the amplifier's and subwoofer's maximum output capability, so it limits the amp and driver's output just short of where damage might occur.
Regards,
Alan
