Hi John, It is a standalone DSP unit that can be bought either in with a
speaker or on its own. Only an on-off switch with nothing to adjust. I
bought one and works quite well. I have the TS570DG which has DSP but
certainly not as good of system as very expensive rigs. I find that in some
situations the clearspeach works better and in others about the same. I am
glad I have the builtin DSP in rig as well and both have come in handy at
one time or another. Think it costs around $140 but to me is worth it.