Yes, you've really got to have the convenient independent zone control at your fingertips and on the fly. It could be as simple as the HU fader....IF the HU is on the drivers side, and IF the fader isn't buried in the menu. From there the options include 1) passive RCA line level controllers like the PAC LC-1, 2) active line level controllers with built in line drivers like the JL Audio or Kicker, or 3) active EQ ranging from an inexpensive Clarion up to the Wetsounds WS420 with a couple of dozens options in between.