yes, you retain all you oem features. the only thing about the volume is that jl provides a master volume knob that they suggest you use. the reason being, is that the cleansweep calibrates at a certain volume level. due to the oem eq being different at different volume levels, and since the processor can not auto recalibrate, (no processor can) the sound may be slightly off when using the oem volume knob. however, once you get to the volume level that you originally calibrated at, you will have optimum sound. to be honest, most people wont hear the difference unless i show them.