Soft-start remote switch on Line level RCA & high level speaker inputs Short-circuit & thermal protection built in Front channel cross over with optional high pass filter Rear channel cross over with optional low pass filter Independent bass boost onoff for front & rear channels Independent gain control for front & rear channels Bridgeable output to 2 x 200W output The Nikkai 4-channel car amplifier provides even greater options & performance whilst still representing excellent value for your money. The amplifier can be configured as 4-channel full range or 2-channel bridged with user-selectable bass boost & gain settings. In addition to standard low-level RCA inputs the speaker level inputs make it easy to upgrade standard head units without pre-amp outputs.