Focal Impulse 4.320 4 Channel AmplifierIMPULSE 4. 320 Compact 4 channel digital amplifier With the Impulse 4. 320 amplifier, breathe new life into your car radio. The amplifier of a car radio (standard equipment or purchased subsequently) very quickly admits its limits in terms of power and dynamism. At high sound levels, it quickly goes into saturation and spoils the musical pleasure. To compensate for this lack and allow your speakers to express themselves fully, the Impulse 4. 320 is