Add to Cart Compare Quick view Sundown Audio Sundown Audio - SFB-1000.4D Amplifier 4-Channel MSRP: Now: $579.99 Was: Sundown Audio - SFB-1000.4D Amplifier Features High Efficiency Digital Multi-Channel Design 12 dB/Octave – Variable Low Pass Filter 12 SDA-SFB-1000-4D MSRP: Now: $579.99 Was: Add to Cart Compare Quick view