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Hertz HMP 4D 600 Watt 4 Channel Amplifier


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Fitment Fitment: This amplifier easily fits in any Harley Davidson touring bike fairing of all years. We also make Bond-In amplifier mounting racks that are specific to this amplifier for mounting inside a saddlebag or a tour pack.

Hertz Performance in a Small Footprint

Thanks to the ultra-compact cast-aluminium chassis (IP64 rated), the HMP 4D amplifier is nature-proof, being the ideal choice for motorcycle installations. It features an incredible power/size ratio and an easy setup thanks to the integrated crossover filter. The Front End section features a complete and bypassable crossover system, providing full system design flexibility with or without external processors, offering the user endless connection possibilities with any source. Inputs feature a special balanced circuitry, ensuring high rejection against electromagnetic interferences, for noise-free results.

TestedWe put this amplifier through a long series of tests in a couple of '18 Harley Street Glides. we found that this amplifier has a particularly low noise floor and a power supply section that far exceeds just about any other micro sized amplifier that we have ever tested. This amplifier is ideal for either speakers with moderate power requirements in 4 channel mode or fro high power speakers with the amplifier in bridged 2 channel mode. For example: JL Audio C1 and C2 series, Rockford Fosgate, and Diamond Audio speakers are a perfect match in 4 channel mode. Or high power speakers like Hertz SV165/St25, MPX165.3, MPX690.3, HMX 8 S, or Diamond Audio HXM8 speakers with this amplifier in bridged 2 channel mode. This makes this amplifier a very attractive choice for a lot of different systems.



Channel mode 4 - 2
Output Power (RMS) 
@ 14.4 VDC
60 W x 4 (4 Ω)
75 W x 4 (2 Ω)
150 W x 2 (4 Ω)

65-85-115 Hz @ 12 dB/Oct.
65-85-115 Hz @ 12 dB/Oct.

Distortion - THD 
(100Hz @ 4Ω)
0.2 %
S/N Ratio 
(A weighted @ 1V)
95 dB
Damping factor 
(100Hz @ 4Ω)
Size W x D x H 
mm (in.)
223 x 100,5 x 43,6 / 8.77 x 3.95 x 1.71


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