• Product type: Compact 4-channel Class D amplifier
  
• Series: Hydrogen Series
  
• Model: GZHA MINI FOUR
  
• Channels: 4
  
• Output power @ 4Ω: 4 × 80W RMS
  
• Output power @ 2Ω: 4 × 130W RMS
  
• Bridged output @ 4Ω: 2 × 260W RMS
  
• Maximum output power: 640W, CEA-2006A / 10% THD+N
  
• Frequency response: 5Hz–38kHz
  
• Crossover functions: HPF / LPF / BPF
  
• Bass boost: No
  
• Phase adjustment: No
  
• High-level input: Yes
  
• Auto turn-on: Yes
  
• Remote support: Optional GZTA wired bass remote
  
• Input sensitivity: 300mV–6V
  
• Internal fusing: 1 × 40A
  
• Stereo stability: 2Ω
  
• Bridged stability: 4Ω
  
• Dimensions: 135 × 210 × 52mm

• Delivers 4 × 130W RMS at 2 ohms for strong multi-speaker amplification
  
• Bridges to 2 × 260W RMS at 4 ohms for higher-power two-channel applications
  
• Compact 210mm-long chassis suits tighter amplifier locations
  
• HPF, LPF and BPF controls support front-stage, midbass and multi-way system layouts
  
• High-level input with auto turn-on makes factory-source integration more straightforward

• Front-and-rear speaker amplification
  
• Active two-way front stages using four amplifier channels
  
• Two-channel systems requiring 2 × 260W RMS bridged output
  
• OEM audio upgrades using high-level input
  
• Compact builds needing useful power without a large amplifier footprint

We were impressed its four-channel-to-bridged flexibility. It can run four speakers at useful power or become a strong two-channel amplifier, giving us the more to adapt the amplifier around the system rather than the other way around.