Coolback Sub

** Discontinued **

Active Subwoofer Amplifier with Digital Crossover

 CoolbackSub.pdf Manual

Coolback Sub is a sophisticated, luxurious and powerful subwoofer "plate amplifier" intended to be build into the back of the loudspeaker. The electronics consists of a digital crossover DCN22 and a class H power amplifier module HPA2K and a dedicated power supply for the digital crossover and the power amplifier. The power supply PSU8AGS features individual rails; one for the digital circuitry; another for analogue supply of the the converters and yet a third for the positive and negative supply for the op-amps. The power supply also features an Automatic sense turn ON / OFF circuit and of course a soft start to prevent house fuse drop out. The toroidal transformer is a 600VA low noise type. All electronics are assembled on a 200mm x 40mm German made aluminium heat sink profile with a height of 650mm. The high quality aluminium heat sink is CNC machined in Denmark. The maximum flange can be 17mm.

The combination of low thermal resistance heat sink and low idle power consumption amplifier module makes the Coolback Sub run very cool.

The only visible on the outside are the connectors (Balanced Input - Neutrik XLR, PC Communication - Neutrik USB and IEC mains Power inlet), Operation Switch (ON-OFF-AUTO) and LED Indicators (ON-StandBy). The Coolback Sub is ideal for an ambitious large high power subwoofer with impedances as low as 2Ω.

The Coolback Sub can be programmed by XOverWizard II standard or XOverWizard II advanced software. The software makes the Coolback Sub a precision tool for the ambitious DIY person and optimal loudspeaker setups can be achieved.






  • DCN22 * 24bit 96kHz Digital Crossover Module
  • HPA2K * 650W (8Ω) / 1200W (4Ω) Power Amplifier Module (bass & sub) - min. load 2Ω
  • PSU8AGS * System Power Supply - 8 Panasonic or Nichicon Capacitors
  • Silent Design Toroidal Transformer 600VA
  • Distortion : <0.08%
  • Frequency response : 5-20kHz (-3dB)
  • Signal/Noise Ratio : >110dB
  • Thermal protection above 80°Celcius
  • Weight: app. 14kg
  • Cut-out dimensions: 540mm (height) x 160mm (width) - Internal Depth 100mm
  • Overall dimensions: 650mm (height) x 200mm (width) x 140mm (depth) © Ground Sound * Products of Denmark