Products

Web Shop

Download

FAQ

Galleries

Discontinues

Links

Company

Contact

 

Featured Product
H-Amp-XXXV dual channel
High Power Amplifier

On Sale in webshop

Coolback II 300

3-Way Active Amplifier Solution with Digital Crossover

 CoolbackII300.pdf Manual

Coolback II 300 is a sophisticated, luxurious and powerful 3-way active “plate amplifier” intended to be build into the back of the loudspeaker. The electronics consists of a digital crossover DCN23, 3 x class AB power amplifier modules PA1CC & PA3CC, a dedicated power supply for the digital crossover and power amplifiers. The power supply PSU4SA features individual regulated rails; one for the digital circuitry 3,3V; a 5V analogue supply for the converters and 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 dropout. The toroidal transformer is a 350VA low noise type. All electronics are assembled on a 160mm x 40mm German made aluminium heat sink profile with a height of 580mm. The high quality aluminium heat sink is CNC machined in Denmark. The maximum flange can be 20mm.

The combination of low thermal resistance heat sink and low idle power consumption amplifier modules makes the Coolback II 300 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 II 300 is ideal for an ambitious "small" to medium 3-way active DIY loudspeakers.

The Coolback II 300 can be programmed by either the free XOverWizard or the new XOverWizard II standard or XOverWizard II advanced software. The software makes the Coolback II 300 a precision tool for the ambitious DIY person and optimal loudspeaker setups can be achieved.

 

 

 

 

Specifications:
  • DCN23 * 24bit 96kHz Digital Crossover Module (One input channel)
  • PA1CC * 100W (8Ω) / 150W (4Ω) Power Amplifier Module (tweeter) - min. load 4Ω
  • PA3CC * 200W (8Ω) / 350W (4Ω) Power Amplifier Module (mid-range) - min. load 3Ω
  • PA3CC * 200W (8Ω) / 350W (4Ω) Power Amplifier Module (bass) - min. load 3Ω
  • PSU4SA * System Power Supply - 4 Nichicon Gold Tune Capacitors 40.000µF/63V
  • TR300 * Silent Design Toroidal Transformer 2 x40Vac / 350VA (rectified +/-58V dc)
  • Distortion : <0.08%
  • Frequency response : 5-45kHz (-3dB)
  • Signal/Noise Ratio : >108dB
  • Thermal protection above 80°Celcius
  • Weight: app. 9kg
  • Cut-out dimensions: 540mm (height) x 120mm (width) - Internal Depth 100mm
  • Overall dimensions: 580mm (height) x 160mm (width) x 150mm (depth)

 

 


Suitable loudspeaker projects for our active amplifier Coolback II 300:
The listed projects is all 3-way floor standing loudspeakers of high quality, some minor changes to the box design might be required


  Klang + Ton


 

Larger picture Duetta - Published in issue 1/2002
A very popular Klang + Ton reference loudspeaker project developed by the late Heinz Schmitt
Eton ER4 - Air Motion ribbon tweeter * 4Ω * 88dB * 2500Hz-25kHz * 60W
Eton 7-360/37HEX - 7" Hexacone mid-range * 8Ω * 89dB * 40Hz-4kHz * 100W
Eton 11-581/60HEX - 11" Hexacone woofer * 8Ω * 91dB * fs=21Hz * 150W

 

Larger picture Minuetta - Published in issue 5/2005
Cheaper version of the Duetta - smaller mid-range and bass - two choices of tweeter
Eton ER4 - Air Motion ribbon tweeter * 4Ω * 88dB * 2500Hz-25kHz * 60W or
Eton 19SD1 - 19mm silk dome tweeter * 8Ω * 89dB * 2500Hz-30kHz * 80W
Eton 5-880/25HEX - 5" Hexacone mid-range * 8Ω * 87dB * 50Hz-4kHz * 50W
Eton 8-800/37HEX - 8" Hexacone woofer * 8Ω * 89dB * fs=36Hz * 120W

 

 

  Hobby HiFi


 

Larger picture Cumulus - Published in issue 5/2004
High End loudspeaker project developed by Bernd Timmermanns
Thiel/Accuton SC3 - High End Coaxial driver * 4Ω * 90/87dB * 800Hz-25kHz * xxW
Visaton AL200 - 8" aluminium woofer * 8Ω * 88dB * fs=32Hz * 120W

 

Larger picture Faktum - Published in issue 4/2007
Super loudspeaker project developed by Bernd Timmermanns
ScanSpeak R2904/700000 - Ringradiator tweeter * 8Ω * 88dB * 2500Hz-25kHz * 60W or
ScanSpeak 15M 4531 K00 - 15cm mid-range * 8Ω * 89dB * 40Hz-4kHz * 100W
ScanSpeak 22W 8851 T-00 - 22cm woofer * 8Ω * 91dB * fs=21Hz * 150W

 

Larger picture Mezzoforte updated - Published in issue 5/2005
Loudspeaker project developed by Bernd Timmermanns
Visaton SC10N8 - 25mm fabric dome tweeter * 8Ω * 90dB * 1000Hz-20kHz * 100W
Visaton W170S8 - 17cm mid-range * 8Ω * 86dB * fs=36Hz * 50W
Visaton W250S8 - 25cm woofer * 8Ω * 90dB * fs=31Hz * 100W

 

 

  Acoustic Design Magazine


 

Larger picture Blue Note - Published in issue Ausgabe 6
Eton driver loudspeaker project developed by Udo Wohlgemuth
Eton ER4 - Air Motion ribbon tweeter * 4Ω * 88dB * 2500Hz-25kHz * 60W
Eton 5-880/25HEX - 5" Hexacone mid-range * 8Ω * 87dB * 50Hz-4kHz * 50W
Eton 8-472/32HEX - 8" Hexacone woofer * 8Ω * 88dB * fs=24Hz * 90W

 

 

  Dansk Audio Teknik - Danish Shop in Copenhagen


 

Larger picture Amadeus TNT S7
ScanSpeak driver loudspeaker project
R2904/7000 00 - Ringradiator tweeter * 8Ω * 88dB * 2500Hz-25kHz * 60W
ScanSpeak 12M/4631G00 - 12cm sliced paper cone * 8Ω * 87dB * 50Hz-4kHz * 50W
2 x ScanSpeak 18W/8531G00 - 18cm sliced paper cone * 8Ω * 89dB * 40Hz-4kHz * 100W

 

 

active@groundsound.com © Ground Sound * Products of Denmark