hd Qi5002

DSP system amplifier

  • High-End hd MultiDSP with 4In/4Out
  • 2x 500 W Class D amplifier with PFC
  • 2x DSP-AUX XLR output
  • FIR & IIR filter
  • maximum operational safety and unlimited flexibility
  • multistage limiter architecture
The hd Qi-Series is a modular, flexible hardware and software solution for operating Harmonic Design loudspeaker systems. The 2U, 19″ rack hardware includes four balanced inputs and up to four power outputs, which can be processed thanks to a high-performance DSP with IIR and FIR filter technology. The associated user software hd LevelZ allows clear access to all parameters through a Windows-based computer or directly on the amplifier via the 3.2 “LCD display with navigation buttons.

2- or 4-channel Class-D amplifiers provide 500W for each power output. They are designed to meet the highest audio quality and reliability requirements in fixed installation projects and mobile applications. Due to the extreme efficiency, the heat generation is absolutely minimized compared to conventional analogue amplifiers. The power amp needs less cooling and works permanently in the safe area. An intelligent temperature management system ensures the lowest possible noise emission and activates the fans only when required by the operating situation. Always-reliable operation is ensured by up to two independent switched-mode power supplies with Power Factor Correction (PFC) that deliver full performance at all times, even in adverse network conditions, such as undervoltage or overvoltage, thanks to their universal operating range of 85V to 265V and are therefore far superior to conventional power supplies.

For applications that require more amplifier power in the 2-channel version hd Qi5002 two XLR DSP outputs are used to operate a conventional power amplifier with more power. In a system with two tops and two subwoofers, the top speakers would operate over the hd Qi5002 and the subwoofers through the external power amplifier – but with hd MultiDSP processing to ensure optimal sound.

The integrated digital system controller hd MultiDSP has a comprehensive equalizer section consisting of 16 IIR filters in double precision with freely selectable frequency, quality, gain and slope and a FIR filter per input/output with a multi-stage limiter architecture each channel exists. This allows the system engineer to create a user-specific FIR for the installation, using the same approach as conventional multiband equalizers, but without the inherent phase shifts.

Model hd Qi5002
Output circuit Class-D PWM-Modulation
Power rating (RMS @ 1% THD) 2x 250 W @ 8 Ohms
2x 500 W @ 4 Ohms
2x 725 W @ 2.7 Ohms
Operating voltage universal working range from 85 V –
265 V AC 50/60 Hz
Power supply self-regulating switching mode power supply, PFC
Standby 0,3 W
protection circuit switch-on delay, input limiter,
short circuit protection, DC protection
on the output, over-/undervoltage protection,
temperature monitoring
Controls power on/off
5x navigation buttons
Display 3.2″ LCD display with 4 lines of 20 characters each
LED-VU meter each channel
Connection USB B jack
4x input XLR (balanced)
4x link XLR (balanced)
1x power socket
2x output Speakon NL4
2x DSP XLR output (balanced)
Dimensions (W x H x D) 2U x 19“ x 300 mm
Weight 7 kg
Enclosure 2 mm steel sheet
powder coating black
silkscreen white


  • fixed installations
  • public buildings, conference and media technology