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Quantum 731 A

Active subwoofer, bass reflex, downfire

  • Home cinema bass: Subwoofer for the Quantum 750 range
  • Punchy, dynamic bass reproduction for music and film
  • 300 mm long-excursion downfire subwoofer for precise and powerful deep bass
  • High-performance amplifier with a maximum power output of 360 watts
  • Extremely low-resonance, solidly built enclosure with a multiple braced body

Active subwoofer, bass reflex, downfire

The Quantum 731A is the perfect low-bass counterpart to the Quantum 750 series. Besides the extremely low-resonance 45 mm case front on a corpus with multiple stiffening, it offers a clear and modern language of shape that is available in perfect high-gloss or silk-matt varnish finishes. The latest-generation computer-optimised long-throw subwoofer chassis delivers uncompromisingly clean and dynamic basses.

The Quantum 731A is available in a black, white or black-mocha finish. A long-throw subwoofer chassis with a diameter of 300 mm and hardened paper cone, high-strength die-cast basket and ventilated high-performance voice coil is responsible for ideal bass precision. The high-gloss base plate maintains a defined distance to the chassis for optimum level efficiency, the high-performance power amplifier guarantees highest level reserves.

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Technical specifications

  • bass reflex, ‘Down-fire’ construction
  • 300 mm Woofer
Output power (RMS/Max.)
  • 180 / 360 watts
Frequency Response
  • 18 - 200Hz
Crossover Frequencies
  • 40-180 Hz adjustable
  • switchable 0°/180°
Dimensions (WxHxD)
  • 340 x 568 x 475 mm
  • 26.1 kg
Cabinet surface
  • Piano Black/Black satin
  • Piano White/White satin


Amplifier and power supply
  • Active SPL equalization up to 180Hz
  • Clearly arranged control panel made of brushed aluminium with large, integrated heatsink
  • Volume and crossover frequency adjustable
  • Phase switchable 0° - 180°
  • Real-time Limiter for less distortion and to prevent surmodulation of the speaker
  • Separate standby power supply for low power consumption in standby mode
  • Surge protection with LED indicator light
Highly modern design with silk matt lacquer and aluminium applications
  • Subwoofer
Woofer / midrange
  • Ventilated high-performance voice-coils ensure a high degree of operational reliability
  • High-power long-throw woofer
  • Coated and hardened paper cone for deep and

    dynamic reproduction
  • Klippel®-optimized magnetic field
  • Stereo low level inputs
  • Stereo high level inputs
  • LFE input
  • Very solid and elegant construction using MDF panels and elaborated struttings
  • 35 mm base plate in high gloss painting finish
  • ‚Downfire’ construction
  • Airflex ports with extremely wide openings for optimized bass connection
  • Big rubber resonance absorbers
  • 45 mm thick, two-layer front panel in a high-gloss varnish finish
Cabinet surface
  • Piano Black/Black satin
  • Piano White/White satin


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