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Quantum 670

The ascent into Quantum loudspeaker technology

The ascent into Quantum loudspeaker technology

Based on the visually and technically successful design of the Quantum 650 series, significant improvements have been achieved in regard to the acoustic dynamics, treble reproduction and pulse fidelity. But the loudspeakers in the Quantum 670 series do not only convince with their elaborate technological features. The clean and modern lines and high-quality workmanship turn an acoustic high-tech product into a fine piece of furniture. With the Quantum Center 67 and the Quantum 6725A, this series features two true home-cinema specialists that allow home-cinema systems to be built at a high acoustic level and that visually come from a single mould.

The second-generation drivers have become considerably more dynamic

Newly developed FE Dynamics drivers with very stable aluminium-ceramic cones have been used for the bass/mid-range to produce a very precise and dynamic sound. The non-magnetic loudspeaker baskets manufactured from carbon-fibre-reinforced ABS have been flow-optimised. The voice coils have been designed for high resilience and feature an air-cooling system on the loudspeaker basket. The "harmonic radiation horn" ("HRH") tweeter first introduced in the predecessor series has been further developed in the new Quantum 670 series and now – besides a more finely tuned drive – particularly features a new and flatter design. The new tweeter exhibits a high level of efficiency and also permitted the woofers and mid-range loudspeakers to be recalibrated for a more dynamic overall experience of sound with more of a "live character". The lightweight synthetic-silk dome tweeter possesses a 20% larger cone area than conventional one-inch domes. The completely redesigned level- and phase-optimised crossovers in an acoustic fourth order are also responsible for a completely "rounded sound". High-quality crossover components, including air-core coils and film capacitors, have naturally also been used.

A highly coherent overall package

Large bi-wiring/bi-amping terminals with gold-plated screw connections ensure optimum contact. The bass-reflex coordination and the chassis have been developed with the help of the Klippel laser measuring system using different frequencies and levels. All reflex tubes have been flow-optimised – which can be recognised by their trumpet-like shape – and have been fitted flush and even screw-fastened in the cases for optimum stability and functionality. The elaborate case uses a design that is unusual in this price range. Parasitic standing waves have been reduced thanks to the rounded side panels. Multiple internal reinforcements are also responsible for enhanced stability and freedom from resonance. Solid high-gloss baffles measuring up to 25 mm in thickness guarantee optimum operating conditions for the loudspeaker chassis. Furthermore, the floor-standing loudspeakers also come with a sturdy base plate to ensure separation from the floor. All of the loudspeakers feature height-adjustable rubber feet; the floor-standing loudspeakers also come with metal spikes.

Technical specifications


Features Speakers
  • Airflex Port
  • APOC
  • CVS – Coil Ventilation System
  • Fmax tweeter
  • Ceramic Alu Cone
  • FE Driver Dynamics
  • ABS Basket