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.