Gamma then doubles up on 15.5cm midranges and lateral 23.5cm woofers. The summed surface area of the twinned mids facilitates a low 115Hz high-pass. That prevents the woofers from becoming acoustically directional. Dual woofers obviously promise solid bass. Over standard metal cones, these also promise reduced breakup modes thus lower distortion by using composite aluminium-titanium-magnesium aka Altima membranes. Quadral have worked with/on this special alloy for already two decades.
Their four dynamic drivers are powered by 2 x 150-watt class D amps whose advantages of high efficiency, low heat and general speed here can really shine. Pulse-width-modulated or PWM gain circuits generate steeper impulse edges than slower linear amplifier topologies. Quadral's German partners Meracus supply these class D solutions as they also do for the Aurum integrated and mono amplifiers.
Gamma's electronic brain runs on two DSP hemispheres, one for the crossover, the other for the full version of Dirac's Live room correction algorithms. Fundamentally I don't consider Gamma's sealed box (no bass-reflex ports) and narrower vertical dispersion of its MTM array as particularly room sensitive. But armed with a microphone, the careful listener can generate a room profile and save up to four compensation curves to minimize in particular peaks in the frequency response. To be sure, that merely treats symptoms not their cause. My listening comments to follow are based on familiarity with my acoustically optimized listening room and Gamma's uncorrected response. Aurum's app can defeat any Dirac DSP compensation with a finger tap so comparisons are easy to do.
The analog XLR and RCA inputs obviously add A/D conversion. Given likely buyer aversion to avoidable compromises in this price class, I suspect that the Aurum Gamma will be of particular interest to demanding listeners with predominantly digital music libraries; and those who appreciate its built-in streaming capabilities. Connection to the local area network is via RJ45 Ethernet or WLAN so Tidal, Internet radio and local NAS all become possible music providers. The master speaker also has Toslink and USB-A, the former to upgrade flat-sounding flat-screen televisions, the latter to connect USB sticks or hard disks. Music data on USB sticks rely on FAT32 formatting—exFAT didn't work for me—then operated instantly, albeit with just basic folder trees and zero cover art. USB-A streaming worked exclusively with Quadral's Aurum App which at first glance didn't blow me away with advanced graphic design but worked reliably. Only album to library-view switches automatically skipped back to 'A' to slow down my overall navigation. My primary listening sessions used BubbleUPnP and my local Minim server which obviously supported full album art and multiple library views.
