Test Bench: Mirage UNI-Theater Speaker System
In the lab
Frequency response (at 2 meters) front left/right/center/surround: 150 Hz to 10.3 kHz ±7.3 dB subwoofer: 29 to 106 Hz ±2.5 dB Sensitivity (SPL at 1 meter with 2.8 volts of pink-noise input) front left/right/center/surround: 88 dB Impedance (minimum/nominal) front left/right/center/surround: 4.0/5 ohms Bass limits (lowest frequency and maximum SPL with limit of 10% distortion at 2 meters in a large room) front left/right/center/surround: 62 Hz at 67 dB subwoofer : 20 Hz at 83 dB SPL 103 dB average SPL from 25 to 62 Hz 106 dB maximum SPL at 50 Hz bandwidth uniformity 97%
I measured the UNI-Theater at a full 2 meters, which emulates a typical listening distance, allows large speakers to fully integrate acoustically and, unlike near-field measurements, fully includes front-panel reflections, grille effects, and cabinet diffraction. It was mounted on a 6-foot stand, which gives anechoic results to approximately 200 Hz.
Though we typically provide separate frequency response traces for the main left/right, center, and surround positions with their output averaged over an appropriate listening angle for each position (30º, 45º, and 60º respectively), the UNI-Theater has essentially omnidirectional response. So a single average trace represents the sound of this speaker at any listening position and channel assignment: Every measured trace produced results that were virtually identical in shape and smoothness except for small variations. That basic shape is downward-sloping as frequency increases, with a fair degree of roughness across the entire bandwidth. The Wall boundary-compensation switch reduces output below 400 Hz by an ultimate 5 dB.
I measured the Omni S10 subwoofer's bass limits with it set to maximum bandwidth and placed in the optimal corner of a 7,500-cubic-foot room. In a smaller room users can expect 2 to 3 Hz deeper extension and as much as 3 dB greater sound-pressure level (SPL.)
The Omni S10 has excellent extension and bandwidth uniformity, meaning that it will produce output down to 20 Hz with less than 10% distortion and relatively uniform SPL across its useful operating range. Dynamic capability is only about average, however, with a maximum output of 106 dB at 50 Hz dropping off to 83 dB by 20 Hz.
The crossover control has virtually no effect over the first half of its rotation. Below that, reducing crossover frequency on the knob simply sharpens the crossover slope by 3 dB/octave per dial marking. Fortunately there is no level/crossover-setting interaction, so output level should remain fairly constant regardless of how the crossover knob is adjusted.