Test Bench: PSB Synchrony Home Theater Speaker System
In the Lab
Frequency response (at 2 meters) front left/right 37 Hz to 18.6 kHz ±4.5 dB center 79 Hz to 19.5 kHz ±4.2 dB surround 97 Hz to 18 kHz ±4.4 dB subwoofer 33 Hz to 61 Hz ±1.9 dB Sensitivity (SPL at 1 meter with 2.8 volts of pink-noise input) front left/right 89 dB center 88 dB surround (Bipole) 88 dB Impedance (minimum/nominal) front left/right 2.4/6 ohms center 4.6/6 ohms surround 4.9/6 ohms Bass limits (lowest frequency and maximum SPL with limit of 10% distortion at 2 meters in a large room) front left/right 40 Hz at 90 dB center 62 Hz at 75 dB surround (Bipole) 80 Hz at 87 dB subwoofer 25 Hz at 73 dB SPL 98 dB average SPL from 25 to 62 Hz 110 dB maximum SPL at 62 Hz bandwidth uniformity 89%
All of the curves in the frequency-response graph are weighted to reflect how sound arrives at a listener's ears with normal speaker placement. The curve for the left/right front channels reflects response of the Synchrony One with the speaker standing on the floor averaged over a ±30° window. The center-channel curve reflects response of the ONE C averaged over ±45°, with double weight directly on-axis of the primary listener. The surround-channel curve shows the response of the Synchrony S averaged over ±60°.
Because the One will always be used on a floor measurements were taken with the speaker on a floor. Both the center and surround channel speakers were measured on a 6-foot stand which gives anechoic results to approximately 200 Hz. All upper channel measurements are taken at a full 2 meters which emulates a typical listening distance, allows larger speakers to fully integrate acoustically and, unlike near-field measurements, fully includes front panel reflections and cabinet diffraction.
The floorstanding One measurements showed excellent low frequency extension followed by a broad response sag that begins with a 250 Hz floor bounce notch and continues up to 2 kHz. Above about 500 Hz there are a number of narrow irregularities, and response begins to fall off at 6 dB-per-octave above 7 kHz. The large tweeter peak at 18 kHz is shared by the One C center and S surround speakers. The One impedance falls to 2.4 Ohms at 70 Hz and also falls below 3 Ohms at 1.2 kHz.
The One C has reasonably smooth response above 80 Hz with no off-axis lobing (unusual for a horizontally arrayed speaker), although response begins falling off at 7 kHz, and the aforementioned tweeter peak is also present. The Synchrony S, like practically all bi-dipole speakers, has plenty of interference patterns as the microphone is moved around to either side of the speaker face (a desirable trait in this type of loudspeaker) and overall response falls by approximately 1 dB-per-octave as frequency rises.
The HD10 Subwoofer bass limits were measured 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 up to 3 dB higher sound-pressure level (SPL).
The subwoofer generally showed limited dynamic capability, except at 50 and 62 Hz. SPL capability falls off at nearly 30 dB-per-octave below 50 Hz. While the crossover dial is marked from 50 to 150 Hz, the actual acoustical turnover frequencies only run from 50 to 61 Hz over the full range of the dial.