Test Bench: Thiel PowerPoint 1.2 Ceiling Speaker System
Frequency response (at 2 meters) front left/right: 83 Hz to 20 kHz ±4.4 dB center: 83 Hz to 20 kHz ±4.3 dB surround: 83 Hz to 20 kHz ±4.3 dB subwoofer: 17 to 56 Hz ±1.8 dB
Sensitivity (SPL at 1 meter with 2.8 volts of pink-noise input) front left/right/center/surround: 90 dB
Impedance (minimum/nominal) front left/right/center/surround: 2.3/3 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: 50 Hz at 80 dB subwoofer : 20 Hz at 78 dB SPL 100 dB average SPL from 25 to 62 Hz 106 dB maximum SPL at 62 Hz bandwidth uniformity 94%
We measured the PowerPoint 1.2 on a flat plane, just as it would be used in a real installation. All 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 the PowerPoint 1.2's response averaged over a ±30º window, with double weight at 30º (the most typical listening angle). The center-channel curve reflects its response averaged over ±45º, with double weight directly on-axis of the primary listener. And the surround-channel curve shows its response averaged over ±60º.
PowerPoint 1.2 The PowerPoint 1.2 has quite uniform directivity, and the response traces for all channel placements are nearly identical. This means it should deliver similar sound to all listeners. The speaker's response trace showed a moderate depression between 1 and 3.5 kHz and a generally rough character above 1 kHz. The speaker's impedance is unusually low, so it is important to use it with an amplifier that can handle such a load without distress.
SS1 Subwoofer We measured the SS1 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 SS1 has better-than-average bass extension and uniformity, producing 102 dB SPL or greater from 32 Hz up at a distance of 2 meters. Maximum SPL of 106 dB was measured at 62 Hz, and the sub achieved 78 dB at its low-frequency limit of 20 Hz, both with within the 10% maximum distortion established as our standard.
Upper bandwidth is limited, although certain side and rear wall compensation settings (which, generally speaking, simply reduce levels as the subwoofer is brought closer to side and rear walls) do allow more upper frequency bandwidth. Users should remember to readjust overall subwoofer level when any other subwoofer control setting is changed.