Test Bench: DCM TimeFrame TFE200 Home Theater Speaker System
In the lab
Frequency response (at 2 meters) front left/right: 31 Hz to 17.2 kHz ±7.4 dB center: 81 Hz to 19.8 kHz ±3.0 dB surround: 82 Hz to 12.6 kHz ±4.4 dB subwoofer: 39 to 83 Hz ±2.3 dB Sensitivity (SPL at 1 meter with 2.8 volts of pink-noise input) front left/right: 89 dB center (Stand): 85 dB surround (Bipole): 86 dB Impedance (minimum/nominal) front left/right: 2.9/6 ohms center: 3.9/8 ohms surround: 3.5/5 ohms Bass limits (lowest frequency and maximum SPL with limit of 10% distortion at 2 meters in a large room) front left/right: 32 Hz at 79 dB center: 80 Hz at 87 dB surround: 80 Hz at 91 dB subwoofer: 25 Hz at 62 dB SPL 96 dB average maximum SPL from 25 to 62 Hz 112 dB maximum SPL at 62 Hz
All of the curves in the frequency-response graph are weighted to reflect how sound arrives at a listeners ears with normal speaker placement. The curve for the left/right front channels reflects the TFE200's response with the speaker standing on the floor, averaged over a ±30° window. The center-channel curve reflects the TFE60C's response averaged over ±45°, with double weight directly on-axis of the primary listener. The surround-channel curve shows the TP160BDP's response averaged over ±60°.
I measured the response of the center and surround speakers with them placed on a 6-foot stand, which gives anechoic results to approximately 200 Hz. Except for the subwoofer, all measurements are taken at a full 2 meters, which emulates a typical listening distance, allows the outputs of large speakers to fully integrate acoustically, and, unlike near-field measurements, fully includes front-panel reflections and cabinet diffraction.
The floorstanding TFE200 has controlled directivity, along with a fairly deep floor-bounce notch at 260 Hz and a considerable degree of roughness at frequencies above 400 Hz. The TFE60C center channel speaker, despite the offset tweeter, shows some lobing even directly on axis, which becomes much worse as the microphone is moved off center. The bidirectional surround has a noticeable null at 2 kHz that is evident at every listening angle, although the precise frequency and depth varies somewhat depending on radiating angle.
I measured the TB1212 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 measurements reveal that the TB1212 will produce 112 dB SPL at 62 Hz, but its output capability falls off sharply at 30 dB-per-octave below that frequency. (Note that we're talking about maximum output here, not frequency response.) It will, however, produce a true 25 Hz note within our 10% distortion limit, albeit at just 62 dB.
Although the crossover control is specified as 40 to 120 Hz, the actual acoustical high-frequency cutoff varies only from 55 to 83 Hz over it's full range. There is also a 3- to 8-dB reduction in level with settings on the bottom half of the dial.