Test Bench: Atlantic Technology 6200e Home Theater Speakers
In the lab
Frequency response (at 2 meters) front left/right 71 Hz to 17.7 kHz ±3.7 dB center 85 Hz to 17.7 kHz ±2.3 dB surround 124 Hz to 17.1 kHz ±2.7 dB subwoofer 28 Hz to 100 Hz ±2.4 dB Sensitivity (SPL at 1 meter with 2.8 volts of pink-noise input) front left/right 90 dB center 91 dB surround 88 dB Impedance (minimum/nominal) front left/right 4.5/7 ohms center 4.3/7 ohms surround 4.2/6 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 77 dB center 80 Hz at 91 dB surround 80 Hz at 77 dB subwoofer 20 Hz at 80 dB SPL 100 dB average SPL from 25 to 62 Hz 106 dB maximum SPL at 62 Hz bandwidth uniformity 95%
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 6200e LR with the speaker mounted on its' stand on the floor averaged over a ±30° window. The center-channel curve reflects response of the 6200e C averaged over ±45°, with double weight directly on-axis of the primary listener. The surround-channel curve shows the response of the 4200e averaged over ±60°.
Because the LR system will mostly be used with it mounted on its matching stand, which will be placed on a floor, measurements were taken with this system on the 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. All basic measurements were made with all the THX Controls set to THX.
The 6200e LR with stand has a moderate 200 Hz floor bounce notch. There is also a 2 dB raised area between 1.3 and 2.5 kHz, followed by some relatively minor irregularities except for a 5 dB notch at 12.5 kHz. The 6200e C center channel begins off axis lobing at ±22.5° off axis, an effect that is basically hidden with our power averaging techniques. The center channel also has a very moderate downward sloping bass-to-treble balance as frequency is increased. The surround system has a fair degree of response notching and level changes depending on microphone position, which is usually regarded as desirable in a bi-directional surround speaker.
The operating controls on the LR and Center speakers functioned identically for all practical purposes. The Damped Room control increased response by just over 1 dB above 6 kHz; the Reverberated Room control cut response by just over a dB above 6 kHz while the Behind Screen switch increased response by just over 2 dB above 2.5 kHz. The Boundary Compensation control reduced low frequency output by approximately 6 dB-per-octave beginning at 200 Hz.
The 642e SB subwoofer's 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).
While the system has moderate overall dynamic capability, the sound pressure capability is evenly distributed, and the 642e SB will deliver 103 dB SPL or greater at any frequency above 25 Hz.
Although the crossover was rated from 40 to 140 Hz, the actual acoustic range only varied between 56 and 100 Hz. However intermediate marked settings were right on target, and there was no level/crossover function interaction.