Behringer TRUTHB2092A manual Audio Connections, Adjusting room compensation, Phase adjustment

TRUTH B2092A

making any changes, and then using the controls to finetune the settings, creating the best results possible. Therefore, first set the controls to the neutral position labeled TYPICAL, i.e. set PHASE to 0° and ROOM COMPENSATION to 0 dB.

Start by placing the subwoofer roughly in the stereo center of your loudspeaker system. If the frequency response is not well- balanced, move the subwoofer to the left or to the right, so that it excites different room modes. Also, experiment with different distances to the wall and to the room’s corners. If you place the subwoofer in a corner, the bass level will be increased, changing the overall settings. When selecting a location for your subwoofer, make sure that the openings in the back of your B2092A are not covered.

The stereo/front loudspeakers should be placed symmetrically with the same distance to the listening position. Correct placement of near-field monitors is explained in detail in the TRUTH B2030A/ B2031A user’s manual and in the TRUTH B2030P/B2031P handbook.

3.3.1 Adjusting room compensation

Fig. 3.3: Room compensation

After you have found an optimal physical location for your B2092A speakers, use the switches in the back to finetune your settings.

The ROOM COMPENSATION switch lets you lower the bass range in 2-dB increments. If your B2092A is located near a wall or in a room corner, the sound is reflected back from the boundary and superimposed on the directly dispersed sound. This results in a higher volume, which can be neutralized using the ROOM COMPENSATION function.

3.3.2 Phase adjustment

Fig. 3.4: Effect of phase differences on the frequency

response

When installing the B2092A, a phasing deviation between the subwoofer and main speaker signals may occur. This deviation (phase difference) is easily audible in the sound. Improper phasing causes a dip at the crossover point. Phasing differences occur when the distance between the subwoofer and the audience varies from the distance between the main speakers and the audience—hence having a varying delay time. This can not always be avoided. Using the PHASE function, your B2092A can perform a phase adjustment electronically. Figure 3.5 shows the possible results of phasing differences on the frequency- response curve.

For optimal system calibration, we recommend using a Real Time Analyzer, e.g. the BEHRINGER ULTRACURVE PRO DEQ2496 coupled to a ECM8000 measurement microphone. If no such equipment is available, you can try making an adjustment using an 80-Hz sinus tone:

Run the sinus tone simultaneously on the subwoofer and the front loudspeakers. Set the PHASE switch to the position in which the sound with the highest volume is being reproduced.

If you are working with the DEQ2496, place the measurement microphone in your audience at the height of a human ear. Run pink noise through the speakers. Keep an eye on the 80-Hz range on the frequency display. If you notice a dip in this frequency range, put the PHASE switch into a position that causes a straight frequency response curve, as shown in fig. 3.4 (the graphic on the left).

4. AUDIO CONNECTIONS

The audio connectors of your B2092A are electronically balanced and ensure automatic hum and noise reduction.

Of course, you can also connect equipment featuring unbalanced outputs. To this end, use either mono jacks or connect ring and sleeve of the stereo jack (bridge pin 1 and pin 3 when using XLR connectors).

+Please ensure that only qualified personnel install and operate the B2092A. During installation and operation the user must have sufficient electrical contact to earth. Electrostatic charges might affect the operation of the unit.

Fig. 4.1: XLR connections

Fig. 4.2: 1/4" TS connector for the footswitch

8 4. AUDIO CONNECTIONS