Atlas Sound XLTE owner manual 8.2.2Residual Noise, 8.2.3Volume Level Balancing

WARNING:

Before setting gain structure, disconnect the loudspeaker(s) from the amplifier(s).

2.The basic procedure is to use a test signal and set the first piece of equipment in the signal chain (usually the mixer) so it is just below its maximum voltage output from its specifications as read on the voltmeter, or on equipment’s output meter, or just below clipping as observed on the oscilloscope, or just starting to audibly distort. Without changing the volume of the test signal or mixer, adjust the volume level control on each piece of equipment following, including the power amplifiers, so that each is just below its maximum output. If everything is set properly, you will find that the input volume level controls on the power amplifier will end up being set at something other than maximum. This is normal for a well gain-structured system.

Notes:

A.Due to differences in the capabilities of equipment in the signal chain, it may not be possible to get results exactly as stated.

B.For each device, make sure it is the output and not the input that is clipping.

C.If you are in doubt about this procedure, a good compromise is to set all devices in the signal chain to their 0 dB gain (also called ‘unity gain’) position on the input and output level controls. Then adjust your amplifier input level controls to reduce any residual noise to tolerable levels (See SECTION 8.2.2).

3.Remove the test signal, turn off all equipment, and reconnect the loudspeaker(s). The system is now ready for volume level balancing, assuming you have more than one loudspeaker. If you have only one loudspeaker or a left/right stereo configuration, the system should be ready for use.

8.2.2Residual Noise

XLT and XLTE loudspeakers have high sensitivities. This means that they produce a relatively high volume of sound for a given electrical input. This also includes the residual electronic noise of an audio system. By setting gain structure properly and using high quality, professional electronics with balanced connections, this noise should be at or near inaudibility. Even if less expensive equipment is used, the general quality of today’s electronics should result in a quiet system if the gain structure is set correctly. If residual noise is a problem, gain structure is the culprit - not the loudspeakers. The exception is humming or buzzing. This is usually a problem with ground loops in the system's electronic wiring, particularly with unbalanced equipment. Correcting this type of problem is beyond the scope of this manual.

8.2.3Volume Level Balancing

NOTE: If you are simply using one full-range loudspeaker or a simple left/right setup, this step can be skipped.

IMPORTANT: For these adjustments, you want to maintain the system’s dynamic range that was maximized by setting the gain structure. Therefore, DO NOT TURN UP THE INPUT VOLUME CONTROLS OF ANY OF THE AMPLIFIERS. For example, if you decide that a subwoofer is not loud enough, do not turn up the input volume control of its amplifier. Instead, turn down the input volume control of the amplifier for the full-range loudspeaker.

Once the system gain structure is set, you can adjust the volume level balances. This may mean balancing the volume levels between: HF and LF sections of a loudspeaker in BIAMP mode, a full-range loudspeaker to a subwoofer, multiple loudspeakers, or between main and delayed loudspeaker arrays. The idea is to make the system sound the best it can without using any equalization. This may also be done using acoustic test equipment such as an RTA (real-time analyzer), TEF™ analyzer, or something similar. Always determine the final volume level balance by listening to a variety of known program material. Balancing can also be done entirely by ear if acoustic test equipment is not available. In any case, the preferred method of adjusting volume levels for balancing loudspeakers is to make adjustments using the input level controls (also called sensitivity controls) on the amplifier(s). Alternately if the system has one or more electronic crossovers, their output level controls can be used.

PAGE 30 Community XLT / XLTE Series Owner’s Manual