Using Performance Manager; Performance Manager Readings - JBL VTX Series User Manual

13.2 USING PERFORMANCE MANAGER

When in the field, the Test System Mode in Performance Manager can be used to test an A12 system. This test method is quick and
especially useful for determining whether all the speaker cables, including cabinet-to-cabinet NL8 jumpers, are properly functioning.
To perform the test, Performance Manager uses the I-Tech HD's built-in noise generator, in conjunction with the amplifier's current draw
and voltage-sensing capabilities, to generate a nominal load impedance reading for each amplifier output channel. Since broadband
pink noise is used as the test stimulus, the returned value is considered to be an impedance value, and it will differ from the resistance
values given earlier in this document (which are taken using DC voltage as the stimulus). `
STEPS:
1
• Make sure Performance Manager is online and connected to the devices.
2
• Navigate to the Test System Mode and make sure all speakers are muted.
3
• Switch the Noise Generator to the ON position and set the level to a value between -30 dB and -10 dB. Values lower than -30
dB may not be sufficient to trigger a reading.
4
• Unmute the speaker or a bandpass to start the measurement. The measured value is displayed on the speakers.

13.3 PERFORMANCE MANAGER READINGS

Below are the expected impedance values for a single VTX A12, a circuit of two A12 cabinets, and a circuit of three A12s. The measure-
ments below were taken at room temperature with a cable length of 25 m (82 ft). Acceptable tolerance is +/- 0.5 Ω.
1 x VTX A12
Variances in temperature, cable length, wire gauge, and usage can make the measurements recorded by Performance Manager more
susceptible to drift. However, variations in conditions like temperature are common across all similar circuits of a system. More important
than the individual component values is consistency across similar circuits. For example, all three-cabinet circuits for an array should
measure similarly. If one is off by several ohms, there is likely something wrong with that specific circuit.
VTX A12 | User Manual
2 x VTX A12
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3 x VTX A12