input gain

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#1 united sound

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Posted 06 August 2011 - 12:21 AM

We have a Vertec 4888 System with I-Tech 8000s JBL's presets come with a 26db input gain, but we need to change the input gain to work with digital consoles output.
does anyone know what the input gain should be on your amps while using a digital console?     after you find the input gain, how do you calculate what the output voltage of your amps should be so we do not blow componets?        

#2 Kevin Heber

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Posted 08 August 2011 - 07:41 AM

Unless I'm missing something, input gain doesn't apply to digital inputs, at least not in the same way.  You almost always just want to use 0dB (unity) gain on the AES input.

The best way to set voltage limits is to ask the speaker manufacturer what they should be.  For the 4888, JBL has filled in some of these numbers on the attached document.  If you get no help from the manufacturer, you can simply use the RMS and peak power numbers.  In the iTech, peak voltage can be estimated by using SQRT(peak_power * impedance).

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