Background hissing form analog output module

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Background hissing form analog output module
#1
Hi,

I'm having trouble with the quality of the sounds that play through the analog output module I'm using. The module is connected to a digital amplifier which is connected to a speaker, and there's a loud background hissing all the time. Do you know how I can fix this problem? Is there a way to scale the sounds up so that the amplifier can be turned down? 

Thank you!
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#2
Hi Veronica,

The amplitude of the sounds you play is determined in code. Units of the sound data sent to the loadSound() method of the AudioPlayer class are volts (not normalized) so the vector [.1 .5 -1 2] will play four samples at the current sampling rate, of 100mV, 500mV, -1V and 2V respectively. Standard line-level audio signals range between -1.4 and 1.4V. Depending on your audio amplifier, you may be able to safely scale your sound data to +/-2V without saturation.

I hope this helps,

-Josh
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#3
(01-24-2019, 05:36 PM)Josh Wrote: Hi Veronica,

The amplitude of the sounds you play is determined in code. Units of the sound data sent to the loadSound() method of the AudioPlayer class are volts (not normalized) so the vector [.1 .5 -1 2] will play four samples at the current sampling rate, of 100mV, 500mV, -1V and 2V respectively. Standard line-level audio signals range between -1.4 and 1.4V. Depending on your audio amplifier, you may be able to safely scale your sound data to +/-2V without saturation.

I hope this helps,

-Josh

Hi Josh, 

Thank you. I can't figure out how exactly to scale the sound data. Where in the code do I specify the frequency of the sound I want to play, and then where do I scale all of the sounds I have determined? Thanks again!

Veronica
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#4
Note: This thread was resolved with a site visit. The distortion was caused by an incorrectly soldered 3.5mm audio connector.
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