Help with Expander for SigmaStudio +ADAU1452
Hi，
We use the Standard RMS module to aplly an Expander with the SigmaStudio on ADAU1452. As shown below.
General understanding, we think the expander related to threshold.When the signal is weak and below the threshold, the expander begins to reduce the gain of the signal. When the signal is equal to or above the threshold, gain attenuation is not applied to the signal.
But in fact we applied Expander by adjusting the threshold and the audio output did not change at all. When the compression ratio of this module is set to 100:1 at the same time, adjust the expander ratio and threshold, the audio output will change.
But not the expected result. We think that the expected result is when the signal is weak and below the threshold, the expander begins to reduce the gain of the signal,When the signal is equal to or above the threshold, gain attenuation is not applied to the signal.
Did we choose the wrong algorithm module?
Audio Signal Processors
adau1452
software
expander
SigmaDSP Audio Processors
Hello Mia,
You are doing nothing wrong. If you look at the actual gain factors on the compressor curve parameters that are being generated by SigmaStudio you will see that there is a significant bug. It would take a while to explain all about this but you need to know what to do to work around this. This issue came to our attention just recently and we discussed it on this post:
Microphone -20 dB stop - Q&A - SigmaDSP Processors & SigmaStudio Dev. Tool - EngineerZone (analog.com)
I also offered a solution which is to use a different compressor out of the library.
Like I said earlier, you are doing nothing wrong and your understanding of how it should be working and what the controls should be doing is correct. The issue is that the SigmaStudio GUI is producing the wrong gain factors.
Dave T
Hello Dave,
For the issue the SigmaStudio GUI producing the wrong gain factors, do you plan to release the SigmaStudio GUI new version to fix it?
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