Need help removing poping sound

SigmaDSP & SigmaStudio stuart.oreilly@hills.com.au Nov 20, 2019 00:00 1 replies Original on forum ↗

stuart.oreilly@hills.com.au Question

Nov 20, 2019 00:00

Hello,

I am new to DSP's and I have inherited a project that i need to support. I have included an image of the audio path below with the area of interest highlighted.

We are currently using an ADAU1462 dsp, and we are using the safe load method to load the values into the DSP (using the SPI bus).

My problem is, when I have the delay enabled (to any value) and i have the compressor enabled (with hold>0), when i change the compression ratio rapidly (being 1-2 times a second), after a couple of seconds, I will get a 'POP' on the audio output. If i change the compression ration slowly (being 1 value every 2 or more seconds), there is no pop.

When i am changing the compression ratio rapidly, i am increasing(or decreasing it by point 1 of a value.

e.g. compression ratio = 10:1 then I increase it and it becomes 10.1:1

I would appreciate any guidance as to how i can either fix or debug this issue.

Thanks

Regards

Stuart

Audio Signal Processors

sigma studio

sigmastudio

SigmaDSP Audio Processors

adau1462

Report

DaveThib Reply

Nov 21, 2019 00:00

Hello Stuart,

For debugging purposes, add some switches that allow you to bypass the compression and the delay. I want to rule out where the source of the pop is. So even though you might not have the compressor in the circuit, see if you still get a pop? Then see if the delay is out of the audio path do yo still get it?

So you are changing the spline curves to change the ratio?

Are you changing all of them at one time? There are too many for safeloading all at one time and you do not need to use the safeload for the compressor. On the older parts you had to use it to prevent clicks or pops but this should not be the case for this processor. Also, safeload is important for updating filters but few other things need to use it.

I think you are writing that often to slowly make changes to avoid audible issues correct? So when changing from 2:1 to 10:1 you will do it in many small steps?

Does your product have the ability to change to a few fixed ratio values or does it have a continuously variable control?

It would be handy for you to send over a project that show the problem.

Thanks,

Dave T

Report