I have an automotive headunit system support 4 loudspeakers that using ADAU1401,I would like to understand the way to remove the pop noise when adjust the volumes,thanks
have you tried to insert dc-blocking filter infront of the volume-control? Sometimes ther is a small amount of DC present which causes noise when changing volume.
There are several types of volume control in SigmaStudio. Some are "No Slew." When you update the volume parameter, the gain will change instantly, resulting in the pop sound that you hear.
In order to remove this pop noise, use a Software Slew volume control. When the volume parameter is updated, the value will change slowly or "slew" to the new value. You will no longer hear pop noises.
I've noticed that volume update on a Software slew volume control consists of 2 steps:
- safeload write of the volume value to the target register
- safeload write of the slew rate value to the step register
Is it necessary to update a slew rate on every volume update ?
Does the slew rate write triggers volume update ?
The answer is NO. SigmaStudio just does it because of the way it was coded. In essence the developer decided that it did no harm to write 2 parameters all the time. This implementation of the parameter writing could be debated.
You can try only writing a single parameter by using the Sequence Window. It will take you 2 minutes to verify my answer. Hope you know how to open the sequencer window.
it took me some time to figure the sequencer window out - never used it before.
It's a great tool.
Anyway, you are right - writing of a single parameter works.
It makes my life easier, since I need to constantly update multiple input levels
in order to implement custom audio development algorithm.
And.. I do miss 1442 with hardware slew and simplicity of consecutive safeload writing
Thank you for the prompt and very helpful response,
Retrieving data ...