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the way to remove ADAU1401 pop noise when adjust the volume

SigmaDSP & SigmaStudio ADIApproved Jan 15, 2010 00:00 6 replies Original on forum ↗
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ADIApproved Question
Jan 15, 2010 00:00

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

Audio Signal Processors

adau1401

SigmaDSP Audio Processors

BerndH Reply
Jan 18, 2010 00:00

Hi,

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.

Regards

Bernd

ADIApproved Reply
Jan 18, 2010 00:00

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.

https://ez.analog.com/cfs-file/__key/communityserver-discussions-components-files/396/2bc1ea017d57d73b0d7a9084f29b84a4.bin

https://ez.analog.com/cfs-file/__key/communityserver-discussions-components-files/396/94737f15f93074416f4fcba6363114a1.bin

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.

https://ez.analog.com/cfs-file/__key/communityserver-discussions-components-files/396/0758704f975a4f7a1baf7f480f28ce47.bin

https://ez.analog.com/cfs-file/__key/communityserver-discussions-components-files/396/d50eb156d1a9d033f6691ff22136fa6e.bin

genp Reply
May 15, 2014 00:00

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 ?

Thank you,

Gennady

ADIApproved Reply
May 15, 2014 00:00

HI Gennady:

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.

Miguel

genp Reply
May 15, 2014 00:00

Hi Miguel,

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,

Gennady

EZAdministrator Reply
Aug 2, 2018 00:00

This question has been assumed as answered either offline via email or with a multi-part answer. This question has now been closed out. If you have an inquiry related to this topic please post a new question in the applicable product forum.

Thank you,
EZ Admin