ADAU1452 Регулировка громкости и шума

ADAU1452 Volume Adjustment and Noise

Активно 3 Ответы 29 Просмотры 2016-02-30 Общие вопросы

Hi Sir,

 

     We are going to evaluate ADAU1452 in EVB , but we find some noise when we adjust the EQ and Volume at single tone ex: 1k / 500khz input.

     I try to make project as below. I will find the some noise when i adjust the volume or EQ.

     Could you help to check the issue in advance?

 



guest replied
3 Years

HI Justin:

You should expect a noise (step) when you switch all coefficients of a filter, specially if the newer filter curve (transfer function ) is very different from the older transfer function (also please make sure you use safe-load for uploading the newer coefficients, if you don't safe-load, then you would get even more unwanted noises since transitional filters may become unstable). Step noise can be very noticeable when using a tone for testing. There are other filters in the toolbox (index selectable...) that make use of 2 parallel filters and crossfade between them during the transition. These other type of filters are more MIPS intensive and are not recommended for filters that will not need to change at run time.

Please comment.

Miguel

"3676
guest replied
3 Years

Dear Dave,

     I try to change the volume control with SW Slew (RC Acccurate) , here is no noise when i going to adjust the volume.   

     But , it still have noise when i adjust the EQ gain. Do you have any suggestion for EQ?

Thanks for your help.

guest replied
3 Years

Hello Justin,

Did you use the volume control that has a slew? It is slower and does take more processing resources but it does not click or create zipper noise. In some applications the volume control is set during product development and hardly ever gets touched again so a slew-less control is useful. However, if you plan to use the control during normal operation, as opposed to tuning", then use a control with a slew.

You can attach your project if you want me to look into this further.

Dave T

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