Audible noise issue

Hello Eliott,

If you are bringing in another source that is NOT using the same master clock then you will have some issues with clicks and pops.

If you are using the same clock and have the core running at one rate, like 48kHz, and give it a 44.1kHz signal, the serial port will be running at a slower rate. This means the core will be picking up some samples twice and this causes distortion.

where is the MCLK to the DSP coming from?

I guess the DSP (12.288MHz/24.576MHz) and I2S streaming device (11.289MHz) are running at their own MCLK, Is that right? Please explain a little about MCLK sources.

Eliott said:
input I2S sampling freq. : 44.1kHz

output I2S sampling freq. : 48kHz

According to this info, since the serial input port (44.1KHz) and the DSP core (48KHz) run at different sample rates, you may experience some clicks and pops because of the sample rate mismatch.

You MUST use the ASRC on the input side to convert the serial input rate to the core rate. The ASRC will do the conversion and the audio will just be fine.

I don't know about your clocking and signal routing since you didn't attach your project, it's always recommended to attach your project so that we can have a quick look and make the required modifications for you.

So, I assume you are using serial input port 0 and set up the ASRC registers. Please refer to the below screenshot.

I have selected serial input channel 0/1 just for an example, you have to select which channels (and ports) you are using among the 48 channels.

If you still have a problem, then kindly attach your project and explain a little about your clocking, maybe a block diagram would help.

Regards,

Harish

Hi Harishgowtham,

Thank you for your feedback.

I am concerned that my customer information will be exposed.

If I post a block diagram and circuit diagram with a screenshot, is it true that it will be exposed?

I also wonder if confidentiality is guaranteed if I attach my customer files.

Please check. Thanks a lot.

Best regards,

Eliott

Hello Eliott,

No problem, if you are not willing to share the files in an open forum, then please PM me.

Please send a friend request so that I can respond to your private message.

Regards,

Harish

Hello Harish,

Done.

Regards,

Eliott

Hello all,

This issue has been resolved by using ASRCs in the input side.

Regards,

Harish

Hi Harish,

I'll send the block diagram with host AP and wave file using DM message.

Please check.

BRs,

Eliott

Hello Eliott,

Make sure to go into your profile settings and change them to allow direct messages from anyone, or send Harish a friend request.

I have this happen often, I have my profile set to accept messages from anyone, so I get the message then I cannot reply because the other person's profile will not allow it. So do either of those two things and Harish will be able to respond to you.

Thanks!

Dave T

Hello Dave T,

Thank you for your kind answer.

I modified my profile setting. and it is already friend both Harish and me.

BRs,

Eliott