ADAU144x Mixers

db10 Question

Jul 22, 2011 00:00

Are there any known issues with mixer volume controls?

I have a problem (not yet repeatable enough to give more information) where mixer gain controls when operated from a range of 0 to -80 dB will give only a very small change in volume.

The problem floats across multiple DSPs in the system but always affects a mixer control.

Thanks

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ADIApproved Reply

Jul 25, 2011 00:00

Hi db10,

This problem looks suspiciously similar to an issue I have seen before regarding non-modulo data RAM access. Could you please provide the exact name of the algorithm in question?

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db10 Reply

Jul 25, 2011 00:00

Brett,

This problem turns out to be a firmware problem on our end. Mixer paths exist for Left to Left, Right to Right, Left to Right, and Right to Left.

Turns out that R to L and L to R which were supposed to be muted, were not. So that when L to L or R to R were adjusted the net effect was to take away half of the resulting sum.

I'll look at the other problem you reference however.

Thanks.

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ADIApproved Reply

Jul 25, 2011 00:00

Thanks for the update. The problem I mentioned previously was related to the partitioning of modulo and non-modulo data RAM. There was a problem a while back where some algorithms were not properly referencing to non-modulo data RAM and somehow it was causing unpredictable results when a control was updated. I don't know the details of it exactly. However, this issue was fixed long ago so I think we can safely say it's not playing a role in your system.

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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

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