Multirate / hierarchy board and sampling rate error

Dear,

I'm doing an audio DSP with filters, compressors etc. with SIgma Studio v4.6, on the ADAU1452.

At first, I had a script entirely written on the main board, with multirate processing and it was working perfectly.

Now, I want to sort the script and I'm using hierarchy boards. I've got an error when compiling ("Incompatible Sampling Rates Detected. Please Verify")

I see several stranges behavior:

On the main, I have a DC source going to a hierarchy board.
The main is set @ 96kHz, and the DC @ 24kHz (which is how I want it to be)
So on the main, and on the hierarchy input, I have 24kHz which is normal.
However, once I go inside the hierarchy board, then the DC inputs changes its sampling rate and goes back to 96kHz.

I can avoid point 1. problem by putting the DC inside the hierarchy board.
When I do that, then I can keep my sampling rate of 24kHz.
However, inside the hierarchy board strange behavior occurs:

On some multiply box, with 2 signals @ 24kHz input, it outputs a @ 96 kHz signal

On some T junction, similar behavior : input @ 24kHz but output @ 96 kHz

I also encounter above problem with a feedback loop and aliases inside a hierarchy board.
The feedback loop in and out is 24kHz, alias input is 24kHz.
However, when I use this alias elsewhere in the same hierarchy board, it changes to 96kHz.

Similar problem as 3. Alias is initialized in a hierarchy board with a 24kHz DC box, but is transformed to 96 kHz when used later in this same hierarchy board.
Using the same main and a different hierarchy board, there is one where the sampling rate is staying @ 24 kHz...
One way to counteract it is to not make Alaiases and use a lot of DC boxes, which I find not optimum

Are all those problems bugs? or do I do something which is not planned by the soft?
Is there some sampling rate display error and I should not look at it?

I hope I've made myself clear enough. If there really is a need for the script, I'll have to adapt it to remove sensitive information.

thanks in advance for the feedback.

kind regards,

Jules

Audio Signal Processors

adau1452

multi-rate

bug

SigmaDSP Audio Processors

multirate

dc

hierarchy

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