Loudness module generates noise

SigmaDSP & SigmaStudio takumi3952 Feb 27, 2018 00:00 2 replies Original on forum ↗

takumi3952 Question

Feb 27, 2018 00:00

Hello,

Please see the attached loudness module schematics.

Loudness module generate pop-noise, when filter selection was changed by our controller.

This loudness module have Smoothing Feature.

However there are no documents about how to calculate smoothing coefficient.

Please describe how to calculate this slew_mode value.

Thanks and Regards,

Report

ADIApproved Reply

Mar 1, 2018 00:00

Hi Takumi:

Unfortunately, calculating the smoothing factor on a slew between filters is difficult to put on an equation. May I suggest that the customer simply raises the current "12" value in the slew field to slow down the slew rate? A higher value will make slewing slower.

An alternative for what the customer is trying to do is to use the new blend filters. These (currently available for the Sigma300 / ADAU145x / ADAU146x), if properly calculated will save significant amount of memory.