Handbrake Audio Issues

[Psittac]

I was hoping that someone could let me know the best way to set up handbrake to produce quality audio.

 

I am having two distinct problems, one is a high pitched static the other a muffled audio track.  Recently it has been one or the other 3/4 of the time.

 

I am using makemkv to get mkv files from disc's and typically the audio on these files is just fine.  Then I use handbrake to convert it to m4v or mp4.  I have taken one specific file and converted it in as many different ways as I can think with nothing more than improvements, no solutions.  I have tried different codec's mp3 aac ac3 and auto passthru.  I have used h264 and h265.  Tried different bitrates and stereo dolby and dolbyII mixdowns.  Nothing works.

 

Can anyone make suggestions or point me to a solid tutorial? Every tutorial I attempt has a different version of handbrake and almost none of them address the static issue, only the muffled sound.

 

Any help is appreciated.