No engine sound variation
 

I am getting almost no variation with RPM/manifold pressure changes in the engine sound inside the cockpit of Bf 109s. Only in almost throttle down I can here the engine dropping. Even overreving does not seem to be distinguisable from general cruising operation.
Is this normal or am I doing something wrong?
I did not have this issue prior to the installation of latest patch with hotfix. (old sounds)

Before I start messing around with drivers and replacing hardware, I would like someone to confirm that this is an issue on my end. If that someone has creative gear, so for the better :)