[MU4 Issue] Bass Guitar: Notes played back at inconsistent/unexpected dynamics

Describe the bug
The very first note you click on seems much louder than subsequent notes, and for some instruments (e.g. Bass Guitar), the volume of various notes seems dependent on pitch.

To Reproduce
Steps to reproduce the behavior:

1. Create a new score with a bass guitar (e.g. use Rock Band template)

2. Add a low G (bottom of staff) to bass guitar - can't hear it at all?

3. Add a low A - it's quite loud

4. Click on the A again, not so loud now

5. Click on the G - can barely hear at all until less you jack the master slider right up

6. See error

Expected behavior
A clear and concise description of what you expected to happen.

Screenshots
If applicable, add screenshots to help explain your problem.

Platform information
Windows 10

Additional context
Possibly related but the "gain" adjustment for bass guitar seems very extreme too - I can barely hear anything below about 3, which is towards the top of the slider. Other instruments seem ok. There are lots of pops and crackles during playback too.