Bugfix: Instruments in game audio at incorrect levels (Diddy Kong Racing)

What steps will reproduce the problem?
1. Begin game of Diddy Kong Racing.
2. Do challenge races against Taj (elephant genie in hub world).
3. Listen to the race music. (Definitely the plane challenge, possibly
others, if the music is the same).

What is the expected output? What do you see instead?

Mostly this works fine, but I noticed that the levels of the various
instruments are incorrect.  There is a lead instrument which enters at one
point which you can hear but at a much lower relative level than when
played on the console.

What version of the product are you using? On which system and loader?

Beta 1.1, Wii 4.2, HBC 1.0.6.

Please provide any additional information below.

I could be wrong about this, since I haven't tested it directly against the
original recently but I spent a large portion of my childhood playing this
game.  The effect is quite drastic, since I was getting geared up in
anticipation of a certain melody only for it to never really come to the
fore.  This is like failing to sneeze.  I've also noticed this on several
other tunes, but it was most obvious with this one.  So while my methods of
research are scientifically lacking, I am pretty confident that the sound
is slightly messed up.

Original issue reported on code.google.com by alain...@gmail.com on 15 Apr 2010 at 12:42

star94star / mupen64gc

Bugfix: Instruments in game audio at incorrect levels (Diddy Kong Racing) #246