I posted about this on vgmdb, and I thought folks might be interested here as well.

I recently acquired both the Japanese and American pressings of the Donkey Kong 2 soundtrack.  It turns out that on the Japanese pressing, the volume in the left channel is much higher than in the right.  This is the case on every track.  The American pressing on the other hand is balanced perfectly.

Here's a link to a waveform which illustrates the issue: Waveform

Given that the Japanese DKC2 is the most expensive soundtrack out there, the fact that it has such a serious issue is somewhat humorous...

I never understand having to have the Japanese release if the US version is just as complete and there aren't quality issues.  Even if the Japanese press were the same, why pay many hundreds more?

OBI strip

Correct me if I'm wrong, but it's the first DKC OST where there's a gap in recording quality between the Japanese pressing and the American/European, right?

What are we looking at? What's the scale? Off-hand, looks about the same to me.

I could tell the difference looking at the wave forms posted, but you'd probably be hard pressed to notice this when playing the Japanese pressing - even with a good pair of headphones - which is why it probably went undetected for so long.

However, while on this topic, because this would be hard to detect outside a visual representation of the waveform, what made you look at these songs in a music editor? Did you catch this from an auditory standpoint? I'm have to admit I'm curious. I usually only look at music in editors when I need to do work on a given file, like separating things like outros and intros.

For each pressing, there are two waveforms.  The top waveform is for the left channel, and the bottom waveform is for the right channel.

The x axis is time.  As I understand it, the y axis shows how loud the sound is in that channel, at that point in time.  Times with large height are loud, and times with small height are quiet.  For example, on both pressings, the end of the track is completely silent in both channels.

On the y axis, I believe that 1.0 represents the loudest allowable volume.  CDs have such a maximum, meaning that, for example, it would be impossible to make a CD which would blow out your speakers when played at low volume.

Now, for the Japanese pressing, notice that the peaks in the left channel reach near 1.0, but the peaks in the right channel only reach 0.5.  That means the peaks in the right channel are only half as loud.  For the American pressing, this isn't the case.

That's a good question.  While listening to the Japanese pressing, I took out my left earphone (but not my right earphone) to talk to someone.  When I did this, it seemed like the volume in the right earphone was surprisingly quiet.  I then tried listening only to the left, and it was much louder.  That got me to fire up an editor.

While the balance issue may not look meaningful, I can say that the American pressing sounds like true stereo sound, while the Japanese pressing sounds somewhere in between mono and stereo - because the right channel is de-emphasized.  At least on headphones, the difference isn't subtle (IMO).