Are there any proper 2D audio panning solutions in Unity?

So, I've been making a game that requires that a mono audio clip can pan completely from the right channel to the left and vice versa on command. At first, when it seemed I couldn't get any 2D control over audio, I created a mono 3D sound player that would move to the left and right of the listener. This has its own issues with lack of control, but aside from that, the sound ALWAYS plays out of both speakers no matter what I do, even if it's stronger on one side than the other like it should be. I cannot get it to pan far enough so that it plays exclusively out of the left or right speaker.

The solution I've come up with so far, is to create TWO stereo audio clips for this mono sound (lengthy music tracks), where one clip has it playing exclusively out of the left channel, and the other has it playing exclusively out of the right channel. Then I would raise and lower the volume of each to simulate panning (though not the correct way as the center should be 4.5db lower than the extremes, but I'm willing to live with that), hoping that both clips play exactly synchronously. The issue with this is that I have to have data for four audio channels just to pan ONE mono clip. Audio is often the biggest memory/data hog in web-based games, and this seems like a ridiculous solution. It seems crazy that Unity has no 2D audio control at all. My question is, am I overlooking something? Is there a simpler solution? Does Unity have a hidden 2D panning function? Thanks so much for any help people can provide!

Also, for anyone else, check out:

I don't know what you mean by 2D panning, but you can get a mono clip to play out of one speaker only. Just put it in the XY plane of the Audio Listener, and keep it to the left or right of the Audio Listener's Y axis.