[LAU] How is the bass mixed? Per-channel frequency analysis? Histogram?

I have a collection of FLAC files, all ripped from my CD collection What I would like to do is run an analysis across all the music to determine how the bass/lower frequencies are generally mixed. For example, how much content below (for example) 150 Hz is on the left channel versus the right channel? I'm not sure if "histogram" is the right word, but in my mind what I'd like to see, per-channel, is something like this: 150--125 Hz: x samples 125--100 Hz: y samples 100--80 Hz: z samples ... Then I can look at the two channels of a song, and if the histograms are approximately the same, I can assume the bass was mixed equally to both channels. I am a programmer, and thought it would be easy to quickly hack something up that would do this, but I have no experience with signal processing, and as I started reading about this, I quickly got in over my head! So I was hoping there might already exist a tool that has this functionality. Note that I don't need any kind of graphical output, as this needs to be wrapped up in some kind of batch processing script---I have about 11,000 files to analyze! The motivation for this is: I have a hardware DAC (digital audio converter) in one part of my house, and a subwoofer in another. There is a single coax run between the DAC and subwoofer, so I can only send one channel. If the overwhelming majority of my music has the bass mixed equally, sending only one channel isn't a problem. But if I choose the "L" channel to send to the sub, and much music has the bass mixed only to the "R" channel, then I won't be able to hear the low frequencies. I want to find out how often this might happen. Thanks, Matt