Here's what I mean by Headroom. ... I think that I'm using it correctly. Quite simply, by looking at the waveform of the converted file, it looks far less compressed (i.e. dynamic range, not file compression) and is normalized to the proper peak levels. Typically in ac3 file compression, the first thing to go is the volume. I think I'm still hearing compression artifacts in some of the louder spots, but it's not what I'd expect for 192.

Meanwhile, I'm still puzzled over the PCM file lengths.