M4A files are Apple Lossless or the lossy AAC files. These 96k files are likely Apple Lossless (although you might be accidentally stating 96k as the bitrate, in which case they are mp3-like low rez 96k AAC files, like found in early itunes downloads). I'd convert to AIFF if I were you, regardless (unless they are truly older iTunes store downloads..then they won't play outside iTunes anyway).
Also, platting is not a BDP-1 strength.

(just kidding, but your title needs a typo fix).