I use MM Codec packet to convert CD and FLAC to M4A format. I always use VBR and 100% quality. Normally, the converted files have a bit rate of around 290 kbps (280 to 310 kbps).
Recently, I tried converting an album from FLAC to M4A. For some reason, the converted files has bit rate of around 520 kbps and double the normal file size for similar length songs. The only way I could get the files to normal bit rate and size was to set the quality level to 45%.
Any idea why the files might be converting in this way?