Back in the day, I downloaded FMP. It was a dual-audio release. The first half was in OGM, and the rest was in MKV. I was still using BSPlayer at the time. When I got far enough to switch to MKVs, I was like "wtf is MKV", because it was the first time I had downloaded them. Some googling showed me the light and I installed the Matroska pack. Then it hit me: I couldn't switch audio tracks in BSPlayer for the MKVs, and it defaulted to English audio. I tried to listen to it, but it made my ears bleed, which lead me to find out about CCCP, which solved my audio problems, and I could finish watching the series without killing my ears.
tl;dr The FMP dub sucks.