ENVY24_MT_VOLIDX
envy24_wrmt(sc, ENVY24_MT_VOLIDX, 16, 1);
envy24_wrmt(sc, ENVY24_MT_VOLIDX, 17, 1);
envy24_wrmt(sc, ENVY24_MT_VOLIDX, ch * 2, 1);
envy24_wrmt(sc, ENVY24_MT_VOLIDX, ch * 2 + 1, 1);
envy24_wrmt(sc, ENVY24_MT_VOLIDX, ch * 2, 1);
envy24_wrmt(sc, ENVY24_MT_VOLIDX, ch * 2 + 1, 1);