    - .
  20.    50 .

   :
240000   12 .
120000   6 .
m_nFreqSpeed / 50  .
882   44100 
312,5  
(300 RPM = 5   ) 1  = 3125  () - 5 = 15625   

   .
1.   .  m_nFreqSpeed  .
2.  . 44100 .
3.  . 6 
4.    5 . (300 /.) 15625  Periodic  .
5.     . 50 (  .)