I posted this before and got a response, but the speakers are again playing softer and softer. I have an HP envy M6 notebook PC. It has been gradual but the external sound has been getting softer and softer. I now have to put the sound to 100 to hear it. When using headphones, the sound is fine. I went into settings, control panel, sound/communications and clicked "do nothing" but that only worked for a brief time. My product # is Product number: C2N76UA#ABA. Any help would be appreciated. 
Kathy