Voltage that drives the speakers

[shaiqbashir]

HI Guys!

well! i have a simple question to u. I know this thing that a microphone provides u with some AC voltage in an audio amplifier. But what is that voltage in an audio amplifier, that goes into the speaker in order to drive it. Is it AC or DC?

Thanks in advance!

 

[audioguru2]

Hi Shaiq,
Audio is AC, not DC.
A microphone produces about 10mV AC. A preamp amplifies it to about 1V AC. A speaker power amplifier amplifies it to 20V AC for 50W into an 8 ohm speaker. These are RMS sine-wave voltages. Peak-to-peak voltages are 2.828 times more.

If you apply DC to a speaker then it will get very hot and maybe burn out. The DC will also cause its cone to move away from its linear center position causing severe distortion. ;D

 

[steven2]

this reminds me of one of my photoflash cap charger circuits from the camera i switch it on and charge the cap up then dump the charge right into a small  speaker and get a big pop sound and it handles it ok