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How do amplifiers work?

I am looking to gain a better understanding of how amplifiers draw power(wattage), and then send the appropriate amount to the speakers.

I have received different opinions regarding this from several techs. Without getting too techinical, as I am not a technician, can anyone shed some light as to how this all works?

Example: Lets say you have a 300wpc amp, with power hungry speakers(say 87db). You are playing music at a moderately high volume (11:00 on your dial, or -20db). Since the music is filled with peaks and valleys, hi's and lows, how many watts could the amp be drawing during any given post, or peak in the music? Does the draw actually exceed the rms 300 watts instantaniously during a peak. Is this what dynamic headroom is for. Is this where distortion or clipping comes in?

When the wattage or signal is then sent to your speakers, is this the maximum amount of wattage availble at any given time, given the volume setting, with the speakers reacting accordingly? Can an amp sense the power required for any given speaker?

Why do some audiophiles say that 100 clean watts is plenty, where others will say 300 to 400watts is needed to drive the same speaker. Is this because the clean 100watts has plenty of head room? Isn't a speaker capable of reaching its best dynamic heights, with an amp that has wattage to spare?

Thanks, Just Curious
wetcoaster

Showing 1 response by wetcoaster

wetcoaster OP
3 posts
 
Thanks for the great responses!
One thing that still confuses me is the wattage output during peaks in the music. I'm not sure the best way to phrase this, but for instance, during a heavy bass note, combined with any number of other instruments, when a large amount of power is being drawn, does the amp typically send more wattage than it is rated for(continuous rating)? I read one thread where an owner of a Plinius amp rated at 125watts, said that the amp could output, at peak moments, up to 1000watts before clipping. Where as another Plinius amp, which was rated 150w or 200w, clipped at a much lower level. Obviously the 125w amp is of better design, but how does all this work(stored power?, dynamic headroom?), and what is the typical output of most amps, aside from continuous power. Can small (under 100watt) amps, actually output clean, but brief bursts of wattage that far exceed 100watts? and by how much? and how does one know this? I've never see it in the specs I've read, or don't know what to look for.
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