Why are there people out there that think when the volume is down, an amp still pushes power?

Question

This I do not get.

Joe made this statement when he answered my last question, "well that 200RMS is heard at max volume, when its at minimum, its still getting this power from the amp but you won't hear it."

If a sub is getting power but you can't hear it, that's a DC signal.

When an amp is getting no signal, neither is the sub. The power is directly proportional.

Answer 1

I have often thought about that too. I have explained to people many many times that when the volume is down the amp isn't pushing power. This discussion came up after my buddy saw that LED light was on; he thought that anytime that light was on the amp was pushing power to the speakers.

"the power is directly proportional"

^With that statement you lead me to believe that when my head unit is at 100% volume the amp is putting out only the amount of power allotted by the gain? So with my gain tuned at about 200 watts then at 50% volume only 100 watts is being put into the sub?

^ If that make sense is it correct? -If not correct could you explain it to me a little more.

Thanks

Answer 2

it is called ac current it fluctuates due to alot of factors, including frequency, impedance rise,etc. that is why we use rms figures not peak figures to rate amplifiers.

Answer 3

The above is true, the word for that is "efficiency". If you have a cheap 100 watt RMS amp that is 80% efficient (like most MOSFET Class-D amplifiers), at MAX power, and with good voltage, you can only put out 80 watts RMS.

Answer 4

some cheaper amps do draw high amounts of power even though they are not delivering very much to the speakers. it has to do with the type of circuitry involved. cheap always cost more in power.  get an inline amp meter rated above the systems ratings  and hook it in line with several amps(one at a time) and i bet you find at least one the uses almost the same power at zero volume as it does at full power.