Well, I've been in hiding for a while lurking. And then I see this flurry of people on various forums refering to PEAK power!

Hello?

Peak power is a marketing tool derived by advertising departments, NOT engineers. It simply does not exist in physics.

First, 1 watt = 1 joule of energy measured across 1 second in time. (A joule is the amount of energy needed to lift 1 Lb about 9 inches.)

Maybe I need caps for this:

A WATT IS MEASURED ACROSS 1 SECOND IN TIME.

Considering a 20hz tone is in fact 20 wave forms per second, how exactly is measuring the peak voltage of ONE of these wave forms scientific?

Watts RMS is the average power delivered across 1 second in time.(RMS standing for Route Mean Squared)

So you've got an amplifier that says 1000 watts on the front. That's great. In the lab, according to the marketing department, it can produce the equivelant voltage that is properly measured across one second, into ONE waveform. That's your peak power folks, and the rest of the time, (as in the other 19 cycles of that 20hz) it's pushing a real world 200 watts RMS.

Peak power is for NINIES!

Adam

Nice rant ;) [img]graemlins/thumb.gif[/img]

As someone whose occupation is marketing though, I think that peak power is pure genius. It just goes to show you how few consumers are actually informed and how easily their purchasing decisions can be influenced.

[ November 17, 2004, 12:03 PM: Message edited by: Kool ]

We beat this one to death a while back, and I wrote a story on it in PAS..

You are right though, the time base for the measurement of power is 1-Watt.

In reality, I haven't been able to get much more out of an amp or head unit using a single cycle, so to me, there still isn't instantaneous power.

[ November 17, 2004, 01:03 PM: Message edited by: Dave_MacKinnon ]

Peak is always 2x RMS for a sinewave... saying 'peak' power dosen't exist in physics is not correct.. Joules/second is the base term in SI units... 1J in .o1seconds is still 100joules/second for the time frame...

It is worthwhile to know the dynamic abilty of your amp... most test do 10cyles at 1khz..

I think what stinks is arbatrally slapping a # on a amp without saying how it was derived..

your definition of peak power is difference then fosgate's. They seem to think peak power is rms power x 3 [img]smile.gif[/img]

RMS voltage is generally considered to be 0.707 the peak voltage of the waveform.

Dave - were you gated down to 1kHz and loaded to just above where the outputs would smoke?


In reality - the number of watts you have is irrelevant. You either have enough or you do not.

I think companies can do whatever they want/say what they want as long as they say how they ggot there...Even the average person would raise suspicion about an add that says "1000W Peak at 20hz for 5% of the time..."

There just needs to be a STANDARD power/efficiency/THD ect. rating for ALL companies. They all need to be rated the same and then there would be no problems...

man why do they do that to us. cause i for sure dont under stand half that stuff.

agreed, you can get a "200 watt rms" amp to beat the living sh!t out of a "800 watt mac power" amp.

usually this 4extreme is only covered when the 800 watt amp is sony. meaning its rms rating is 1/4 what it says.