RMS vs Nominal power

[XeSSiV]

hey again..

whats the difference (if there is any)
thanks

ps i think they mean the same thing.. thanks

[StoneX]

Generally, they mean the same thing... When picking and choosing amps and speaker. They also use continuous sometimes aswell.

Technically, they are probably different.

[vztrt]

If you mean RMS and peak than RMS is like the "average" of what the speaker is goin to be running. RMS is more a true indication (and not just in speakers, but power transmission etc).
The conversion is the peak power / square root of two (or peak power * 0.707).

[RVN 355]

RMS root mean squared - 70.7% of peak Vmax = Vrms/0.707 ...

RMS of A.c Provide same heating effect of D.C known as "effective value"

[semi]

you guys are really only talking true AC sine waves rather than music. Music is very different to a sine wave, so you cant calculate the RMS from peak. The way manufacturers use peak is pretty much the largest DC signal that they can send for a very small period of time. Not the peak of the sine waves

[garfa]

you guys are really only talking true AC sine waves rather than music. Music is very different to a sine wave, so you cant calculate the RMS from peak. The way manufacturers use peak is pretty much the largest DC signal that they can send for a very small period of time. Not the peak of the sine waves

yes music is dynamic but a peak is a peak in any sin/cos(/tan) wave.
a peak is just a maxima or minima, inderpendiant of the wave's shape.

[1991_Vn2nV]

If you mean RMS and peak than RMS is like the "average" of what the speaker is goin to be running. RMS is more a true indication (and not just in speakers, but power transmission etc).
The conversion is the peak power / square root of two (or peak power * 0.707).

Nominal is a different rating to Peak. Nominal is similar to RMS but not the same....brands such as Pioneer use Nominal ratings for some of their speakers.
I havent been able to figure out exactly what the difference is but there is a difference. Pioneer claim that a 50 watt nominal speaker should be more powerful than a 50watt rms speaker as nominal is a lower rating than rms in general....but pioneer use nominal ratings alot so it may be bias? But then again they also use RMS

*shrugs* im confused

[garfa]

but remember the power figure really mean sweet **** all in the grand secheme of things .

[Tasmaniak]

Generally, they mean the same thing... When picking and choosing amps and speaker. They also use continuous sometimes aswell.

Technically, they are probably different.

What he said.....^^^^^^^

Dunno about you stonex but everybody else just got me quite confused!

[vztrt]

Nominal is a different rating to Peak. Nominal is similar to RMS but not the same....brands such as Pioneer use Nominal ratings for some of their speakers.
I havent been able to figure out exactly what the difference is but there is a difference. Pioneer claim that a 50 watt nominal speaker should be more powerful than a 50watt rms speaker as nominal is a lower rating than rms in general....but pioneer use nominal ratings alot so it may be bias? But then again they also use RMS

*shrugs* im confused

As soon as that kina stuff comes out think it's a marketing thing. Just go by the RMS output.

[Tasmaniak]

vztrt.....it's the same shit just a different stink.

[1991_Vn2nV]

As soon as that kina stuff comes out think it's a marketing thing. Just go by the RMS output.

But thats the problem...they dont have an RMS output, they give a Nominal output. I think Pioneer do it to deliberately confuse people. They couldnt tell me the exact difference themselves. Why measure their amps in RMS but speakers in Nominal? But yeah i guess they are the same pretty much.

[Tasmaniak]

holy snapping duck shit...do we have to say it again?!

nominal power is equivalent to RMS.

Do we understand that now?!

[goslettandrew]

Couldnt you work out the power of an amplifier by measuring the max current drawn, then multiplying it by the voltage?
Or wont that work in this case

[Tasmaniak]

Couldnt you work out the power of an amplifier by measuring the max current drawn, then multiplying it by the voltage?
Or wont that work in this case

no, that can only tell you the absolute max power that the power supply can deliver. Given the fact that the power supply is ignorantly inefficient (50-80%) it is not possible to work it out from the current drawn. Although if you know your efficeny factor it can be used to give a guideline.

[Garth]

one thing i learnet at school (trade school that is) is the following forumula

p=vi
v=ir

nominal power and rms, my most fravorite subject (followed closely by 3 phase phaser angles)
nominal power is the power out put of any given object, i.e. the power given out by a heater (commonly known as heat loss) may be 1200w, that it 1200 w of power used to created that heat. which means, 1200/230 would give you the current used.

rms is the route mean squared of power. i.e. 1200 w is the rms of the heater used above.

now, this is where it will confuse you. amps basicaly has nothing to do with rms, neither does power aka watts, rms only applyes to the voltage.

there is a nice and simple way of explaing it, ill use a house as my example
your normal every day run of the mill house has got 230v at each power point, each light switch, everywhere, the house is 230v, now that 230v is the rms voltage, aka the actual usable voltage. when you look at the sign wave of the normal 50hz ac system, it is 230 peak to 0, that is 230 positive to the 0 point, then 230 from the zero point in the opposite direction the negative point. when those 2 points combine and go the the rms scale backwards it gives you a voltage of 325.31vac (230/.707=325.31vac) it can be eaisly explalined by this, it is the adverage voltage on a peak to peak system.

so basicaly ignore the the old rms or nominal voltage, there is no different at all. they are both one in the same, just 2 different words. if they were to say var or par then i would question it, cause var and par stand for voltage appraent or power apparnent, then you tog your apparent power wich is total different again.
true power and apparnent power is a even easyer way of doing it, a true power system on 1000 watt amp would be 1000 amps,put apparnt power would be 1414.42 watts of doof doof. it is physicaly imposible to get apparnent power on any applience, it cant not be achieved, it would brake all rules of electrical engernering and the world would be turned upside down and the grass would stop growing and yada yada yada you get my drift

[semi]

yes music is dynamic but a peak is a peak in any sin/cos(/tan) wave.
a peak is just a maxima or minima, inderpendiant of the wave's shape.

I know that, what im trying to say is that you cant calculate RMS from music, because its dynamic. Im struggling to find a way to write this, but you can only use the formula of RMS= peak/root(2) for a sine wave

and btw, a tan wave has no peaks, just vertical asymptotes

[garfa]

well i said tan as a joke. a signal like a tan wave would be UM-possible!
you could calculate the av. power (and rms) of music but it would mean **** all!

[semi]

hahah i feel pretty stupid for not realising it was a joke now, didnt seem to see that smiley face

[RVN 355]

u got it mate frome one sparky to another