RMS VS. actually power rating

[2kgtx]

Ok so the other day I am at work, I am an electrical Engineering Student doing a Co-Op at a company who makes electrical components for amps, cell phones, computers, cars, basically all those little tiny chips. I work the Engineering Helpdesk. I am not very far into my studies of electricity but I have learned that RMS levels are what the Meter reads verus actual power rating and to figure actual ratings you multiply RMS by 1.4 now in a recent post I read that a head unit was rated at 50 x4 but only like 20 RMS how is that possible when I figure this mathmatically I only come to 28?
Please somebody help me figure this out and see what my mistake is.

[Archon_Ninja]

Okay this is as far as i know, correct me if I'm wrong.

There are two main ratings in car audio- RMS and MAX

RMS- is nominal power. Mean regular playing power. When you regularly listen to a song, it plays at RMS.

MAX- is max power at current peak levels. Like when a big bass hit or loud part in some songs.

Company's like to put MAX power rating cause it looks better. So it's capable of 50 Watts Max but it plays at 20 Watts. RMS....

hope thats helps...

[bme107]

Exactly what ninja said. I have never seen or heard of a direct correlation between RMS and Max like 1.4x Look around and check it out, the multiplier might be around that but not the same for every model/brand/type of unit.

[00GTS]

2kgtx, you said the multiplier is supposed to give you *actual* power vs. *metered* (RMS) power (power read from some sort of measuring equipment). What does this have to do with peak power?

I think what you're talking about is something a little more subtle than most car audio heads (including me) would care about.

Anyway, like the others said, when a deck claims to be 50Wx4 they're talking about *peak* power, not RMS or actual.

-Josh

[2kgtx]

Thanks for the replies, I have done some more research on this and have found that RMS is the power seen through a meter and to get its actual power levels you need to muliply it in some formula that has to do with the square root of two. I am not sure what it is I am going to look at some of my circuits books tonight and try and find out. By the way this is a little more than most audio heads would want to know. I am just curious as to how the companies come up with thier ratings.