why have RMS and Peak Power?

[BenWall]

why do speakers say that there 180watts, when there obviously not, why not just say the RMS and thats it?

 

[jjoe90]

because the watt is what they can jump to [in a way]
and rms is what they can continuously play at
i think im right in saying that

 

[BenWall]

oh ok. thanks for clearing it up a lil

 

[XXXChromeClioXXX]

chavs see the high numbers and say. "me system is eleventy billion watts and it can smash me window init"

No on a serious note

RMS is continous watts the speakers can safely handle but most good speakers can take double there rated RMS on music if the signal is clean

 

[16v_jon]

The high value PMPO is the MOST the speak can handle before blowing

 

[XXXChromeClioXXX]

The high value PMPO is the MOST the speak can handle before blowing

So your saying if you gave a speaker its peak power in RMS on a sine wave it would survive?

Because i know for a fact it wouldn't

 

[mr.k 16v]

forget max watt it means s"*t,its all about the rms.this is the main wattage that your sub and amp can play at.

 

[Dink]

now peak and max are the peak voltage * peak current (in amplifiers)

the problem is they never occur together

RMS (root mean square) is exactly that the square root of the mean(average) squared and is what all normal electrical equipment is measured in

and this is one of my biggest pet hates

 

[dick]

now peak and max are the peak voltage * peak current (in amplifiers)

the problem is they never occur together

RMS (root mean square) is exactly that the square root of the mean(average) squared and is what all normal electrical equipment is measured in

and this is one of my biggest pet hates

current is measured in amplifers is it?

1 of my pet hates is people who think they know what theyre on about as theyve picked it up from someone and think theyre the s**t.

also, to the guy before, wattage aint a word, its "power"

 

[Dink]

no you don't get voltage and current from speakers do you

 

[dick]

what?

 

[Dink]

um i'm not sure if your above post is aimed at me but i do know a fair bit about car audio.

you seem to think i thought current is measured in amplifiers when whai was saying that peak given my amplifier manufactures is peak voltage (might be rail to rail voltage) * peak current

 

[dick]

o, getcha

ye i was gonna say it was well written, just had to pull u up on that bit lol.

sorted

 

[BenWall]

lol thanks boys, its clearer now

 

[mr.k 16v]

now now dick just havin a simple talk,no need to be rude!

 

[theduck]

to answer the original question RMS is the power rating that the speakers/amp can play consistenly PMPO is basically thye point at which the speakers/amp will blow up. I've been in testing labs for an international company while they were doing these tests, and they did literally blow the speaker up to test PMPO.

At the end of the day though guys, it really doesnt matter what your speakers are rated at, as you are FAR more likely to blow a speaker up by under powering it. How? Simply by overworking your amplifier so sending a 'clipped' signal to the speakers. A clipped signal is what causes distortion and this is the MAIN cause of damaged speakers. For those of you that dont know what a 'clipped' signal is I'll explain. Normally an amplifier outputs a sinewave, a sine wave looks like this -

\/\/\/\/\/\/\/\ but smooth and curvy

a clipped signal is when the amplifier cannot make this wave larger and so cuts the peaks and troughs off of the sine wave, hence its called clipping, this makes the nice smooth sine wave look like this -

\_/-\_/-\_/-\_/


Basically, what I am saying is, dont worry about what the power HANDLING of a speaker is, as you are VERY unlikely to blow it up from over powering it. You want a good headunit that provides a clean signal to the amp, a good amp to amplify the signal without clipping and then speakers. You can improve the sound by putting better speakers in, but they will only ever be as good as what comes before it, so basically the head unit should ALWAYS be the best part of the system, then the amp then the speakers. I have run systems - admitedly in home hifi setups - that are fronted by £2000 cd players, then a £2000 pre/power amplifier combination running £200 speakers, and the sound from that was better than any other system I could put together for around £4000!

 

[Dink]

nit picking now lol

but your never going to blow a speaker but under powering it.

it over driving the amp. (which can be done without clipping if you know what your doing and have a CRO:evil

people need to remember the gain is a multiplyer and not some sort of power control

 

[theduck]

underpowering the speaker/over driving the amp are one and the same, just a different way of saying the same thing. You are trying to produce more volume with an amp that isnt capable to therefore underpowering the speakers/overpowering the amp.

 

[Dink]

but a cliping amp is producing more power because a square wave has a larger area that the amp is going to be 'on'.

 

[theduck]

but its producing a clipped signal which is what damages speakers. Think about it, if the signal is clipped enough it will eventually go DC, the most impressive way to blow a speaker up

 

[Dink]

never going to get dc it will be a square wave.

yeah clipping is damaging because it contains more power (nearly double in some cases)

 

[theduck]

clipping doesnt contain more power, it just leaves maximum power on for longer. you can get an amp to go dc, but most amps will blow up before you get them to.

 

[Dink]

yeah if you put dc into them (i'm sure most would die if you did that before it outputed anything).

it cotains more power because it rises at a sharper angle too thus making the wave wider

 

[theduck]

EDIT: I'm gonna leave it at this anyway, isnt the first time we have had a similar debate and it isnt worth bothering with as we'll never agree.

 

[Dink]

lol yeah your right there we never do agree.