All numbers are merely indicative.

That should be a standard disclaimer printed in all manuals of AV equipments Smile Oh well, you asked about RMS.

RMS - is an acronym for Root Mean Square. As such Root-Mean-Square is a general concept in school level mathmetics. If you insist much on theory here is it: http://en.wikipedia.org/wiki/Root_mean_square
To keep the matters simple, RMS is used to express the power handling capability of an amp or a loudspeaker system. Notice the phrase loudspeaker system. The RMS value is expressed, generally, is of the whole loudspeaker system and not of a single driver. That makes it easier for consumers to understand the whole system as a whole. Otherwise, an end user will have to know maths and physics to calculate the RMS value of a loudspeaker system.

When a manufacturer says, this loudspeaker's power handling capacity is 20 wrms, he means to says, this loudspeaker (system) is capable of handling 20 watts of power (again, thats a complex calculation, if a load lets 1 ampere of current pass thru given 1 volt, it is said to be a 1 watt consumer, save for loudspeaker load). Simply put, the RMS value is an indication of how much currenton a long-term basis a loudspeaker can take. Notice the phrase long-term basis. Usually, the voice coil of a transducer will be able handle a lot more power on a short-term basis than it can on long term basis. Why? Because, that will be an instantaneous attack (order of a 1000th of a second or so).

Superduck: Max power is not RMS power. Yes, pretty much all amps clip at their peak (max) power. If the specs are correct, they should not be clipping at their highest RMS (program) rating--that's what the extra headroom between RMS and peak is for

htom: Every speaker I've ever bought had a RMS and a peak rating. The advertisment is always the peak, you have to dig into the specs to find out RMS/program.

Xevion and DriverGuru have some good advice, you can almost always hook a speaker up to an amp capable of putting out more power than the speaker is rated for. From what I understand, if your amp hits the most power it can push and starts clipping, it sends a distorted signal to your speaker which can destroy the speaker by tearing up the cone. If you send a speaker too much clean power for an extended period of time, some component in the speaker is going to do the same thing a fuse does when it gets too much power through it--it will melt.

And again for everyone:

RMS = Program = Safe sustainable power rating (the component can handle this for hours)

Peak = Max = The end of safe (the component can handle this for very short bursts without failing)

Don't get the two confused. Anything advertising (the outside of the box, the newspaper ad, the sign in the store) will almost always show you peak power.

One more thing--manufacturers don't necessarily lie in their specs, but they certainly don't tell the whole truth. There is a lot of physics that goes into how much power an amp actually feeds a speaker which includes things like the temperature of the amp, the speaker it's driving, and the frequency being fed into the speaker. For lower quality manufacturers, they'll write down any number they can conceivably hit in ideal conditions. Other manufacturers are conservative in their numbers, so you might actually get *more* than the rated power. As always, caveat emptor. Use Google, look for independent tests before you buy.

Trocki je napisal/-a:Torej, namen imam zamenjat original zvočnike v avtu, ker so čista polomija. Avtoradio sem že dobil in sicer Sony CDX-GT474UM 4x52W.
Kakor sem gledal po internetu, sem ugotovil da spredaj ustrezajo 4" zvočniki, zadaj pa 4" x 6".
Ojačevalca ter wooferja ne mislim vgrajevat, ker nimam take potrebe, hočem da zadeva samo malo bolje špila, ker to sedaj je res tema.
Bo pa cel projekt menjat sprednje zvočnike, ker bo potrebno sneti celotno plastiko od vrat.
Budget je nekje 100€ za sprednje in zadnje skupaj.

Hvala vnaprej za predloge

Mogoče kaj takega za spredaj?

http://zoom-market.si/si/avtoakustika/z ... kt-cl-100/

in tole za zadaj?

http://zoom-market.si/si/avtoakustika/z ... sxe-4625s/

Ivan36 je napisal/-a:Fajn je, da je RMS moč zvočnika enaka moči na avtoradio torej RMS 50W x 4 in max power 120W recimo, tele tvoje so pa komaj 20 W RMS, kar bo spet škripalo in hreščalo