RMS is the standard for measuring the wattage of audio components, it stands for Root Mean Square and the higher the wattage the more powerful the audio component is. RMS wattage applies to amplifiers and speakers, the RMS watts value of an amplifier states the amount of power that the amplifier can produce and the RMS watts value of speakers states how much power the speakers can handle.

Amplifiers power speakers but can handle several and the amount varies, for in car audio systems 4 speakers is the most common but some can do more and some older models can only do 2. The RMS power of an in car audio system is usually stated like 4x30 watts RMS, this means that the amplifier can power 4 speakers at 30 RMS watts each.

The RMS value of speakers is more simple as they are usually just a simple figure such as 30 watts RMS, in theory this should match or be higher than the RMS power output of the amplifier in your car audio system, if the speakers cannot handle the power of the amplifier you will get distortion of the sound when you go above the power capacity of the speakers and could even cause damage.

So when buying an in car audio system you should make sure that the speakers have enough RMS power to handle the amplifier, when buying speakers for your car you should generally get speakers that have more RMS power than the amplifier as this makes sure that the speakers will have no trouble handling the power of the amplifier.

If you are looking to buy an in car audio system then we have included some below, there are more specific choices in the menu on the right.

	Name	Price
	Sendai CD688 CD Player , audio/car, car, cassette, cd, cdr/rw, halfords, player, players,... Shop: Halfords	£39.99
	Goodmans GCE2813PLL In Car CD Player or Radio , &bull, 24studio, 40w, 4x, antishock, band, cd, cd/cdr/cdrw, classic, d16cm, flat, fold, h5, leisure, load, mp3, mw/fm, panel, player, players, pll, pop, power, radio, rms, rock, slot, system, w178... Shop: 24Studio	£44.99
	Black Car Shaped Radio/CD Player , accessories, car, cd, diy, novelty, player, shaped, single, tools... Shop: DIY Tools	£49.95
	Goodmans GCE2813PLL In Car CD Player and Radio , &, &bull, 24studio, 40w, 4x, antishock, band, car, cd, cd/cdr/cdrw, classic, d16cm, flat, fold, h5, load, mw/fm, panel, player, pll, pop, power, radio, rms, rock, slot, sound, system, vision, w178, x1... Shop: 24Studio	£49.99
	Ministry Of Sound MOSCA11OMP3P In Car CD Player and Radio , &, &bull, 2¼, 24studio, 40w, 7¼, 7"e, balance, bass, carry, case, connector, controls, d18cm, detachable, electronic, fader, fm/mw, front, h55, incar, iso, panel, pll, power, sound, treble, tuner, vision, volume, w188... Shop: 24Studio	£49.99