Quick question (What Watts)

[MasterWu]

Havent been in to car audio for ages! Lost a lot of the knowledge i used to have (pushed out by new stuff no doubt!)

Anyway, If an aftermarket Headunit has 4x45W output, would it run a set of components nicely that have an RMS wattage of 70w?

Are Headunits advertised with their RMS or Peak wattage?

Obviously running the comps with an amp would be the best plan, but would they sound good if they are run using the head unit only?

Cheers

[jaye944]

Somone's bound to disagree with this, but here goes.

In real world, RMS is worked out by putting a sine wave into a speaker and calculating the "Root Means Squared" component i.e. the RMS figure.
However music as we know is not an exact sine wave and calculating this is not easy. (I've put a brief explanation below)

Peak power also sometimes rate MUSIC POWER I've found is usually a better way to work out WIKI has a good article on it here
Audio power - Wikipedia, the free encyclopedia

OK in the real world the RMS power rating of the amplifier should be as close as possible to, but not exceed, the power rating of the speaker. By using as powerful an amp as safely possible, the risk of driving the amplifier into clipping is reduced, thereby ensuring that the speakers will receive clean undistorted power.Simply stated: clean power - GOOD, distorted power - BAD.
Amp/speakers power question
{source: Cerwin Vega}

Distortion kills speakers !

HTH


‡If the waveform isn't a pure sine wave (like a square wave or a signal with mixed sine waves of different frequencies or music), multiplying the peak times .707 will not give an accurate RMS value and therefore will not give an accurate indication of the work that the waveform can produce when driving a load. For more complex signals, you need a meter that will calculate the RMS value from a set of samples taken at regular intervals.

In common use, the terms "RMS power" or "watts RMS" are erroneously used to describe average power. A 100 "watt RMS" amplifier can produce a sine-wave of 100 watt average into its load. With music, the total actual power would be less. With a square-wave, it would be more.

Havent been in to car audio for ages! Lost a lot of the knowledge i used to have (pushed out by new stuff no doubt!)
Anyway, If an aftermarket Headunit has 4x45W output, would it run a set of components nicely that have an RMS wattage of 70w?
Are Headunits advertised with their RMS or Peak wattage?
Obviously running the comps with an amp would be the best plan, but would they sound good if they are run using the head unit only?
Cheers

[jaye944]

so to answer the question, yes it will no problem ... BUT.. at higher voilume levels it will distort, the distortion has a DC component, DC into a AC speaker = BAD, bear in mind that 45watts RMS, WONT actually put out 45watts, could be more, usually less.

and all speakers/head units will state RMS, PEAK and somtimes MUSIC or TOTAL POWER,

If an aftermarket Headunit has 4x45W output, would it run a set of components nicely that have an RMS wattage of 70w?

Are Headunits advertised with their RMS or Peak wattage?

Obviously running the comps with an amp would be the best plan, but would they sound good if they are run using the head unit only?

Cheers

[Dom]

Converting RMS to peak is pretty easy.

Take the RMS power, multiply by 1.41 then add some random number between 100 and 10000 and you have your "peak power" lmao

[MasterWu]

Thanks for the replies!

[jaye944]

Yes but that only works on a PURE wave i.e. SINE or SQUARE,
music is NOT a sine wave

Converting RMS to peak is pretty easy.

Take the RMS power, multiply by 1.41 then add some random number between 100 and 10000 and you have your "peak power" lmao