Stereo watts

If you have to ask, it's not enough.

In the original Prius, it was 45 Watts per channel (see here: http://priuschat.com/forums/gen-ii-...ofer-replacements-improve-things.html#post751). I don't know what it is now; there's nothing in the manual, and even the repair manual only lists Ohms (looks like about 2Ω for the 8-speaker systems, and 4Ω for the others - but that doesn't tell you anything about the power).

If you want a number to throw out at your friends, it ain't gonna be enough. Otherwise, get in your car, crank the stereo all the way up, and see if you can stand the volume - my wife starts complaining when I get it to about 13 (at least for some music), and I know it goes MUCH higher than that...

Keep in mind that every 3 decibels louder the system is, the speakers are double the power. So say you upgrade a 45 watt speaker to a 360 watt speaker; it'll be 9 decibels louder.

 

If you have to ask, just make up a number. Being able to shake the car next to you is not a virtue.

Also 9 decibels louder is about twice as loud. 6 times the power input for 2 times the volume.

 

In audio world 3dB equals twice as loud, in the RF world 3dB equals 1 s unit of signal increase at the recieve station.
+3dB is double the power, -3dB is half the power!

 

Just a notice the amplifier watts (like 4x45W) are usualy peak values. Sinusoid 4x45W inside the car will easily destroy your ears.

 

The ONLY true standard of audio out is RMS, anything else is a sales gimmick......

 

I don't want to get too geeky, but the true measure is SPL (sound pressure level) in deciBels (dB), with an acceptable amount of distortion, such as 0.05%.

Translated: How loud the system gets without distorting. A watt will not tell you how loud the system is, nor how distorted it is. To measure SPL, you use an SPL meter. If you don't own an SPL meter, download a free SPL app for your iPhone and use it to determine how loud your system gets. Measuring distortion is another story, but you can at least turn the volume up on some very clean music to the highest level you can get without audible distorion, and measure the SPL with your phone.

Yes, this is vastly better than the wattage rating! Wattage is not very useful, especially since, these days, there are a lot of digital, Class D amplifiers which are vastly more efficient than the Class A/B/C amplifiers. A 50 watt Class D amp will drive much higher SPL than a 100 watt Class A amp.

 

http://priuschat.com/forums/attachment.php?attachmentid=33640&stc=1&d=1323389548

 

Unhhh, NO it's NOT! SPL is a result of XXX number of RMS watts driving a speaker system of XXX% efficiency! That's why different mixes and matches of crossovers and speakers produce different XXX dB's of SPL. That's the whole point of having a true RMS rating of an amplifier, no matter what class it runs. It gives you a absolute reference point to build your system. Yes Distortion and noise floor of the amp come into play. But known power is the starting point!

Amplifier classes are
Class A - 100% of the input signal is used. It works in its "linear" range all of the time.

Class B 50% of the input signal is used the active element works in its linear range half of the time and is more or less turned off for the other half. In most class B, there are two output devices , each of which conducts alternately (push–pull) for exactly 180° of the input signal. These amplifiers are subject to crossover distortion.

Class AB Here the two active elements conduct more than half of the time as a means to reduce the cross-over distortions of class-B amplifiers. In the example of the complementary emitter followers a bias network allows for more or less quiescent current thus providing an operating point somewhere between class A and class B.

Class C Less than 50% of the input signal is used (conduction angle Θ < 180°). The advantage is potentially high efficiency, but a disadvantage is high distortion.

Class D These use switching to achieve a very high power efficiency (more than 90% in modern designs). By allowing each output device to be either fully on or off, losses are minimized. The analog output is created by pulse width modulation ; i.e., the active element is switched on for shorter or longer intervals instead of modifying its resistance.

What good is having a 1000 watt amp, cranking at full blast in a confined space. Your ear will produce so much wax to protect itself you will eventually have problems hearing! At some point it will become painful, and when your ears bleed, that's when you need to drop the dB's!
If I were building a system I might want to base it around a known reference of power amplification like a AB Class amp of say, 100 watts RMS. With the proper crossovers and speakers, it will more than rock!
More than enough to kill your hearing!!!

 

Ok, sure.
An instrumented, repeatable measurement of audio volume is unimportant, but an arbitrary, undefined, variable measurement is. <-- (That is sarcasm).

Amplifier wattage measurements are total BS. You can buy a 200 watt amp for $60 or $2,000. The $2,000 amp will drive a much larger speaker to a much higher volume level.

 

You really don't have a clue about audio do you........????

Do you actually work in at a job where audio, is important?
The number of HI END Studio Audio installations I have done over the years kind of gives me an edge here, I have been building, maintaining, setting room dynamics for over 30 years!

Or do you only do cars as a hobby?

For one...PRICE HAS NOTHING TO DO WITH RATED OUTPUT!

Pretty much any GOOD amp manufacturer, I.E. Crown, JBL, Maranatz, Pioneer, BGW, Phase Linear, Sony, if they state their amplifier will do 100 watts RMS, it will test out at 100 Watts RMS, PERIOD!
That's why there are standards in amplifier construction.
Crossovers, and speakers, have inherent losses and variables in construction, that's why while manufacturers may have specifications they are trying to achieve, speakers will vary from one manufacturer to another! Hell they may vary slightly from one lot to another. While Sony may make a excellent speaker that takes 100 RMS WATTS to produces a SPL of XXX dB's, Klipsch might have a better speaker that takes the same drive specs, 100 WATTS RMS, but their speaker might put out XXX+28 dB's of SPL. It will be a much more efficient system. While ALL amps that are rated in RMS produce the same power output with a input signal set to a specified level, speakers and crossovers final SPL level WILL vary from manufacturer to manufacturer.
That's a simple fact in the world of audio.
That's why there is such an wide selection of crossovers and speakers, to choose from, they all DO NOT SOUND THE SAME. The only way a speaker system can be precision evaluated, is with known input levels, an Anechoic Chamber, a PRECISION Calibrated Microphone, and a good software program that will show you the results, realtime!. You then measure how much SPL you can get out of the combination of components chosen, you change speakers, or crossovers, you are going to get a different value. Not only is SPL affected, but even MORE important, Frequency Response & Distortion of the system can be determined. Maybe in car stereo SPL rules, in the professional world, it's just a part of the overall equation!
What part of this not clear to you?
When a manufacturer rates a product it is done to a known standard set by SMPTE, or THE DIGITAL AUDIO STANDARDS COMMITTEE, or RED BOOK, or whatever committee is responsible for the setting of Audio Standards of Audio components! That's why the boxes and install sheets have the items ratings printed on it, somebody tested it, and here are it its specifications!
If all you are looking for is SPL and not bothering with Frequency Response, Dynamics, or proper balance of the system, all you are going to get is a loud load of sound, that sounds like CRAP!

 

Dude, I was being sarcastic.

 

I find sarcasm doesn't work here

All things being equal watts all that matters. Speaker efficiency, placement, distortion make things unequal.

If someone has measured the spl at the drivers head before distortion gets too bad on some typical tracks that would be the most helpfull number.

If its not load enough ad a subwoofer, and a hpf to the speakers. That will likely get rid of some of the distortion.

IIRC the JBL is 440 watts x8 speakers which are actively crossed. That makes it about 110 watts per pair of components that act as one full range speaker, which would be plenty loud enough for anyone if they like the sound and the speakers are efficient.

 

Oh, excuse me, I didn't realize that I was speaking to Mr. Expert.

Since you're an Expert and you saw fit to insult me, then please tell me the name of the industry standard for measuring amplifier wattage and THD. You say it exists, and you say you're an expert, so please direct me to it.

I await your Expert reply. Thanks!

 

Just to quickly name 2...

1 - FTC standard, established by the Federal Trade Commission, requires a manufacturer’s stated power rating must be met, with both channels driven, over the advertised frequency range – usually 20 Hz to 20 kHz – at no more than the rated total harmonic distortion (or THD).
2 - EIA rating, established by The Electronic Industries Association, reflects the power output for a single channel driven at mid-band – typically 1 kHz – with 1% THD clipping.


Any other questions....?

Oh, me too....

 

What are the numbers of the FTC and EIA documents? I'd like to read them.

 

Dude Bing 'em, try "CEA2006 TESTING & MEASUREMENT METHODS FOR MOBILE AUDIO AMPLIFIERS ".
This one is specific to Car Amplifier installations,
It makes for a good read!

 

I recommend the Pyramid PB717X $49 1,000 watt car amplifier, because it says 1,000 watts:

http://www.amazon.com/gp/aw/d/B000E432TI

Caveat Emptor.

 

Really, well lets take a look at this beauty, H'mmm 16 1 star feedback on it on Amazon, that's not good, but hey let's see for ourselves....

Hell, I can see why you like this, and you would probably be proud to tell your customers, or friends, it's a true 1000 watts output!
However, ...This is a 2 channel 50 WATT RMS amplifier
It has .04 THD and has a built in crossover.
It how ever DOES NOT have anywhere near 1000WATTS.
Took me all of 2 minutes to read spec sheets, I know what I am looking for, your still not seeing it!!

The last quote is typical of Amplifiers in the C³ Class, Cheap China Crap!

Or were you being "Sarcastic" again?

 

Yes, I was being sarcastic again. Didn't you see where I wrote "caveat emptor"?

But it has "1,000 watt" plastered right on the amp, in big letters. So it must be really loud!