What is Audio Watts RMS to PMPO Calculation sample
PMPO WATTS:
Most Audio you see have a label "watts PMPO" on product packaging. PMPO is also called it Peak Music Power Output. Sometimes misused in advertising as Peak momentary performance output, is a much more dubious figure of merit, of interest more to advertising copy-writers than to consumers.
So what does it mean?
The term PMPO has never been defined in any standard but it is often taken to be the sum of some sort of peak power for each amplifier in a system. Different manufacturers use different definitions, so that the ratio of PMPO to continuous power output varies widely; it is not possible to convert from one to the other. Most amplifiers can sustain their PMPO for only a very short time, if at all; loudspeakers are not designed to withstand their stated PMPO for anything but a momentary peak without serious damage.
source:en.wikipedia.org/wiki/Audio_power
RMS WATTS :
Root Mean Square. RMS is the process used to determine the average power output of the speakers over a long period of time.
RMS is derived from an equation which produces the most mathematically accurate measure of a speaker's power output. The RMS value is often seen listed as "watts RMS" on product packaging sometimes not.
Continuous average sine wave power ratings are a staple of performance specifications for audio amplifiers and, sometimes, loudspeakers.
read more: en.wikipedia.org/wiki/Root_mean_square
I Try to find what is a best meaning on net or what does it work in audio amplifier, But I can"t find standard calculation of this. So many people told was "IGNORE label PMPO Watts" I read...
The PMPO rating has no standardized definition.
The PMPO is the max output of milliseconds
The PMPO cannot be determined by looking at a different watt rating and multiplying it.
The PMPO Have no Standard calculation from RMS Watts
On May 3, 1974, the Federal Trade Commission (FTC) instated its Amplifier Rule to combat the unrealistic power claims made by many hi-fi amplifier manufacturers. This rule prescribes continuous power measurements performed with sine wave signals for advertising and specifications of amplifiers sold in the US.
To determine RMS value, three mathematical operations are carried out on the function representing the AC waveform:
(1) The square of the waveform function (usually a sine wave) is determined.
(2) The function resulting from step (1) is averaged over time.
(3) The square root of the function resulting from step (2) is found.
The alternative to RMS is PMPO(peak momentary power output) which represents peak output measured in microseconds rather than over a long period of time.
In a circuit whose impedance consists of a pure resistance, the RMS value of an AC wave is often called the effective value or DC-equivalent value.
For example, if an AC source of 100 volts rms is connected across a resistor, and the resulting current causes 50 watts of heat to be dissipated by the resistor, then 50 watts of heat will also be dissipated if a 100-volt DC source is connected to the resistor.
For a sine wave, the rms value is 0.707 times the peak value, or 0.354 times the peak-to-peak value. Household utility voltages are expressed in rms terms.? Aso-called "117-volt" AC circuit carries about 165 volts peak (pk), or 330 volts peak-to-peak (pk-pk).
The alternative to PMPO is RMS (Root Mean Square), which is an accurate mathematical representation of a speaker's power output, measured over time rather than a few microseconds.
By putting “1000 watts” on a box, the manufacturer is making the claim that the product can put out 1000 watts of power. But there is no standard for measuring PMPO, and amps that make PMPO claims may only be able to hit that peak for one cycle.
The industry standard is Watts RMS, and that’s the only thing you should be looking at when buying audio equipment.
How about in my Experience in my Unboxing of amplifier?
Ok that's it, For me, I give basic Idea related to my content. I give an example. I posted of audio power amplifier have label of 2000W PMPO but after unboxing, there are 2 CHIPS have rated max output of 35 Watts each channel (4Ch)
This Amplifier above have a total of 140 watts RMS, Each Channel is 30W RMS at 4 Channel on PDF..
because of two IC inside name TDA7377..
LETS CHECK TDA7377 PDF SCREENSHOT of Chips inside of amplifier on Video..
So i have a formula but not standard, It is only Ideas as my Experience of Unboxing....
According to printed on amplifier is Max power of total 2000W I will divided to 4 output = 500W PMPO.
On a board Chips PDF bridge have max output RMS into 4 OHm at 14.4V =35W RMS per bridge and 30W RMS at 12V channel.
1 channel bridge is 30W RMS.
1 channel bridge is 500W PMPO
4 Channel output is now 2000w PMPO
4 Channel output is now 120W RMS
2000 divided to 120 = 16.67Watts PMPO
RMS to PMPO Calculation sample
(1 Watts RMS = 10-20 Watts PMPO)
Computation is not less than 10W and not more than 20W
That means the result computation on video above is 1W RMS to PMPO of TDA7377 is 16.67W
Four Channel of amplifier above is a total output of 120W RMS multiply by 16.67W PMPO is equal to 2000W.
"The true output of this 2000W is only 120Watts can load a 250W Speaker"
Believe me or not, But my calculation is correct base on PDF chips and a label of amplifier...
My basic explanation here because there is NO exact calculation of RMS to PMPO But I give a rated a 1WATT RMS is equal to 10-20 Watts PMPO as reference to get the true rated power output of some amplifier have a BIG watts printed on label ^_^
Please Watch Video How to get Actual Watts Rated of this 200W 4channel Chips
Another Example,
The Figure of Amplifier above is Rated at 100Watts PMPO per channel when I dismantle it I see clearly a Chips amp is TDA7266SA. Lets compute it if this came result as 1Watts rms is equal to 10 -20 Watts PMPO.
100Wx2 200W PMPO
TDA7266sa is 7Wx2 = 14W rms
200w PMPO divided to 14W RMS = 14.286W PMPO
"The True Output of 100W PMPO is 7watts per channel can load 30-50Watts speaker"
The calculation is exact again to 1 Watts RMS = 10-20 Watts PMPO i said above
In fact, most amplifiers labeled as "1000 watts PMPO" have a true Chips on board is output of 10-20 watts or less.
But Hey..Dont be angry to the manufacturer of amplifier Rated 1000W or more in label..
But The Manufacturer uses wattage calculation in Printed label is PMPO(Peak Music Power Output.)
That's why you will notice "A high watts advertisement not same on the chips inside.
Because In standard Durability of amplifier with speaker system,It must be 3 times higher the speaker watts to the output of amplifier to not make it heat the chips and not burning the speaker
Most Amplifier I experience is give better sound on Car Audio experience. Just imagine if the gadget have 30+30Watts RMS Chips (1000W PMPO) can Drive a Total of 400W speakers.
Example: 1 Woofer 200W, 1 Midrange 80W, 1 Tweeter 80W try it... You will see give a loud sound..
This is only Reference it you Buying product when indicates have high watts on printed label on amplifier,
I hope it helps.....
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