Why? If I have 1V and 1A running through a resistor, 1W will dissipate no matter how long it stays that way. P=J/s so even if the time is tiny and the total energy is tiny, the wattage is still the same. Am I missing something here?
Since the impedance of the speaker is varying with frequency, a graph showing output avarage continous wattage vs. impedance would give pretty correct values? Can it get more honest than that?
I Guess that it wasnt enough , a sine , even distorted , has less area
than a square signal , hence , PMPO , pulse mode or pure marketing
power output , will enhance 5W amplifiers or so to a 80W rating...
You can set all the good standards you want (they do exist) but it will never stop the salesmen from lying. That the way of business.
But just because salesmen lie, that does not mean you have to abandon or ignore the standards. Most of the standards are very useful and well thought out. Most salesmen lie. All the hand wringing in the world will not change either fact.
But just because salesmen lie, that does not mean you have to abandon or ignore the standards. Most of the standards are very useful and well thought out. Most salesmen lie. All the hand wringing in the world will not change either fact.
Yes we can. It may be misleading (perhaps deliberately) but it is certainly true. If the sine wave was very low in frequency when compared with typical thermal time constants of the load then we would need to ensure that the load could handle 16W without damage.forr said:
Can we assume that when quoting peak or instantaneous powers that the unit should be Wpk?
In the above post, 11.3Vpk giving rise to 16Wpk.
Is that the correct way to describe?
Is that a way to avoid ambiguity?
In the above post, 11.3Vpk giving rise to 16Wpk.
Is that the correct way to describe?
Is that a way to avoid ambiguity?
The unit of power is watts - W, whatever power is being discussed. I think I would call it peak instantaneous power, as that is unambiguous. The pk is not part of the unit, but a helpful descriptor.
Strictly speaking, 11.3Vpk is incorrect. It should be Vpk=11.3 V. Vpk is the name of a particular voltage. V is the unit in which it is measured. So we could say Ppk=16 W.
Strictly speaking, 11.3Vpk is incorrect. It should be Vpk=11.3 V. Vpk is the name of a particular voltage. V is the unit in which it is measured. So we could say Ppk=16 W.
One channel driven, both channels driven, continuous or 3 cycle tone burst, 1 kHz or over the whole audio band, too much wiggle room for cheating. If you really want to get clever you can apply a tolerance to the voltage measurement so you have a nominal and a minus band, then spec everything at the nominal. Real units will all operate at the minus limit of voltage, and thus far fewer watts because of the squared term. You just have to use your imagination in this business. 😱
I quoted your post because I wanted to refer to the formula that you recommended to use after reading the voltage on the speaker. I'm talking about mathematical formula P = V ^ 2 / R (formula where do you refer, somewhat indirectly).
In the formula above, some manufacturers of professional amplifiers employ the notion of peak to peak voltage instead of rms voltage. For example, I have a stereo FFH-886 manufactured by LG. LG says it has 2 x 233Wrms. I measured the output power and it is 2x80Wrms. It is based amplifier STK 412-040.
And there are many such examples.
Don,
say what's in your head instead of quoting a whole post without referring to the pertinent section/part.
- Status
- Not open for further replies.