Uh.... squared*squared = "to the 4th power", /= "cubed".
"Cubed" means to the THIRD power.
But then, it isn't even really "squared*squared", as you are multiplying different components by themselves and then multiplying the results -- not the same as multplying a component by itself 4 times.
True that. I once had to quit a job (along with accrued vacation) when ordered by a management suit to lie to a customer (the project goal was to do something that was impossible, and everyone with even a clue of tech understanding knew it -- but when the customer wanted to know how it was progressing I was supposed to pretend it was going just wonderfully and not mention the small problem of the task being un-doable.
2.83V RMS into an ideal 8ohm load = 1watt of power. That's why they use such a cumbersome number. That way you can more or less directly compare it to drivers rated in dB/watt.
I know as engineers we like to work with multiples of 10 (especially when working with logs) but sometimes you just have to dust off the old slide rule.
Whether I'm designing an amplifier or a speaker system and crossover, I'm working primarily with voltage calculations. Maybe some do it differently. Specifications that use volts instead of watts work better for me. I'll convert a specification rated in watts to volts as a first step anyway.
Nobody ever taught me that, but that is how I have always understood it. Everyone I have known that works with audio (except marketing and sales) seems to have clearly understood this.
A book that provides a lot of clarity on power and SPL is an old Howard Sams book "Sound System Installers Handbook." I bought it new in 1974 (for $4.95!) and still have it handy. While it may talk about obsolete equipment, the equations haven't changed since then. And it even tells you how to design a speaker cabinet in the days before Theile-Small parameters. It works because I did it, many decades ago. It's so easy, a caveman could do it. 😀
Me too, since I often know what the power supply rails will be before I start. Or I figure backward to get the rails if I know how much voltage I want on the output. The power rating doesn't really concern me, it's how much headroom the system has they worries me.
I know what the 2.83V is but why not just say 1W? Since that is what it's inferring.
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Because as I already mentioned, impedance is nominal (look at a typical impedance curve for a speaker driver). When designing amplifiers, the engineer targets voltage. When designing speaker systems and actually doing the math, dealing with real world and not nominal impedances, the voltage specifications are far more useful.
If you've always used plug and play software to design speaker systems, this nuance might escape you. Design a speaker system, crossover and all, with an engineering calculator, pencil and paper, using datasheet graphs, and you will see.
I've quit jobs where I have been instructed to lie.
My last boss knew I would not lie and would try to coach me in how not to tell the truth.
Something about gaining the whole world and losing your soul comes to mind.
> we should ditch the Horsepower engine rating
I believe most of Europe already has. Engines are rated in PS (Pferdestärke, horse-strength in German) or now KW.
Jimmy Watt's "horsepower" is based on horse work but was very specific.
He was selling steam engines to replace horse powered water pumps, typically in deep wet mines. He looked at typical pump-work and its horses, and eventually defined a figure of 33,000 ft-lbf/min. A horse can do this much work, or some more, for a short period. But mine-pumping is an on-going chore, and an average horse will not do this much dor hours at a time. A huge Belgian could do more, some ponies do less, underfed horses do worse; horse operators of the time *knew* about how much to allow for different horses.
So if a pump was now working with "three average horses" he could confidently quote his 3HP engine. If the horses were reported to be big or small, he'd adjust his recommendation to 5HP or 2HP.
Metric PS uses round-metric mass and amounts to 98.6% of a Watt (Imperial) HP. Close enough for any practical use.
1972 the kW was made the EEC official power rating. This is so nonsensical that HP/PS is still used as supplemental data.
There are tons of side-meanings. The French had their own, which gave the 2CV its name. They also had the poncelet, a large horse power. "Steam horsepower" was used to rate boilers, assuming some typical steam engine which was out of date before we stopped using steam horsepower.
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"RMS" in audio watts may be a poor way to signify "sine". We "could" test audio gear with Square, or multi-tone, or narrow spikes. But in early days we could not conveniently generate complex signals. Square is too extreme for most speech/music audio. That really leaves Sine, such as L-C oscillator or the later H-P 200 and also BFO oscillators.
There are three obvious metrics of a Sine. Peak (or p-p), Average, or RMS. But metering developed to check if incandescent lamps would be happy. Lamps respond mostly to the RMS of their power wave. While most meters were Average, and a few were Peak, nearly always the scale was numbered on the RMS of a Sine. And said so on the dial. If all your waves are near-Sine, the conversion is trivial 0.9-1.0-1.414.
So you read "RMS Volts" on the meter, figure for your load, and get Watts. Including the "RMS" is pointless, but harmless, except when it wastes global brain-power arguing about it.
I believe most of Europe already has. Engines are rated in PS (Pferdestärke, horse-strength in German) or now KW.
Jimmy Watt's "horsepower" is based on horse work but was very specific.
He was selling steam engines to replace horse powered water pumps, typically in deep wet mines. He looked at typical pump-work and its horses, and eventually defined a figure of 33,000 ft-lbf/min. A horse can do this much work, or some more, for a short period. But mine-pumping is an on-going chore, and an average horse will not do this much dor hours at a time. A huge Belgian could do more, some ponies do less, underfed horses do worse; horse operators of the time *knew* about how much to allow for different horses.
So if a pump was now working with "three average horses" he could confidently quote his 3HP engine. If the horses were reported to be big or small, he'd adjust his recommendation to 5HP or 2HP.
Metric PS uses round-metric mass and amounts to 98.6% of a Watt (Imperial) HP. Close enough for any practical use.
1972 the kW was made the EEC official power rating. This is so nonsensical that HP/PS is still used as supplemental data.
There are tons of side-meanings. The French had their own, which gave the 2CV its name. They also had the poncelet, a large horse power. "Steam horsepower" was used to rate boilers, assuming some typical steam engine which was out of date before we stopped using steam horsepower.
---------------------
"RMS" in audio watts may be a poor way to signify "sine". We "could" test audio gear with Square, or multi-tone, or narrow spikes. But in early days we could not conveniently generate complex signals. Square is too extreme for most speech/music audio. That really leaves Sine, such as L-C oscillator or the later H-P 200 and also BFO oscillators.
There are three obvious metrics of a Sine. Peak (or p-p), Average, or RMS. But metering developed to check if incandescent lamps would be happy. Lamps respond mostly to the RMS of their power wave. While most meters were Average, and a few were Peak, nearly always the scale was numbered on the RMS of a Sine. And said so on the dial. If all your waves are near-Sine, the conversion is trivial 0.9-1.0-1.414.
So you read "RMS Volts" on the meter, figure for your load, and get Watts. Including the "RMS" is pointless, but harmless, except when it wastes global brain-power arguing about it.
Ah, I did wonder what happened there 😕 The thing is, my primary reason for the new definition WWW or WTW (which I quite like too, although some may think the T is for tweeter) is the falsehood of the fullrange driver, so, wideband is the new truth, sorry 😱
People are in love with current euphemisms or terminology until they go out of fashion. Then they object to them. You can never catch up.
Wideband to Flappydriver?
Wideband to Freeair?
I just want a configuration called WTF then I'll be satisfied.
Wideband to Freeair?
I just want a configuration called WTF then I'll be satisfied.
The (kilo)Watt is actually the only way to denote power which makes sense these days and is the measure of power in the almost universally adopted SI system, only the USA, Burma and Liberia are holding out and still use silly measurements. However in the case of the two latter countries war and internal strife have stopped them from adopting SI officially, it is in wide use inofficially.
All the other hp, bhp, tax hp, steam hp are nonsensical cludges from a time long gone, PS is only quoted to keep pensioners happy who still buy cars.
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