Because audio is wildly dynamic, discussions about power and signal
levels can get confusing. Audio program material is virtually never
close to approaching sinusoidal. The practical limitations include the
"beefiness" of the power supply, and voltage and current capabilities of
the output devices, and dissipation. In addition, audio power amps are
constant voltage devices, with output impedances generally below 0.1
ohms. If their power supply is sufficiently beefy, the power they can
provide is inversely proportional to the load impedance. Not only that,
the load impedance of real loudspeakers is a highly variable complex
function, including various electrical and mechanical resonances in both
the transducers and their enclosure. Loudspeaker impedance is defined as
the minimum value of the magnitude of the impedance in the midrange; in
multii-way loudspeakers, there's also a passive crossover network that
distributes power by frequency range between two or more drivers, and
adjusts the relative levels to each frequency range depending on the
sensitivity of the transducer for that range.
So-called RMS power ratings for power amps are for a constant sine wave;
mfrs of amps with less robust power supplies often use "music power,"
which the based on the RMS value of a sine wave corresponding to the
audio peaks in program material. This is not an unreasonable cheat,
simply because all audio is so dynamically variable.
73, Jim K9YC
On 1/20/2020 12:15 PM, Fuqua, William wrote:
There is an article about RMS Power in Electronic Design. Naturally it has
to do with High Fidelity stuff.
What they are referring to is Continuous Average Power but calling it RMS Power.
https://www.electronicdesign.com/power-management/article/21120866/whats-the-difference-between-rms-and-peak-watts?utm_source=EG+ED+Analog+%26+Power+Source&utm_medium=email&utm_campaign=CPS200117061&o_eid=7152E2758401H1B&rdx.ident%5Bpull%5D=omeda%7C7152E2758401H1B&oly_enc_id=7152E2758401H1B
I was going refer to author as an HF nut but that would be confusing. High
Frequency RF or High Fidelity? Hi Hi
73
Bill WA4LAV
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