PMPO Query

Because marketers are only bound by law if the law can catch up with them.

Never confuse that which is written with the truth.

But if you wish to be hopelessly pollyanna-ish, then here's a rationalization: "PMPO" stands, presumably, for "peak music power output". "Music power" is a euphemism for "power that only has to be delivered once in a rare while" - that is, 500W "music power" is only about 50W average power. So, if you can deliver 50W average power, then you can fool yourself into thinking that you can deliver 500W "music power" even though, when the occasional 500W peak comes along, you can't actually deliver it.

Here's another way of thinking about it: what THD is that 500W specced at? If in a given music test signal only 5% of peaks exceed 50W, and if I clip

5% of the peaks (that is to say, I clip everything over 50W), then I might still be under a few percent THD. Suppose those peaks are actually 500W. Then, I can say that I am delivering "500W of music power" at a few percent THD.

The bottom line here is that there are many, many ways to mislead with power specifications.

Peak Music Power Output

Peak Music Power can be almost anything you claim it to be.

Continuous Sine Wave output is/was the industry standard for audio amplifer testing when I was building stuff.

Peter

-- Peter & Rita Forbes snipped-for-privacy@easynet.co.uk Engine pages for preservation info: