At least 25 years ago, the American Federal Trade Commission (FTC) issued rules to the hifi industry which effectively stopped manufacturers from making outrageous claims about audio power output. For example, the FTC set a one-hour pre-condition test at 40% of the amplifier’s power rating as one of the criteria to be met. In other words, if an amplifier was to be rated at 100 watts per channel, it had to be able to withstand testing at 40 watts per channel for an hour, before the full power test was performed.

There were screams of protest from the manufacturers at the time, because it just so happened that the 40% test condition was quite onerous and not far off the maximum power dissipation in an amplifier. It meant that the amplifiers needed good power supplies and generous heatsinks to be able to meet the testing regime. But it was good for consumers. In a very short time, outrageous power output claims disappeared and amplifier designs became much more conservative in their engineering which ultimately resulted in long life and very good performance.

As in so many other aspects of technology, Australia benefited from these overseas regulations but now, since the vast majority of consumer electronic equipment comes from Asia, the benefits of those regulations have disappeared. We now have the ludicrous situation where flea-powered home theatre equipment can come with claims of 5000 watts output, even though its true output is only a few watts per channel. If you want evidence of this, visit one of the consumer electronics stores at your local shopping mall – or have a look at what’s being offered on Ebay.

If you look more closely, you might find that such huge power ratings are accompanied by the letters "PMPO", standing for peak music power output. I am not even going to try to explain or justify these fictitious ratings – they are just nonsense. In fact, if a piece of audio or home theatre equipment makes any reference to "PMPO", it is fair bet that it is junk and if you buy it, it will end up on the council clean-up in a very short time.

The same comments can made about a lot of after-market car equipment. Some of the claims about car speakers defy logic. People are buying car speakers on the basis that a 400W speaker must be better and louder than a 100W speaker and of course the retailers seldom provide any useful guide. In fact, it is entirely possible that a 400W loudspeaker could be less efficient than a competing 100W speaker and therefore will not be as loud for a given power input.

Sadly, it seems as though there is no government consumer advocate who has the skill or willingness to make regulations or guidelines for most consumer electronic equipment. In the absence of guidelines or regulations, consumers are buying a lot of junk and it soon ends up in land-fill.

Unfortunately, even when there are no outrageous power claims, a great deal of low-cost electronic audio equipment sold these days is junk anyway and it seldom lasts for more than a year. For example, in many small audio systems, the CD player packs up after not a lot of use and it is not worth getting it repaired after the warranty has run out.

As an informed reader of SILICON CHIP, you can help less informed people by advising them to stick to the better known brands of equipment which comes with a one or two-year warranty and avoid the stuff that is really cheap.

Leo Simpson