Speaker Specifications

Hello ravi00bkp

Originally loudspeakers were rated at a Sine Wave input, at an audio frequency, generally 100 Hz for a Bass Speaker, 5kHz for a mid-range Speaker, and 10kHz for a tweeter.

In those days, 1950'2 and early 1960's, most makers were reasonably honest with the power ratings.

Later, with development of very high field strength permanent magnets, using rare earth "doped" technology, the power input was able to be greatly increased, but required a voice-coil which was much longer on the coil support at the rear of the speaker cone, to enable the voice coil to be fully driven at larger power level without the coil moving fully out of the high intensity magnetic field..

Then came the advertising gimmicks, of rating loudspeakers with PMPO (Peak Music Power Output) ratings, which really looked good because the figures were large, and the gullible public, who liked to be able to boast of their very powerful stereo systems, played the "numbers game" - "My stereo puts out more power than yours".

Thus most speakers today, are rated PMPO, because the numbers are generally some 10x to 20x times larger than the same loudspeakers when rated at a Sine Wave specification.

Example of a typical modern speaker in a stereo consumer electronics device, would be: Continuous Sine wave output of 5 Watts at a particular frequency as tested, and a PMPO of 200 Watts at any frequency or frequencies.

So you can see that the PMPO speaker rating is just a sales gimmick.

Kind Regards....

some of my friends told me that the specification is a 10 th power of the actual power(electrical)

becoz we here sound as log .is it correct?

Hello again ravi00bkp

No, the whole thing about PMPO ratings is an advertising gimmick, because large numbers used in output ratings impress those who do not understand, and think they get more sound for their money.

We do perceive sound on a logarithmic basis, that is how our hearing ability was designed, and that enables us to hear very small sounds, without having our eardrums burst from the sound of a thunderclap.

Kind Regards....