freq range, 50hz-20khz at + -3db please explain


My loudpeakers are quoted as 50hz - 20khz ( + - 3db ) and 40 hz - 20 khz ( + - 6db ) Could someone explain what the plus and minus 3 and 6 db means.
andrewrona

Showing 1 response by fatparrot

Duffydawg, there appears to be some confusion in your dB facts.

A 3 dB INCREASE is a DOUBLING of ACOUSTIC POWER [dBw or decibel watts]. A 6dB increase would be a quadrupling of dBw. A 9 dB increase would be an 8 fold increase of dBw.

Now, if we're talking about VOLTAGE, not power [dBv or dB voltage] it takes a 6 dB increase to double the voltage, or a 12 dB increase to quadruple the dBv.

People with good hearing should be able to detect a 1-2 dBw increase in the mid frequencies [not the ultra highs or ultra lows]

The dB readings are a logarithmic progression; someone will provide the formula, no doubt.