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.

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.