Mariusz [mr.] wrote:
> ???
> Mi się wydawało, że 6dB = 2x

Mogę się mylić, ale chyba 2x to było 3dB dokładnie.
http://en.wikipedia.org/wiki/Decibel

A change in power ratio by a factor of 10 is a 10 dB change. A change in
power ratio by a factor of two is approximately a 3 dB change. (More
precisely, the factor is 103/10, or 1.9953, about 0.24% different from
exactly 2.) Similarly, an increase of 3 dB implies an increase in voltage
by a factor of approximately ?2, or about 1.41, an increase of 6 dB
corresponds to approximately four times the power and twice the voltage,
and so on. (In exact terms the power ratio is 106/10, or about 3.9811, a
relative error of about 0.5%.)

(ale tam są wzory i można sobie popodstawiać) :)

d.