A horn throat distortion question, and eficiency Vs dynamics?

[DualTriode]

Hello,

I just searched the WWW looking for information on horn distortion and came across this thread. I am surprised with the misunderstanding of dB’s.

Even if this is from years ago here goes.

dB=20*Log10()

If the power input to the speaker is X 1:
dB=20*Log10(1) = 0dB change

If the power input to the speaker X 2:
dB=20*Log10(2) = 6.02dB change

If the power input to the speaker is X 4:
dB=20*Log10(4) = 12.04dB change

If the power input to the speaker is X 8:
dB=20*Log10(8) = 18.06dB change

If the power input to the speaker is X 16:
dB=20*Log10(16) = 24.08dB change

For each doubling of the power input there is a 6dB increase in the output. I do not remember where this 3dB delta misconception came from.

[grumpy]

So, 20log(Vout/Vin) works, but it’s 10log(Pout/Pin).

...has to do with power being a function of V squared.


http://www.arrl.org/files/file/Instructor%20resources/A%20Tutorial%20on%20the%20Dec-N0AX.pdf

[Robh3606]

There is no misconception we are talking power not volts. Take a look at table in the reference Grump posted. With speakers not worried about voltages more about power into the load/speaker

Rob