Yes, it's the Log calculation of attenuation formula.
That's where the dB ratio comes from, by the way.
We are used to just say "-6dB is half voltage, 1/4 the power , 1/2 the turns ratio" just from memory, but this is the original formula.
Just don't like too much how it was written on the image:
POWER(10,-6/20) , although correct, should be clearer if written:
Logarithm (base 10) of (gain/attenuation in dB) divided by 20)
this is for voltage ratio and shows "what we already know" that "-6dB equals half (0.5012 to be more precise) voltage"
by the same token, it shows the same formula but now "^2" which means "squared" and explains the power ratio :
POWER(10,-6/20) ^2 which can be read aloud as:
Logarithm (base 10) of (gain/attenuation in dB) divided by 20) and-then-squared = 0,5011*0,5011=0.2511
which "we already knew" that "-6dB=1/4 the power"
In fact I am quite sure that such formulae can be written in Excel or any other similar spreadsheet.
Thanks lojzek for posting
By the way, the formula in the image also lets you calculate, in a similar way, the inductance "seen"" by a speaker connected to a tap, instead of end to end.
Very clever and useful, although not exactly written in the most user friendly way
I'm quite certain that the way it was originally written, is the way his "Excel" or whatever demands .
That's where the dB ratio comes from, by the way.
We are used to just say "-6dB is half voltage, 1/4 the power , 1/2 the turns ratio" just from memory, but this is the original formula.
Just don't like too much how it was written on the image:
POWER(10,-6/20) , although correct, should be clearer if written:
Logarithm (base 10) of (gain/attenuation in dB) divided by 20)
this is for voltage ratio and shows "what we already know" that "-6dB equals half (0.5012 to be more precise) voltage"
by the same token, it shows the same formula but now "^2" which means "squared" and explains the power ratio :
POWER(10,-6/20) ^2 which can be read aloud as:
Logarithm (base 10) of (gain/attenuation in dB) divided by 20) and-then-squared = 0,5011*0,5011=0.2511
which "we already knew" that "-6dB=1/4 the power"
In fact I am quite sure that such formulae can be written in Excel or any other similar spreadsheet.
Thanks lojzek for posting
By the way, the formula in the image also lets you calculate, in a similar way, the inductance "seen"" by a speaker connected to a tap, instead of end to end.
Very clever and useful, although not exactly written in the most user friendly way
I'm quite certain that the way it was originally written, is the way his "Excel" or whatever demands .
thanks dude
I was never good at mathematics. I should have listened to my teacherYes, it's the Log calculation of attenuation formula.
That's where the dB ratio comes from, by the way.
We are used to just say "-6dB is half voltage, 1/4 the power , 1/2 the turns ratio" just from memory, but this is the original formula.
Just don't like too much how it was written on the image:
POWER(10,-6/20) , although correct, should be clearer if written:
Logarithm (base 10) of (gain/attenuation in dB) divided by 20)
this is for voltage ratio and shows "what we already know" that "-6dB equals half (0.5012 to be more precise) voltage"
by the same token, it shows the same formula but now "^2" which means "squared" and explains the power ratio :
POWER(10,-6/20) ^2 which can be read aloud as:
Logarithm (base 10) of (gain/attenuation in dB) divided by 20) and-then-squared = 0,5011*0,5011=0.2511
which "we already knew" that "-6dB=1/4 the power"
In fact I am quite sure that such formulae can be written in Excel or any other similar spreadsheet.
Thanks lojzek for posting
By the way, the formula in the image also lets you calculate, in a similar way, the inductance "seen"" by a speaker connected to a tap, instead of end to end.
Very clever and useful, although not exactly written in the most user friendly way
I'm quite certain that the way it was originally written, is the way his "Excel" or whatever demands .
thank you too
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