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[SOLVED] Slope in db/octave

dwsmith

Well-known member
Feb 1, 2012
1,673
On a log plot in the x axis, if I have a slope of -6 db/octave from 100db, what would be the location of the new coordinate?

So the y axis is db and the x axis is in log.

First coordinate is \((10^2, 100)\) then a slope of -6. The second coordinate is \((10^3, ?)\)?

How does one determine the y location?
 

chisigma

Well-known member
Feb 13, 2012
1,704
On a log plot in the x axis, if I have a slope of -6 db/octave from 100db, what would be the location of the new coordinate?

So the y axis is db and the x axis is in log.

First coordinate is \((10^2, 100)\) then a slope of -6. The second coordinate is \((10^3, ?)\)?

How does one determine the y location?
A slope of - 6 dB/octave is equivalent to a slope of -20 dB/decade...

Kind regards

$\chi$ $\sigma$
 

dwsmith

Well-known member
Feb 1, 2012
1,673
A slope of - 6 dB/octave is equivalent to a slope of -20 dB/decade...

Kind regards

$\chi$ $\sigma$
Then \((10^3, 80)\), and if I had a slope of -12 following, it would be \((10^4, 40)\), correct?
 

chisigma

Well-known member
Feb 13, 2012
1,704
Then \((10^3, 80)\), and if I had a slope of -12 following, it would be \((10^4, 40)\), correct?...
Not exactly... $\displaystyle (10^{3}, 80\ \text{dB})$ is correct and -20 dB\decade means $\displaystyle (10^{4}, 60\ \text{dB})$, $\displaystyle (10^{5}, 40\ \text{dB})$, etc...

Kind regards

$\chi$ $\sigma$
 

dwsmith

Well-known member
Feb 1, 2012
1,673
Not exactly... $\displaystyle (10^{3}, 80\ \text{dB})$ is correct and -20 dB\decade means $\displaystyle (10^{4}, 60\ \text{dB})$, $\displaystyle (10^{5}, 40\ \text{dB})$, etc...

Kind regards

$\chi$ $\sigma$
You said -6 is -20 so wouldn't -12 be -40?