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dB per octave spec with a ASD curve
2

dB per octave spec with a ASD curve

dB per octave spec with a ASD curve

(OP)
When someone specs 2dB or -2dB 'per octave' in the context of acceleration spectral density, what does it mean graphically?

Tunalover

RE: dB per octave spec with a ASD curve

If you plot db versus log frequency it should drop at 2 dB per doubling of frequency, in a straight line.

Cheers

Greg Locock

Please see FAQ731-376 for tips on how to make the best use of Eng-Tips.

RE: dB per octave spec with a ASD curve

(OP)
Greg-
dB is a log of a ratio...but what is the ratio in this case?
Tuna

Tunalover

RE: dB per octave spec with a ASD curve

Referenced to your reference value (!). Won't actually make any difference to the slope.

Possible  reference value for an asd would be 1 g^2/Hz but you'd get very negative values. Don't get caught out by the difference between 10 log and 20 log for your dBs.

Cheers

Greg Locock

Please see FAQ731-376 for tips on how to make the best use of Eng-Tips.

RE: dB per octave spec with a ASD curve

(OP)
Thanks Tom Irvine!

Tunalover

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