one of these days.....

[otnooishphoo]

decibel

Unit of measure used originally to compare sound intensities and subsequently electrical or electronic power outputs; now also used to compare voltages. A whisper has a sound intensity of 20 dB; 140 dB (a jet aircraft taking off nearby) is the threshold of pain.

An increase of 10 dB is equivalent to a tenfold increase in intensity or power. The decibel scale is used for audibility measurements, as one decibel, representing an increase of about 25%, is about the smallest change the human ear can detect.

The difference in decibels between two levels of intensity (or power) L1 and L2 is 10 log10(L1/L 2); a difference of 1 dB thus corresponds to a level of 100.1, which is about 1.026.

Decibel measurements of noise are often ‘A-weighted’ to take into account the fact that some sound wavelengths are perceived as being particularly loud. Typical sound levels in dBA are: pneumatic drill at 1 m/3 ft, 120 dBA; normal conversation, 70 dBA; and limit of audibility, 10 dBA.




omg i can google

[Tone Deft]

you think we didn't know that already?

[otnooishphoo]

more info then you could possibly want



http://www.phys.unsw.edu.au/jw/dB.html

[Tone Deft]

not really. the wikipedia page is much better.

[otnooishphoo]

not really. the wikipedia page is much better.

http://www.amazon.com/Sound-Reproductio ... 921&sr=1-4

cant find the book i have, i think it's too old
but that one will do, lets all order, amazon will not know whats going on!

[Nogi]

(Power ratio)dB = 10*log(P1/P0) = 10*log(2P0/P0) = 10*log(2) = ~3dB

For P proportional to A^2, where P=Power, A=Amplitude:

(Power ratio)dB = 10*log(P1/P0) = 10*log(A1^2/A0^2) = 2*10*log(A1/A0) = 20*log(2*A0/A0) = 20*log(2) = ~6dB

[Nogi]

(Power ratio)dB = 10*log(P1/P0) = 10*log(2P0/P0) = 10*log(2) = ~3dB

For P proportional to A^2, where P=Power, A=Amplitude:

(Power ratio)dB = 10*log(P1/P0) = 10*log(A1^2/A0^2) = 2*10*log(A1/A0) = 20*log(2*A0/A0) = 20*log(2) = ~6dB

Wow. Way down the page now. Spent too much time looking for typos in my response 'preview'. Anyways.

[Tone Deft]

cut to the chase
http://en.wikipedia.org/wiki/Sound_pressure_level

SPL measurements use the 20*log(gain)

[beats me]

I will gladly trade the trials of my day job for this problem. PM if interested.

Oh class warfare.

[Tone Deft]

huh?

[forge]

xxxx theatre, bloody yobbo's, i'm not surprised.

[Machinesworking]

so there was this great little bar that did shows for years and years. right next door this big building gets built with expensive lofts for sale. people start buying up the lofts next to the loud little bar that was already there. people then complain to the authorities about the loud little bar THAT WAS THERE FIRST. bar has legal battles that are costly, in the end they put up a sound dampening blanket at the front door and can only have quieter acts play.

bull f***ing shit if you ask me.

the world makes me very angry sometimes.

yeah, put people out of their homes so you can use the space one night a week.

homes are more worthwhile than clubs.

They moved in next to the bar, not the other way around. I'm a little touchy about this personally as Broadway/Capital Hill district in Seattle has been gutted of cool record stores, clubs etc. in favor of condos. The yuppies move in to 'cool' neighborhoods for the vibe, and slowly eliminate everything interesting or unique about the neighborhood. Happens over and over again. If there was a legitimate housing shortage in Seattle sure, but there isn't.

Honestly it kind of made me ill to see the Mission turning into hipster/yuppie chic and becoming less hispanic, but that's life.

[smartass303]

Honestly it kind of made me ill to see the Mission turning into hipster/yuppie chic and becoming less hispanic, but that's life.

no,
its gentrification:
http://en.wikipedia.org/wiki/Gentrification

and it sucks,

303

[Jarvisimon]

hmmmm it's all getting a bit nerdy in here.

[Android Bishop]

Honestly it kind of made me ill to see the Mission turning into hipster/yuppie chic and becoming less hispanic, but that's life.

no,
its gentrification:
http://en.wikipedia.org/wiki/Gentrification

and it sucks,

303

explain to me how this sucks worse than living in a GOOD neighborhood that slowly goes to shit as property values decrease and crime goes up?

gentrification: better property values and less crime, oh no!