Nope. Your formula is correct for sound energy. For sound pressure, you need to square the two pressure terms you’re comparing, so you end up with 20 log(2), which equals 6 dB. An increase of 20 dB represents a tenfold increase in sound pressure.
As for the OP, I would seriously question the accuracy of your measuring equipment - as you rightly noted, a maxed out audio system does not produce levels of 85 dB.
sure, there are any number of tone generator apps for Android that’ll put out pink noise.
No. A-weighting was originally intended for characterizing background noise levels. It doesn’t really apply to really loud sounds since human hearing is not linear with volume (see Fletcher-Munson curves.) For something at loud SPLs like a cranked-up car system or concert, no weighting should be used.
see, the thing about A-weighting is it is supposed to be used at low to moderate SPL levels (up to about 85-90 dB) to try to characterize the specific frequency ranges that people can be exposed to which can cause the most apparent hearing damage. OSHA applies to job environments like factories or airport workers because they tend to be exposed to noisy shit for 6-10 hours a day, and can’t necessarily leave if they feel like it. OSHA standards do not apply to people going to a concert or cranking up their car stereo because those are not occupations. If the concert is too loud, you can leave. if your car stereo is too loud, turn the damn thing down.
I get what you’re trying to say, but the problem is that music is a random, non-steady-state signal. To get any useful SPL measurements while playing music, you need a looooooooonnnnng averaging time, and I don’t think many low-cost SPL meters have that kind of averaging window. You could use one of the PC-based real-time-analyzers like TrueRTA, a decent microphone, and a calibrator. Then you could specify a large number of averages to get the avg SPL, and use peak hold to see the peaks.
well, I’ve never looked into whether SPL meters use free-field or pressure microphones (I assume the latter) but it’s not about the direction it’s pointed, and the weighting is irrelevant. It’s about getting a spatial average of the SPL in a particular area. If I have to take a measurement in a car and I’m stuck with a single microphone, I’ll generally point it upward and move it in a horizontal circle about 10" diameter at the approximate position of the driver’s head for a reasonable number of averages.
I stand corrected. Thanks.
I’m sorry, but I’m forced to use “C” weighting. Sound level meters usually only offer A/C weighting button. So, the closest I can get to no weighting is “C”, because that is flat for most of the time.
Yes, but how can I actually determine how loud I can listen to music that loud for. That’s the question here. Should I take the “unweighted” (it really WON’T be unweighted, but close) sound level and compare it to the OSHA regulations, the NIOSH regulations? How can I actually know, how long I am aloud to be exposed to music that loud. And, mine averages the sound level over 1 second, so that’s pretty short…
So are you trying to tell me: use “A” weighting for background/environmental noise measurements or for machines (with the intention to refer to OSHA) and use “C” weighting for music, and loud SPL’s above 85 dBA, or when measuring performance of things in order to get a fair, mostly unweighted value? (Sorry if I’m frustrating you; I’m just trying to understand how to use my sound level meter effectively).
you’re trying to do some things which your sound level meter wasn’t designed to do.
What things? And how is it not designed to do those things?