Buying a sound meter

Ika

Lifer
Mar 22, 2006
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what do you do for work, and why do you need to measure sound in dB rather than subjectively?
 

fbrdphreak

Lifer
Apr 17, 2004
17,555
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http://laptoplogic.com/

For measuring laptop noise (fans, HDD, etc) and to compare results between hard drives in the same notebook chassis.

Subjectively is okay, but we're always looking to expand in new and better ways. This is one of them
 

luckysnafu

Senior member
Jul 11, 2003
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That is a cheap sound level meter, probably a type 3. You should look for at least a type 2 sound level meter for good measurements and make sure that the microphone is good as well. Also make sure to buy a calibrator.

Aflac - it is NOT dBs, it is dB
 

Ika

Lifer
Mar 22, 2006
14,264
3
81
Originally posted by: fbrdphreak
http://laptoplogic.com/

For measuring laptop noise (fans, HDD, etc) and to compare results between hard drives in the same notebook chassis.

Subjectively is okay, but we're always looking to expand in new and better ways. This is one of them

I see. I can't give you any input about the actual sound meter, since I've never worked with one, but if you're going to include numbers, make sure to say something about how it sounds - i'd rather have loud and unobtrusive than quiet and whiny.

BTW, nice site.

EDIT:

Originally posted by: luckysnafu
That is a cheap sound level meter, probably a type 3. You should look for at least a type 2 sound level meter for good measurements and make sure that the microphone is good as well. Also make sure to buy a calibrator.

Aflac - it is NOT dBs, it is dB

I know its dB; I meant to say decibelS, plural. Wasn't quite sure how that worked.
 

fbrdphreak

Lifer
Apr 17, 2004
17,555
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Originally posted by: luckysnafu
That is a cheap sound level meter, probably a type 3. You should look for at least a type 2 sound level meter for good measurements and make sure that the microphone is good as well. Also make sure to buy a calibrator.

Aflac - it is NOT dBs, it is dB
Will a type 3 be good enough to measure low sound range (probably no greater than 20dB if I had to guess) and differentiate with only a few dB difference in different rigs?
 

fbrdphreak

Lifer
Apr 17, 2004
17,555
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Originally posted by: Aflac
Originally posted by: fbrdphreak
http://laptoplogic.com/

For measuring laptop noise (fans, HDD, etc) and to compare results between hard drives in the same notebook chassis.

Subjectively is okay, but we're always looking to expand in new and better ways. This is one of them

I see. I can't give you any input about the actual sound meter, since I've never worked with one, but if you're going to include numbers, make sure to say something about how it sounds - i'd rather have loud and unobtrusive than quiet and whiny.

BTW, nice site.
We're definitely still going to describe it qualitatively, but a numerical comparison has its value also.
 

luckysnafu

Senior member
Jul 11, 2003
546
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71
A cheap meter will work in your case then. Just make sure that when measuring you measure the background noise and compare it to the noise from the fans. If the noise level of the fan is not much higher than the background the actual noise level is lower than what you think it is. For example, if the BG is 40 dbA and the fan level you measure is 45 dBA then the actual level of the fan is somewhere around 42 dBA. You cannot get accurate measurements unless the noise from the fan is high enough above the BG (at least 10 dB).
 

fbrdphreak

Lifer
Apr 17, 2004
17,555
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Originally posted by: luckysnafu
A cheap meter will work in your case then. Just make sure that when measuring you measure the background noise and compare it to the noise from the fans. If the noise level of the fan is not much higher than the background the actual noise level is lower than what you think it is. For example, if the BG is 40 dbA and the fan level you measure is 45 dBA then the actual level of the fan is somewhere around 42 dBA. You cannot get accurate measurements unless the noise from the fan is high enough above the BG (at least 10 dB).
Yeah that's what I'm worried about, how good it will do for a relatively informal setup while maintaining reasonable accuracy. One thing I noticed is this one starts at 40dB, is that really going to be low enough sensitivity? This isn't going to be done in a super quiet lab or anything, more just the best we can shut out as much as BG noise as possible, but it would suck to buy this and be able to get reliable, repeatable, differentiated readings between systems.
 

luckysnafu

Senior member
Jul 11, 2003
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Originally posted by: fbrdphreak
Will a type 3 be good enough to measure low sound range (probably no greater than 20dB if I had to guess) and differentiate with only a few dB difference in different rigs?

Are you talking about 20 dB as the lowest measurement or a range of 20 dB? The one you linked above only goes down to 40 dB but has a range from 40 to 130 (90 dB range). If you don't need to measure below 40 than that one should work fine.
 

fbrdphreak

Lifer
Apr 17, 2004
17,555
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Well that's my concern. I would imagine the greatest range would be +20dB, but what is the average background noise? If the machine makes 10dB noise over a 20dB background noise, then this one won't be able to register that, correct?
 

fbrdphreak

Lifer
Apr 17, 2004
17,555
1
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Thanks, as I'm reading more it looks like that 40dB shouldn't be a problem. The model above this one from the same company has 1.5dB accuracy and is a Type 2 meter, but is twice as much. We're not so concerned about accurately portraying the sound level relative to others' readings, but instead comparing between our own. So if all of our measurements are made using the same meter, and comparing noise levels above BG, do we need better than 2dB accuracy or will the results be repeatable and comparable?

EDIT It appears all the models below about $200 do not have built-in calibration. Is it worth getting a model with built-in calibration? These also tend to be the Level 2 models. Just not sure how worth it these will be over the $75 one