Ambient noise w/0dBA sensitivity SLM

Post by **MikeC** » Mon May 12, 2003 9:13 pm

We discuss the noise levels of PC components routinely here in the SPCR forums, but rarely does anyone talk about their ambient noise levels. I recently had the opportunity to briefly borrow a highly sensitive calibrated B&K "1613" sound level meter from the University of BC's acoustics lab.

It dates back to 1978, weighs over 10 pounds, and is completely analog in design. Yet it has a dynamic range that spans over 130 dB. Its absolutely sensitivity reaches below 0 dBA -- at one point in the midband (~1kHz) we were seeing -4 dBA in the UBC anechoic chamber. Here is a picture, next to an 80mm fan and a hard drive for reference. (warning -- 164Kb picture!)

http://www.silentpcreview.com/files/ima ... &K1613.jpg

I thought it would be interesting to check the ambient noise levels around the house...

My office, which I think of as so quiet: 32 dBA at 5pm with the door and windows closed. With 2 PCs on, at sitting desk postion, 34 dBA -- one of them is in a very noisy stage right now...

My wife's downstairs back office, 8pm, no one else home: 12 dBA. Very very quiet; a dog barking 4 houses away makes the meter jump to 24 dBA! With PC turned on -- hers, based on a Tualatin P3, is the quietest in the house: 16 dBA 1M in front of bezel!!

If people are interested, can do a short piece on ambient sound, acoustics, etc some time soon.

halcyon · Post by **halcyon** » Mon May 12, 2003 10:07 pm

MikeC,

I'm interested. If you do, please do such an article.

I may have missed it, but do you work for (or have you worked for) an acoustic laboratory at the University?

regards,
Halcyon

Post by **MikeC** » Mon May 12, 2003 10:19 pm

I nurtured a working relationship with the Acoustics Dept at UBC over the past year -- part of my search for resources for SPCR. Which is how the UBC fan research project began. That's moving into a higher priority stage this summer. I also work with the Acoustics Dept on PC industry research projects.

Jan Kivar · Post by **Jan Kivar** » Tue May 13, 2003 5:17 am

Now everyone should have a meter like that... As subjective comparisons are... well, subjective.

Jan

aphonos · Post by **aphonos** » Tue May 13, 2003 8:09 am

MikeC wrote:If people are interested, can do a short piece on ambient sound, acoustics, etc some time soon.

I'm interested....oh, wait....that means I'll start spending money to quiet not just my computer, but my house, too?

Will it ever end?

Seriously, it would be an interesting topic to find out more about.

Fastman · Post by **Fastman** » Tue May 13, 2003 8:10 am

I second the motion

I would like to see readings for the refrigerator and heatins system fans (assuming your house has a furnace and ducts).

We'll have to rename the site to ---
silent house review --> can you hear your plants grow?

aphonos · Post by **aphonos** » Tue May 13, 2003 8:13 am

Fastman wrote:can you hear your plants grow?

ROFL

dukla2000 · Post by **dukla2000** » Tue May 13, 2003 12:04 pm

I too would be interested: not sure how many angles you can work on to make sense to the man in the street (e.g. me), but just the 2 numbers you gave (so far

) help form more of the jigsaw:
quiet office daytime - 32dB(A)
quiet office night - 12dB(A)

Explains perfectly why a quiet PC/component/bit that is say 25dB(A) is 'silent' during the day and damn noisy at night.

JimK · Post by **JimK** » Tue May 13, 2003 12:21 pm

MikeC,

I am interested too. How about more of those things like the dog four houses away barking, TV playing normally in the room with the TV, down the hall in the office with the door closed, printer noise when printing and at idle, etc. And your comments about how noisy do you consider the printer vs others you have heard. "My Epson 12345 inkjet is silent at idle but when printing has a typical buzz (not real loud) and measured nn dB(A)."

ez2remember · Post by **ez2remember** » Tue May 13, 2003 2:49 pm

The best thing to test is with something that is common to lots of us, so there can be a real life reference to the dBA levels.

I nominate the Panaflo 80mm L1a at different voltages and your computer at 1 meter away. LOL

Any other nominations?

deci-belle · Post by **deci-belle** » Wed May 14, 2003 10:44 pm

Hi MikeC...glad to see those ancient B&K SLM are being put to good use!

Those were total A-weighted levels that you were measuring, right?

Post by **MikeC** » Wed May 14, 2003 10:49 pm

deci-belle wrote:Hi MikeC...glad to see those ancient B&K SLM are being put to good use!
Those were total A-weighted levels that you were measuring, right?

Yes. Sounds like someone in the know?

Ambient noise w/0dBA sensitivity SLM

Ambient noise w/0dBA sensitivity SLM

Re: Ambient noise w/0dBA sensitivity SLM