Noise Profile Capture of a UMIK-1 (you might want this file) - AVS Forum
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post #1 of 7 Old 12-10-2014, 09:39 AM - Thread Starter
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Noise Profile Capture of a UMIK-1 (you might want this file)

Here is the noise Profile of a UMIK-1.

In order to capture this data I had to use all the noise-blocking resources available to me.

Starting with 8 1cuft corner traps to make a make-shift anechoic chamber, inside my already soundproof theater, at 4am on a winter night.
I stuck my head in there to confirm the SPL. I would say it was 1-4db ish.


Here is the RAW noise profile file I captured, you can use this as a generic sampler for a noise reduction filter (if you ever need one, and want one that is decently well recorded).
https://drive.google.com/file/d/0BwU...ew?usp=sharing

Here is what I recorded amped to 0dbFS.



The only source of noise that the mic "seems" to be detecting is perhaps some sort of distant train perhaps 1-3 miles away. 15-40hz is all that remains after it goes through all the soundproofing.

Here is what it sounds like outside, direct exposure. I had to block all that!
Damn humans! That's only a few cars. I could only imagine how noisy New York or LA would be!!!!! (20 million cars?)
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Last edited by BassThatHz; Yesterday at 06:55 PM.
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post #2 of 7 Old 12-10-2014, 10:02 AM - Thread Starter
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Went for a walk and found the noise source:

50,000lbs rigs/cars + trains, is the primary noise source, freeway 1000's of ft away, reflecting off the mountain; also a few miles of moving water probably rumbles the ground at single digits too. Hard to reach 0db in the bass region.


Last edited by BassThatHz; Yesterday at 06:59 PM.
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post #3 of 7 Old Today, 12:32 AM - Thread Starter
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I keep forgetting that humans can hear down to -9db @ 3-4khz, and 10db to 300-400hz; that requires an amazingly quiet space not typically found in a normal house.



This is the best the UMIK can do: 35db of separation between peak and floor.
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post #4 of 7 Old Today, 02:35 AM
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post #5 of 7 Old Today, 07:31 AM
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Quote:
Originally Posted by BassThatHz View Post
I keep forgetting that humans can hear down to -9db @ 3-4khz, and 10db to 300-400hz; that requires an amazingly quiet space not typically found in a normal house.
And a complete lack of irritating tinnitus drowning everything out in really quiet places?


[/resigned to never hearing silence again] lol
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post #6 of 7 Old Today, 07:27 PM - Thread Starter
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Quote:
Originally Posted by notnyt View Post
I'm fairly certain it can measure a wider range than 35db.
Actually you are right it can do a range of 115-124db at 1khz-20khz, and 80db at 5hz.
I guess I just need to use a slightly louder noise source, like a super tiny firecracker or something.

Doh!

I guess what I really meant to say is that a fancy ACO Pacific mic would have done 5-30db better in the negative direction, and theoretically up to 45db better in the positive pressure direction, simultaneously.
So it would have done at least 50db floor to peak, given the exact SAME conditions, it's just that much better...

I wonder what mic Guinness records used when they measured -9.4dbA at Orfield Labs?
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post #7 of 7 Old Today, 07:33 PM - Thread Starter
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If you started in a room that was 30-40db and had it at gain-0, then it would only be 90-100db. So the extra range that it has, is only ever seen with super-loud events inside anechoic-like circumstances.
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