Decibel meters?

Tim

Tim

Checked Out
Staff member
2A Bourbon Hound 2024
2A Bourbon Hound OG
Charter Life Member
Benefactor
Vendor
Multi-Factor Enabled
Joined
Dec 17, 2016
Messages
16,589
Location
A Glass Cage of Emotion
Rating - 100%
85   0   0
Are the smart phone app decibel meters any good?

I shot my F1 9mm can today at an indoor range with a 10.5" SBR. The phone was laying on the bench about 3ft below the muzzle, directly underneath. The decibel meter averaged ~116 over 10 shots.

I was pretty excited about that result until I shot without the can and registered ~121db. That seems awfully low considering there was no muzzle device at all.

so...what's the verdict on phone based meters?





 
Last edited by a moderator:
Completely worthless.

The mic can't pic up the level of dB, and the sampling rate is too slow to catch it even if it could.
 
What's the cheapest entry level real one out there?

I'd love to get my hands on one sometime.
 
I think to get one that meets the mil-spec standard, you're in he $5K-$10K range. Meter and mic are both pricey.

I'm not sure there's even a digital meter out there that meets the standard. Analog is the only option to do it the right way.

You can probably find some that handle suppressed subs OK, but few will handle the unsuppressed full power calibers.

The big issue is the sampling rate. Most options are made to capture continuous sounds, like a jet engine or a concert. They can't catch the peak of the curve for a gunshot, and you end up with a measurement somewhere on the downslope.
 
That's what I figured, thanks.
 
Dang, that pretty much means I'll never have one. Imagine buying a $5,000 meter for a $100 can. :eek:
 
You can find a decent pressure wave meter for under $500. It will not give you peak sound but it will give you the decibel reading to the average human ear. That meter will give you an idea of the pressure level that makes it to your ear drum. Though over 100 db there is a margin of error that requires many tests and an average to find a number reference,. Still again you would need a lab quality meter that will run about 10K.
 
This seems to be a very wiggly measurement to take , as there's no ISO standard to configure the tests....and the configuration is key to meaningful results.
 
JohnFreeman;n30788 said:
This seems to be a very wiggly measurement to take , as there's no ISO standard to configure the tests....and the configuration is key to meaningful results.
Click to expand...

May not be ISO, but MIL-STD-1474D has been the standard to use. I think it may be "E" by now, but I'm not sure what changed.
 
Yeah, it's a tricky measurement to make IF you want to compare it to someone else's measurements made somewhere else. If one is just looking for relative readings, then even the handheld apps are probably useful. Mil Std measurements don't come cheap (nor ISO, for that matter)
 
Last edited by a moderator:
Well another issue with that app is it looks to max out at 130db. Nearly all 5.56 cans will be above 130db and an unsuppressed shot is nearly 170db.

I was was watching a few MAC (military arms channel) videos on YouTube yesterday and he does a decent job of explaining the equipment used and its setup for testing a range of cans.

Ive used the same app pictured above and it probably works fine for voices but I can't imagine the phone microphones are capable of picking up gunshots all that well. When I tested it with my 22 sparrow, it was cool but I didn't trust the numbers.
 
Back in the day audio control made an anolog meter that was used for car audio competitions. It was geared to bass under 100 hertz. They also had a spectrum analyzer that would pick up 20-20k. As far as accuracy goes they were pretty liberal on the high side. I remember 150db on the A/C at 40 hrtz was in the 146 db range on the "newer" term lab sensors.
 
Agree with the 5k - 10k estimate. I'm in the middle of a study looking a noise levels in the OR during total joint replacement - learning a lot working with audiologist and environmental health experts. Cell phone apps are garbage - our noise dosimeters are in the 10k range I think (scared to ask). Interestingly average OR noise 70-80 dB, with peak around 106 per case. Once you hit certain exposure per day it is considered a health hazard.
 
You must log in or register to reply here.
Back
Top Bottom