I have been testing my new Leshiy 2 with a quality calibrated noise meter but I am seeing a large variance between other other posters. This led me to do research on the internet of how to setup a noise test. Couldn't find a standard setup for airguns but did learn that I had made some mistakes about being to close to reflective surfaces. I then reviewed some of Steve's AEAC reviews. It looks like he places his noise meter at between 12 to 15 feet from the muzzle. I tried a setup today that put my sound meter 12 feet from the muzzle and 4 feet to the right of the barrel center line. My values with my Skyhawk-DonnyFL Tanto combination versus his Skyhawk-DonnyFL Tanto combination test are close. My question - Is there a standard on placement of the airgun under test and the noise meter? I understand how to use a noise meter and have used them for years with audio equipment setup. What I don't know is the physical setup for a valid airgun noise test.
Standard setup for airgun noise testing?
- Thread starter fderry
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My standard setup is 3 feet from the muzzle or my iPhone with my arm stick out. As long as you keep your set identical then your data will have a reference point and therefore valid and useful.
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I have a bud shoot it 20-25 yards away from me and pay attention to hear other than the bumble bee sounding pellet zip by. Then I know what the neighbors can hear. Tried at 50 yards and sounds like an army movie only pellets zipping by.
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Eaglehorn
I have read this blog before. He is very knowledgeable and his focus is on suppressor design and testing. He is using special test equipment and looking at a lot more than just simple noise levels. I got hoked on his blog awhile back because he was also looking at frequency distribution and how suppressors are designed. Great information but unfortunately his test philosophy and setup doesn't translate to simple noise meter testing. Thank you for reminding me of his blog.
I have read this blog before. He is very knowledgeable and his focus is on suppressor design and testing. He is using special test equipment and looking at a lot more than just simple noise levels. I got hoked on his blog awhile back because he was also looking at frequency distribution and how suppressors are designed. Great information but unfortunately his test philosophy and setup doesn't translate to simple noise meter testing. Thank you for reminding me of his blog.
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As you may know, the testing equipment you use can render a range of results quite different from what others get because of the equipment. Are you using a "sound level meter", a true dosimeter such as the 3M Quest NoisePro, or a phone with an app? You mentioned reflective surfaces- are all your samples collected in the same space, conditions, and environment? How do those compare to others whose results you are comparing to?
I would not be too concerned about what results others are getting nor what constitutes a "valid" test. I would be more concerned about the differences YOU are getting among your different configurations. Is quieter quiet enough for your needs?
I would not be too concerned about what results others are getting nor what constitutes a "valid" test. I would be more concerned about the differences YOU are getting among your different configurations. Is quieter quiet enough for your needs?
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It seems the consensus so far is it doesn't matter as long as I can live with the sound my air rifle is putting out. I like Odoyle's analogy. I live on 5 acres in a semi-rural area. I can legally shot a 50 BMG on my property if I prove to the Sheriff, who will eventually show up, that I have a safe back stop. So I'm not overly concerned with the noise of my airguns (but my wife and dog are!). The reason I am asking this question is I was PM'ed a question about my posted noise data on my Leahsiy 2. As I looked at my test methodology I realized I needed to be more precise if I was going to provide meaningful information to another forum member. This is why I'm trying to discover if there is a standard test setup that is agreed to by our community. As of today, I'm going to use something similar to what I think Steve (AEAC) is using because most of us read his reviews. I also agree with FelixS that we need to include data on the environment that we do our tests in.
About 40 years ago, as an electronic technician, I supported an EPA noise study and had access to some very expensive test equipment and test facility. So I do have a good understanding of what it takes to do a precise test. Unfortunately most, if not all of us do not have access to that type of equipment and facilities today. If we had a basic, agreed to, test setup the passing of quantifiable information to other forum members would be simplified.
About 40 years ago, as an electronic technician, I supported an EPA noise study and had access to some very expensive test equipment and test facility. So I do have a good understanding of what it takes to do a precise test. Unfortunately most, if not all of us do not have access to that type of equipment and facilities today. If we had a basic, agreed to, test setup the passing of quantifiable information to other forum members would be simplified.
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This is a very informative article about the practical aspects of firearm noise testing.
https://www.montana.edu/rmaher/publications/routh_maher_asa_0516.pdf
I have fiddled with noise testing a bit, and found the environment has such a large impact on the measured sound level that controlling microphone location alone is not enough to assure directly comparable measurements. My solution is to establish a couple points that people might be familiar with, say a 10 meter springer and an unmoderated PCP, and show where the gun of interest falls within that spectrum. Most people would think that a moderated gun that produces the same sound level as a low powered springer would meet their requirements.
https://www.montana.edu/rmaher/publications/routh_maher_asa_0516.pdf
I have fiddled with noise testing a bit, and found the environment has such a large impact on the measured sound level that controlling microphone location alone is not enough to assure directly comparable measurements. My solution is to establish a couple points that people might be familiar with, say a 10 meter springer and an unmoderated PCP, and show where the gun of interest falls within that spectrum. Most people would think that a moderated gun that produces the same sound level as a low powered springer would meet their requirements.
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Why not take a clue from loudspeaker testing????
You want OPEN FIELD testing.
You want waterfall frequency/amplitude/angle time-decay plots.
Like this:
This is not something that reduces to a single number........
You want OPEN FIELD testing.
You want waterfall frequency/amplitude/angle time-decay plots.
Like this:
This is not something that reduces to a single number........
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Testing...outside...of an acoustic chamber is purely subjective. Means little in the world of infinity and jelly doughnuts.
No matter where the sensors are, how expensive the sensors are, out of doors is no place to test for sound coming from an object..!
With outside, or ambient noise that is an "uncontrollable factor", these types of tests are for fun only, with little basis in reality.
Mike
No matter where the sensors are, how expensive the sensors are, out of doors is no place to test for sound coming from an object..!
With outside, or ambient noise that is an "uncontrollable factor", these types of tests are for fun only, with little basis in reality.
Mike
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This is an excellent thread — thanks for starting this discussion, Frank! 
Recently I assembled a Silencer Specs Table for 50 AG commercial silencers, and so I was of course interested not only in size, price, and looks, but also in performance.
And I realized quickly: It is very very unlikely to compare test results across different performance tests.
Say airgunner A1 conducts silencer Test-1 producing a loudness number for silencer S1 (in dB, or whatever unit of measure he chooses).
Now airgunner A2 wants to know if his silencer S2 is more or less loud than S1. So he conducts a silencer Test-2 and gets a loudness number.
➔ It is very very unlikely that the two loudness numbers will be comparable — because the test protocols (conditions, equipment) will almost always be wildly different.
However, there is a solution.... I find that there is a method that will produce useful data, even with different test protocols:
A silencer test that compares enough silencer models using the same conditions for all silencers tested — such a test will produce data that can be comparable within the confines of the test.
➔ The challenge is that whoever runs the test should have a good amount of silencers on hand....
I know mrbulk (Charlie) is one such airgunner who not only has a bunch of silencers, but also invest time to test them — and to publish his results for us. THANKS!
The above mentioned tests by Silent Thunder Ordnance (STO) are another good example.
There are a few more tests I mention in the Specs Table.
To make this testing happen we could pool our silencers — send them to a trusted individual who is interested in conducting the tests — and then we get a both broad and comparable test results. It worked great for STO's test, why wouldn't it work for us at the AGN community?
It probably still is a good idea to figure out WHAT exactly we want to measure and HOW. For example:
▪ (1a) How loud a gun with different silencers sounds to the shooter — because he doesn't like loud noises. ➔ Measure the sound close to the action.
▪ (1b) Or — How loud a gun with different silencers sounds to the neighbors or the quarry — because we don't want to spook them. ➔ Measure the sound a good ways away from the muzzle.
▪ (2) How much the sound still sounds like a shot — or something else non-dangerous — for the benefits of the neighbors again. ➔ This is obviously a very subjective criterium, but there are some ways to measure this to some extent, I believe.
▪ (3) What kind of guns we are trying to silence: (a) Big bores (.30 and up) — to just get them a little more ear-friendly. (b) Medium powered guns (30-40FPE). (c) Low powered guns (15-25FPE). (d) Very low powered guns, like for the basement (sub 10FPE) — to silence them (almost) completely.
The power of the gun and the presence or absence of a shroud will make a significant difference how well a certain silencer performs. At least that is what I gathered from the STO tests:
Each silencer seems to have a certain capacity where it performs fairly well — but beyond that capacity it will not.
For example:
Silencer S1 is a monster 10" can, 2" diameter.
Silencer S2 is half the size, a 5" dwarf with 1" dia.
When testing them with gun G1 at 30FPE — S2 does terrible compared to S1 ➔ S1 = 80dB | S2 = 100dB
However, when testing them with gun G2 at 15FPE the difference between S1 and S2 isn't that large anymore to warrant mounting a monster when a dwarf could do almost the same. ➔ S1 = 70dB | S2 = 78dB
If you have silencer test results, put them out there, plz.
Matthias
Recently I assembled a Silencer Specs Table for 50 AG commercial silencers, and so I was of course interested not only in size, price, and looks, but also in performance.
And I realized quickly: It is very very unlikely to compare test results across different performance tests. Say airgunner A1 conducts silencer Test-1 producing a loudness number for silencer S1 (in dB, or whatever unit of measure he chooses).
Now airgunner A2 wants to know if his silencer S2 is more or less loud than S1. So he conducts a silencer Test-2 and gets a loudness number.
➔ It is very very unlikely that the two loudness numbers will be comparable — because the test protocols (conditions, equipment) will almost always be wildly different.
However, there is a solution.... I find that there is a method that will produce useful data, even with different test protocols: A silencer test that compares enough silencer models using the same conditions for all silencers tested — such a test will produce data that can be comparable within the confines of the test.
➔ The challenge is that whoever runs the test should have a good amount of silencers on hand....
I know mrbulk (Charlie) is one such airgunner who not only has a bunch of silencers, but also invest time to test them — and to publish his results for us. THANKS! The above mentioned tests by Silent Thunder Ordnance (STO) are another good example. There are a few more tests I mention in the Specs Table. To make this testing happen we could pool our silencers — send them to a trusted individual who is interested in conducting the tests — and then we get a both broad and comparable test results. It worked great for STO's test, why wouldn't it work for us at the AGN community? It probably still is a good idea to figure out WHAT exactly we want to measure and HOW. For example:▪ (1a) How loud a gun with different silencers sounds to the shooter — because he doesn't like loud noises. ➔ Measure the sound close to the action.
▪ (1b) Or — How loud a gun with different silencers sounds to the neighbors or the quarry — because we don't want to spook them. ➔ Measure the sound a good ways away from the muzzle.
▪ (2) How much the sound still sounds like a shot — or something else non-dangerous — for the benefits of the neighbors again. ➔ This is obviously a very subjective criterium, but there are some ways to measure this to some extent, I believe.
▪ (3) What kind of guns we are trying to silence: (a) Big bores (.30 and up) — to just get them a little more ear-friendly. (b) Medium powered guns (30-40FPE). (c) Low powered guns (15-25FPE). (d) Very low powered guns, like for the basement (sub 10FPE) — to silence them (almost) completely.
The power of the gun and the presence or absence of a shroud will make a significant difference how well a certain silencer performs. At least that is what I gathered from the STO tests:Each silencer seems to have a certain capacity where it performs fairly well — but beyond that capacity it will not.
For example:
Silencer S1 is a monster 10" can, 2" diameter.
Silencer S2 is half the size, a 5" dwarf with 1" dia.
When testing them with gun G1 at 30FPE — S2 does terrible compared to S1 ➔ S1 = 80dB | S2 = 100dB
However, when testing them with gun G2 at 15FPE the difference between S1 and S2 isn't that large anymore to warrant mounting a monster when a dwarf could do almost the same. ➔ S1 = 70dB | S2 = 78dB
If you have silencer test results, put them out there, plz. Matthias
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I just test in the environment where I shoot, using just my ears. If I can't tell a difference then there's no practical difference regardless of what a sound pressure level meter says. This isn't a great approach if you're designing moderators for use by others, but I think it's a flawless approach for evaluating moderators for my own use.
GsT
GsT
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Here are some preliminary data showing relative levels of projected noise outdoors at 15 feet in front of the muzzle. I choose directly downrange as the microphone location because that is the direction in which sound projection is the greatest, and 15 feet because that would be far enough away to avoid the direct effects of the muzzle blast, yet close enough for me to run back and forth without too much effort.
As I said, my idea was to establish a commonly understood reference standard, in this case represented by my HW55. I included other guns just to confirm the test had sufficient sensitivity to distinguish what I perceived to be louder guns from the HW55. I didn't pursue it further due to my fear that trying to get any consensus on a meaningful test protocol would be neigh unto impossible.
Included in the data are both Db and sound pressure units. I felt the max sound pressure reading to be the one that came closest to what I was perceiving with my ears. The most interesting thing in these data is just how much quieter the HW55 at 560 fps is downrange than even the Streamline on low power. Also interesting is the fact that relatively high powered springers are not all that quiet. Which is not too surprising to me given that my wife tells me she can still hear me shooting my TX200 150 yards from the house. I doubt that would be true of the HW55.
As I said, my idea was to establish a commonly understood reference standard, in this case represented by my HW55. I included other guns just to confirm the test had sufficient sensitivity to distinguish what I perceived to be louder guns from the HW55. I didn't pursue it further due to my fear that trying to get any consensus on a meaningful test protocol would be neigh unto impossible.
Included in the data are both Db and sound pressure units. I felt the max sound pressure reading to be the one that came closest to what I was perceiving with my ears. The most interesting thing in these data is just how much quieter the HW55 at 560 fps is downrange than even the Streamline on low power. Also interesting is the fact that relatively high powered springers are not all that quiet. Which is not too surprising to me given that my wife tells me she can still hear me shooting my TX200 150 yards from the house. I doubt that would be true of the HW55.
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You could run your hot rod weekend car or motorcycle or lawn mower (idle) or shop compressor or vacuum cleaner outside whenever you shoot if you got nosey busybody anti-gun neighbors when you shoot... to raise that ambient noise level...not too obvious that way...
Tempted to record the sound of a pellet smacking a bird and loop it spaced out and play the recording off and on daily to train the neighbors ears to not even bother...whenever they hear that WHACK!!!
Tempted to record the sound of a pellet smacking a bird and loop it spaced out and play the recording off and on daily to train the neighbors ears to not even bother...whenever they hear that WHACK!!!
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I have friendly neighbors and frequently ask the closest couple if they hear anything. Even with the SK-19 (loud!) they only hear the wack on the steel plate of my backstop, and nothing when I'm shooting into dirt.
BTW, checking with the neighbors, filling them in, and assuring them that you're not using their home as a backstop is 1000x better than having an excellent moderator.
GsT
BTW, checking with the neighbors, filling them in, and assuring them that you're not using their home as a backstop is 1000x better than having an excellent moderator.
GsT
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The cheap amazon db meters most use in reviews are far from scientific. True sound metering test equipment can be very costly and labor intensive to get "scientific" results. Different locations such as surroundings can give highly different results from one test to another using the same Airgun.
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OPEN FIELD TESTING -- used for ALL types of emission testing - they ONLY way to avoid room interactions.
Either this or an anechoic chamber -- who has one of those handy????
I know you all like to reinvent the wheel with simple "alternatives" but the scientific/engineering community already knows how to make these measurements......
My take on the sound meters that are generally affordable and available to the public, they're all junk. I have also found that the nature of the sound, as altered by a suppressor, is at least equally important as the volume. If the sound is a bang, even at low volume, it may be detected as a shot. But, a louder sound without any signature bang, is probably more acceptable as a back yard gun. My most stealthy rifle is a Taipan Veteran with a Donny Sumo added to the Veteran moderator.
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I have to agree with @elh0102 and others. I work as a industrial hygienist at times as part of my EHS program manager role. And professional grade equipment is far more expensive most people are willing to use, but more than what most people need. Imagine a Stanley drive vs a DeWalt, which is 2 to 4 times of the Stanley, but there is a reason for it, amateur vs professional / serious user. Also, a signature crack of thunder will catch someone’s attention more than a “rolling rumble”, and you can compare this to a crack of thunder vs background thunder even if it is as loud.
Also, I agree, my Taipan Veteran Compact with also a Sumo on it, seriously makes no noise with a setting below 30 ft/lbs except for the crack of the pellet hitting the target.
Also, I agree, my Taipan Veteran Compact with also a Sumo on it, seriously makes no noise with a setting below 30 ft/lbs except for the crack of the pellet hitting the target.
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