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Using dB is misleading as well. People either are informed consumers or just like to think they are. Clearly using the 97% number is marketing, but then so is publishing dB numbers. The companies that don't publish any sound reduction numbers are onto something –– it reduces the number of internet asshats who badmouth your company. I don't trust the claims any silencer companies. It's a crooked industry, IMO. I honestly think 2-4 db difference in cans makes little difference as a feature. QD, weight, etc. are more important than the differences in sound reduction in any given rifle. Thats actually the point of it all A reduction of 3 db is cutting the energy in half So a can that do that has achieved not a little ,but much Try to look at it like this You have a cake take 3db away You now have a 1/2 cake That was much Now do it again You now have a 1/4 cake (the half of a half is 1/4) Do it again You now have a 1/8 cake again 1/16 you see, you will never get rid of the cake But the first part is always the biggest thats why the upper few DB is so important ,,if you care about the cans ability to suppress sound DB rules the show I think you example would make more sense if it was explained in terms of pie rather than cake. Just sayin'. |
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Mark white actually wrote that in an article. He was talking about distance of the meter from the weapon in testing, and as that usually occurs inside 40 meters most under 15 meters. As this is the case it may only accurately apply for 10-25 meters, I was using 30meters as the distance- obviously there is a point at which sound dampening efficiency loss happens with silencers- why not in the atmosphere as well?
To me the DB reduction figures tell me one thing clearly- whether something is quieter or louder. 1DB is something I barely can tell, 3DB's is something I can easily notice. To quantify 32Db reduction into 97% is something I cannot do. It doesn't sound like I'm listening to 3% of the original sound, so I think the logarithmic debate is something for scientists and not for human ears. I wasn't suggesting that 165 meters meant no sound, I was suggesting that 32 meter separation from a standard M4 is probably hearing safe. I would like to have someone test it to show how close to accurate that opinion is. I wouldn't be too surprised if 165 meters dropped sound to 104Db's the point wasn't to suggest it was constant forever, but to suggest ~32 meters likely drops ~32Db's. So if you are standing 32 meters away from an M4 in an open field without baffles, and someone fires facing to your front (away), the noise intensity at your ear is probably similar to what it will feel with most of the decent silencers on the market when you are firing with the ejection port 8 inches from your face. Basically communication on the internet is a giant fuckfest, and everyone's looking for a weak link to poke at. This doesn't mean I'm ignorant, or you are ignorant, what it does mean is we are all assholes. |
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If 97% bothers you then dont use db either becasue 50db and 100 db does not sound like twice the sound... which is what the layman will think if they know nothing of db. You cant just pick things you are more comfortable with and go with that based off perception... peole could just say light moves instantly becaue it appears to do so vs sound. Math and science are absoloutes. You can use them or not. Dont be upset because someone else uses them and you choose to not perform due diligence before jumping into a discussion.
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Using dB is misleading as well. People either are informed consumers or just like to think they are. Clearly using the 97% number is marketing, but then so is publishing dB numbers. The companies that don't publish any sound reduction numbers are onto something –– it reduces the number of internet asshats who badmouth your company. I don't trust the claims any silencer companies. It's a crooked industry, IMO. I honestly think 2-4 db difference in cans makes little difference as a feature. QD, weight, etc. are more important than the differences in sound reduction in any given rifle. Thats actually the point of it all A reduction of 3 db is cutting the energy in half So a can that do that has achieved not a little ,but much Try to look at it like this You have a cake take 3db away You now have a 1/2 cake That was much Now do it again You now have a 1/4 cake (the half of a half is 1/4) Do it again You now have a 1/8 cake again 1/16 you see, you will never get rid of the cake But the first part is always the biggest thats why the upper few DB is so important ,,if you care about the cans ability to suppress sound DB rules the show I think you example would make more sense if it was explained in terms of pie rather than cake. Just sayin'. Heck I dont think the db reduction figures are important AT ALL. The only thing ANY user cares about is the suppressed db figure. If you have a super loud rifle with a loud action that is painful to shoot who cares how many db are being removed? Its still loud. Would you rather have 32 db reduction on a 10.5" upper or 31 db reduction on a 20" upper from purely a perspective of sound to your ear? |
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If 97% bothers you then dont use db either becasue 50db and 100 db does not sound like twice the sound... which is what the layman will think if they know nothing of db. You cant just pick things you are more comfortable with and go with that based off perception... peole could just say light moves instantly becaue it appears to do so vs sound. Math and science are absoloutes. You can use them or not. Dont be upset because someone else uses them and you choose to not perform due diligence before jumping into a discussion. You already have a major authority on the subject suggesting why 50% would be more accurate to a human ear. I was aware of the logarithmic argument and cheated my honest estimate over to 75% in my head, before he posted that, but honestly it does sound closer to 50% when ears still often end up ringing on the Ar15 platform, and the weapon is still sounding like a quieter gunshot. I had a 7.62SD which is supposed to perform at up to 34.5DB's on a 5.56 weapon according to AAC, and my ears would still ring lightly and I could feel discomfort when firing it on my 10.5" gun. 3% ??? < that figure reminds me of machinist instructors talking about cutting RPMs "in theory". Science and theory and what actually occur can be two different things. In theory end mills shouldn't ever chatter, dull prematurely, overheat, work-harden materials, or blow up, but in reality sometimes they do. Scientifically speaking, my ears shouldn't have been ringing. (that 168DB report should become 133.5), well under hearing safe, above 98% reduction in sound. Maybe the action noise on an M4 is over 140? <if that's the excuse for this, 97% should not be used on devices 95% of customers put on M4's as that would then be missleading data. |
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Has anyone ever measured the action noise on an AR15 or M16? Try this ,lock the bolt back (on a empty gun ) put in earplugs give you gun a hug having the skull pressed against the buffertube then press the bolt catch =loud to the ear , could be to loud in the long run And no shoots was fired |
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Why would you guess? Do you not understand the logarithmic scale on which decibels are measured? Decibels are counted on a base-10 logarithmic scale. 1dB is measured as a sound intensity of 10^-12 Watts per square meter (or 20 micropascals of sound pressure). From there, everything is calculated as 10 raised to the power of the number of bels (1 bel = 10 decibels) of sound intensity. If the intensity of 1dB = 10^-12 W/m^2 = "I", then 10dB = 10^1 = 10 x I 20dB = 10^2 = 100 x I 30dB = 10^3 = 1000 x I 40dB = 10^4 = 10000 x I Etcetera. Thus, 160dB = 10^16 = 10000000000000000 x I, or 10 quadrillion times more intense than a sound of 1dB. 130dB = 10^13 x I, or 99.9% less intense than a 160dB sound. It is perfectly reasonable and correct to say that a 30dB can removes over 95% of sound intensity. Another way to do this math is that each additional decibel represents a 26% increase in sound intensity. Thus, a 160dB sound is 1.26^30 = 1026 times more intense than a 130dB sound. I bet if this guy described intercourse, he could suck the fun out of that too. |
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Has anyone ever measured the action noise on an AR15 or M16? That would be cool experiment. You would probably need to do this inside a building with the barrel noise insulated to the outside, and then again with a high-performance silencer to see if action noise was different with the silencer. That would also might tell us the sound level at which the theoretical maximum sound reduction transferable to the firer would be obtained. |
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Quoted: Quoted: Has anyone ever measured the action noise on an AR15 or M16? That would be cool experiment. You would probably need to do this inside a building with the barrel noise insulated to the outside, and then again with a high-performance silencer to see if action noise was different with the silencer. That would also might tell us the sound level at which the theoretical maximum sound reduction transferable to the firer would be obtained. A simpler experiment would be to measure AR15 bolt dropping on an empty chamber (or on a live round I suppose.) If I'm not mistaken, that's the noisiest part of the action. In my experience the action is noticeably quieter on the last round when shooting suppressed. Of course I could be mistaken. |
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Has anyone ever measured the action noise on an AR15 or M16? That would be cool experiment. You would probably need to do this inside a building with the barrel noise insulated to the outside, and then again with a high-performance silencer to see if action noise was different with the silencer. That would also might tell us the sound level at which the theoretical maximum sound reduction transferable to the firer would be obtained. A simpler experiment would be to measure AR15 bolt dropping on an empty chamber (or on a live round I suppose.) If I'm not mistaken, that's the noisiest part of the action. In my experience the action is noticeably quieter on the last round when shooting suppressed. Of course I could be mistaken. The bolt should lock back after the last round ,so only half the action cycle noise at the last shoot But if people is concerned of what reaches the inner ear ,they should trying what i did write in my post above without a shoot fired The action noise that travels through the stock to your skull is rather noisy (try that with a HK G3) |
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Quoted: Quoted: Quoted: Quoted: Has anyone ever measured the action noise on an AR15 or M16? That would be cool experiment. You would probably need to do this inside a building with the barrel noise insulated to the outside, and then again with a high-performance silencer to see if action noise was different with the silencer. That would also might tell us the sound level at which the theoretical maximum sound reduction transferable to the firer would be obtained. A simpler experiment would be to measure AR15 bolt dropping on an empty chamber (or on a live round I suppose.) If I'm not mistaken, that's the noisiest part of the action. In my experience the action is noticeably quieter on the last round when shooting suppressed. Of course I could be mistaken. The bolt should lock back after the last round ,so only half the action cycle noise at the last shoot But if people is concerned of what reaches the inner ear ,they should trying what i did write in my post above without a shoot fired The action noise that travels through the stock to your skull is rather noisy (try that with a HK G3 ) That's my point. The gun is noticeably quieter on the last round because the bolt is not slamming home. I believe the bolt dropping on the chamber is the noisiest part of the action, and I think if you can get to the point where the muzzle report is quieter than the bolt moving forward, then the gun can't get any quieter. I don't think the bolt moving back is going to be adding to the peak sound level at that point. But like I said, I could be wrong. |
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Yep ,but my point is that the noise transfered through the air isnt the same as the one going through the stock via the skull to the inner ear ,even if you use ear plugs or muffs the action noise will get to the inner ear
So a can that creates more back pressure that cycles the action harder/louder ,MIGHT be more quiet to the microphone and bystander .but louder to the shooter So it boils down to WHO is it we want to expose to less sound The shooter The bystander The target Whoever you dont want to know from where the shoot came |
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Quoted: Yep ,but my point is that the noise transfered through the air isnt the same as the one going through the stock via the skull to the inner ear ,even if you use ear plugs or muffs the action noise will get to the inner ear So a can that creates more back pressure that cycles the action harder/louder ,MIGHT be more quiet to the microphone and bystander .but louder to the shooter So it boils down to WHO is it we want to expose to less sound The shooter The bystander The target Whoever you dont want to know from where the shoot came I get what you're saying, but you can tune via springs/buffers the cyclic rate / BCG velocity, so it's real hard to do any comparisons in that regard. If you can get to the point that muzzle report is quieter than the action/gas at the ejection port, and get the action to be as quiet as possible (which isn't too quiet on an AR-15), then you're left with action noise and supersonic crack. I'd like to know what just the action noise would be 1m to the left. For that matter, metering it at the ejection port might be more useful. I only care about downrange or distant listeners myself. |
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Here's a little table of sound reduction in dB versus percentage reduction. I don't want to choose a side in the thread, but if you look at the % numbers, they get really murky really quick.
The formula is : %reduction = 1 / ( 2 ^ (-1 *dB/3)) dB %reduction -1 21% -2 37% -3 50% -4 60% -5 69% -6 75% -7 80% -8 84% -9 88% -10 90.1% -11 92.1% -12 93.8% -13 95.0% -14 96.1% -15 96.9% -16 97.5% -17 98.0% -18 98.4% -19 98.8% -20 99.02% -21 99.22% -22 99.38% -23 99.51% -24 99.61% -25 99.69% -26 99.75% -27 99.80% -28 99.84% -29 99.88% -30 99.90% -31 99.92% -32 99.938% -33 99.951% -34 99.961% -35 99.969% -36 99.976% -37 99.981% -38 99.985% -39 99.988% -40 99.990% -41 99.992% -42 99.994% EDIT : hopefully that fixed the formatting |
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Oh good! My 9mm can eliminates 100% of the noise- if you round 99.96 up!
Good, problem solved. This is the best way to describe reductions in noise! |
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Oh good! My 9mm can eliminates 100% of the noise- if you round 99.96 up! Good, problem solved. This is the best way to describe reductions in noise! One other thing to keep in mind is when some people say "3dB isn't a big difference" Well, the FIRST 3dB is very significant, 50% of the noise. The LAST 3dB, from 33 to 36dB for example, is 0.02% of the noise. HTH |
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What you just said REALLY makes it seem a silly way to express reductions.
So I can make a really bad Form1 suppressor that reduces it 3dB and actually say it reduces the noise by 50% when we know it doesn't. It reduces the intensity or energy by 50% but not what we as humans actually hear by 50% and we all know that... |
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I don't know if that formula is correct. Those numbers seem just a little generous.
I'm pretty sure you wouldn't notice much more than a tonal change in the sound up to 10 decibels on an M4. You could probably get 10Db's out of a 1.5" silencer 2.25" long with one baffle and an endcap and a .260" bore. |
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Has anyone ever measured the action noise on an AR15 or M16? Try this ,lock the bolt back (on a empty gun ) put in earplugs give you gun a hug having the skull pressed against the buffertube then press the bolt catch =loud to the ear , could be to loud in the long run And no shoots was fired You cant just measure the bolt closing on an empty chamber either. A bolt closing on an empty chamber makes my right ear RING every single time... it is painful to me. Closing when chambering a round is not loud or painful at ALL. |
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Oh good! My 9mm can eliminates 100% of the noise- if you round 99.96 up! Good, problem solved. This is the best way to describe reductions in noise! One other thing to keep in mind is when some people say "3dB isn't a big difference" Well, the FIRST 3dB is very significant, 50% of the noise. The LAST 3dB, from 33 to 36dB for example, is 0.02% of the noise. HTH That final few db can still be important though. Last Texas suppressor shoot SC_Texas shot a 07 SPR/M4 and I was standing 1 m left of muzzle. FRP hurt my ear and made it ring. The following shots did not and were MUCH more comfortable as far as perception. I still think its silly to argue against the mathmatical reality of what is energy reduction. Car 1 weighs 3000 pounds and has 400 HP/400 TQ. Car 2 weighs 5000 pounds and has 420 HP and 420 TQ... saying car 2 has more power is a fact... even though the end user will feel that car # 1 has much more power when driving. Car number 1 has 300 HP and 220 TQ. Car 2 has 295 HP and 295 TQ. Saying car 1 has more HP even though it will feel slower when driven does not change the fact it has still got more HP. The user's perception does not change the facts even when the perception is opposite the facts. |
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What you just said REALLY makes it seem a silly way to express reductions. So I can make a really bad Form1 suppressor that reduces it 3dB and actually say it reduces the noise by 50% when we know it doesn't. It reduces the intensity or energy by 50% but not what we as humans actually hear by 50% and we all know that... But it does reduce the noise by 50% Thats the point dont you get it ? Take the start number ,no matter what it is on a unsuppressed riffle Take 3 db away = half of the the sound you started with |
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What you just said REALLY makes it seem a silly way to express reductions. So I can make a really bad Form1 suppressor that reduces it 3dB and actually say it reduces the noise by 50% when we know it doesn't. It reduces the intensity or energy by 50% but not what we as humans actually hear by 50% and we all know that... Oh for crying out loud... |
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What you just said REALLY makes it seem a silly way to express reductions. So I can make a really bad Form1 suppressor that reduces it 3dB and actually say it reduces the noise by 50% when we know it doesn't. It reduces the intensity or energy by 50% but not what we as humans actually hear by 50% and we all know that... Oh for crying out loud... Yes, this is all akin to taking a 4" diameter PVC pipe to pour water on your head. You can drop it to a 3" diameter pipe and have what, half the amount of water technically, even though to most it would at first seem like 3/4... Point being, you can get all technical about exactly how much of a reduction it is but in the end, you are probably getting much more water dumped on your head than you want- same thing with these numbers. Even if it's a 50% reduction losing 3dBs, your ears still hear almost all of the noise- much more than you want to. |
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Here's my rule of "dB and what it sounds like" :
If you understand dB*, you aren't asking about a more practical rating. If you don't understand dB, shoot the damn can and buy it if you like it. *dB is on a log scale (3db = twice as loud) and dB measures power of the sound wave. To restate that, it measures power of the sound wave. dB does not relate, directly, to what any human ear will hear. dBa is more representative of what the TYPICAL (ie: not your) human ear hears. dB is a 100% accurate measurement - and it has a vague relation to what YOU PERSONALLY will hear. |
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Quoted: Quoted: Quoted: What you just said REALLY makes it seem a silly way to express reductions. So I can make a really bad Form1 suppressor that reduces it 3dB and actually say it reduces the noise by 50% when we know it doesn't. It reduces the intensity or energy by 50% but not what we as humans actually hear by 50% and we all know that... Oh for crying out loud... Yes, this is all akin to taking a 4" diameter PVC pipe to pour water on your head. You can drop it to a 3" diameter pipe and have what, half the amount of water technically, even though to most it would at first seem like 3/4... Point being, you can get all technical about exactly how much of a reduction it is but in the end, you are probably getting much more water dumped on your head than you want- same thing with these numbers. Even if it's a 50% reduction losing 3dBs, your ears still hear almost all of the noise- much more than you want to. So what exactly do you take issue with? Using a logarithmic scale to measure sound pressure? |
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In other words stand in an open field, fire an M4, then step 25 meters to the rear and have someone at the original location fire it again, now pick up a suppressed M4, fire it, and the sound intensity will probably feel similar to the unsuppressed at 25 meters. I think the suppressed gun at the shooter would sound a lot quieter than the unsuppressed gun at 25M. But yes, describing sound reduction as a percentage is going to confuse those who don't understand the details. For that matter, the same is true when giving dB figures. AAAAaaahhh. But one must not forget the intent of most advertising is NOT to remove confusion...but to SELL. That is why the "stats" are used. They are technically correct (read "true") so they can be used without negative legal ramifications, while running very little risk that anyone will actually understand. I remember what a college prof once told us about statistics, "Figures lie and liars figure". |
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What you just said REALLY makes it seem a silly way to express reductions. So I can make a really bad Form1 suppressor that reduces it 3dB and actually say it reduces the noise by 50% when we know it doesn't. It reduces the intensity or energy by 50% but not what we as humans actually hear by 50% and we all know that... Oh for crying out loud... Yes, this is all akin to taking a 4" diameter PVC pipe to pour water on your head. You can drop it to a 3" diameter pipe and have what, half the amount of water technically, even though to most it would at first seem like 3/4... Point being, you can get all technical about exactly how much of a reduction it is but in the end, you are probably getting much more water dumped on your head than you want- same thing with these numbers. Even if it's a 50% reduction losing 3dBs, your ears still hear almost all of the noise- much more than you want to. So what exactly do you take issue with? Using a logarithmic scale to measure sound pressure? Yes... this should not be allowed by GOD!!! |
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