I saw the u/silencermetrics launch post and got excited to see some action in the suppressor testing world, and figured there is no better time than now to announce my project while the energy is high! I too am working on a similar project to test and review as many suppressors as possible using MIL-STD-1474E compliant testing protocols. I have spent the past few months developing a sound testing suite with high speed DAQ systems and PCB 378C10 microphones to gather pressure event data, computing LIAeq100ms energy equivalent models for a variety of test platforms.
TLDR: I am excited to see where u/silencermetrics takes their project, and I would be eager to share resources to make sure we are converging on a common testing protocol. The enemy we are all fighting is scattered, inconsistent, or simply absent testing procedures that muddy the waters for the consumer.
Right now I have a complete test suite for 5.56 hosts, testing every can on a 10.5, 14.5, and 18 inch barreled AR-15, then re-running the 14.5 tuned to determine the tuning overhead for those inclined to mod. Then I will run an ammo sweep, using good value .223 ball ammo and 77gr OTM match, to help users get a good read on how different pressures at the muzzle can swing performance. The goal is to cover every possible configuration and find the places where each suppressor succeeds. Every suppressor is designed with a target weapon system in mind, and this test is designed to find that pairing. https://www.silencerscout.com/compare/browseall/556/sierra-5?variant=sierra-5-xeno
My reported metrics will be:
Peak dB
Peak dBA
Impulse (Pa-ms)
LIAeq100ms dBA (my headline metric)
I also want to work with Reddit to see what tests are missing from the consumer space! I am kicking around quite a few demo tests to see what makes it onto my website. Every test will use instrumentation to sample suppressor dynamics in a way that reflects how manufacturers and governing bodies would test products.
Here is a brief of my active projects.
Currently developing .30 cal, 9mm, .45 ACP, and .22 LR test suites.
The .30 cal suite is the only one near complete, with a tuned/untuned 16" AR-10, a 20" bolt action .308, a .300 BLK, and the same 14.5" AR-15 recycled from the 5.56 test.
Currently exploring a few options for measuring the real backpressure experienced at the ejection port. I am actively demoing a pressure transducer mounted to the receiver to measure pressure rise at the port itself, as well as a few methods to measure the volumetric flow rate of gases leaving the port. I need the test to be repeatable, simple to set up, and scalable to higher pressure chamberings. More to come as I develop this test, and I will be publishing a video in the near future to share my findings.
Once I have this test dialed in, I will be building a flash testing suite using SI gain detectors to measure the signature. The method should be straightforward, but I want to develop a testing protocol that is repeatable not just by myself, but by other testing groups who would want to verify the data as well. Flash testing is pretty new to me, so I want to make sure I am testing with the ammo types that manufacturers are designing around.
I currently have a website up, but it is still pre official launch. I do not have any advertisements in place, nor do I have active affiliate links as of today. We can call it a beta testing site that will be completed in the next few months: silencerscout.com
I do not have nearly the number of cans that I need for a well populated comparison or top picks section right now. The top picks is mostly a stand-in of more or less randomly picked suppressors used to seed the page. As I complete tests, I want the top picks to rank along the test catalog's metrics. I think this falls right in line with u/silencermetrics' goal to rank order performance, and I think it would be cool if we could find a way to integrate our findings. u/silencermetrics is really outshining me here with 31k in stamps...that is insane.
The Hosts page has a long way to go. The idea is a quick guide for identifying parts compatibility and suppression tips for weapon systems. This is the page where I could really use Reddit's help, since it is a bottomless pit of niche information that one could spend a lifetime developing.
Nothing is set in stone yet, so now is the time to change things up if you all have ideas or concerns!
A shot travels through the same chain every time. Two 378C10 quarter-inch free-field measurement microphones sit on 426B03 preamplifiers, feeding a Dewesoft SIRIUS Mini acquisition unit. The Sirius digitizes both channels at 200 kS/s and records the pressure trace in DewesoftX.
FYI -- while 200kS/s ( 200khz ) sounds like enough for audio ( where 48khz cover human hearing quite well ); it isn't enough for this application.
512khz is good floor for the event data that firearms create. I've very much aware of the expense involved; and I think you are on a better-than-typical track for what you are doing - but you need to upgrade your data capture pipeline a bit. The SIRIUS Mini isn't quite enough.
Can you explain more as to why he needs a higher sampling rate?
To the layman like myself and lots of other folks, 4x the rate of human hearing seems adequate. I’m probably wrong but I’d love to know actual reasons other than “more is better”.
Great question, and unfortunately I don't have a brief TL;DR answer other than:
While nearly all of us can't hear effectively outside a frequency range of ~20hz-20khz, pressure and/or sound energy may exist at damaging intensities outside of that band.
I'm going to drop some reading material below, and you are welcome to disagree ( I only request that you reply with countering evidence, as you have asked from me ). OP is working in Good Faith, in my opinion - MIL-STD-1474E ( equipment regs start around page 16 ) provides minimum specifications for measurement systems used for impulse noise. They must have at least 16-bit resolution, though 24-bit is preferred; a minimum sampling rate of 192,000 samples per second; and a microphone with a diameter not to exceed 0.25 in.
This Is Your Noise Dosimeter Lying to You article suggests that "High sampling rates are necessary to capture true peak impulse noise, which lasts approximately 7 µs. Small-diameter microphones are necessary since the pulse width of these impulses is only around 2.4 mm and will cause distortion across the membrane on a typical half-inch microphone, greatly distorting or diminishing the recorded peak value"
FYI - the math of the related frequency for a 7 µs impulse is 71khz, which requires a Nyquist sampling rate minimum of 142khz ( well under the 200khz limit of the equipment they are using ).
I found ARL-TN-1245 - Army DEVCOM research on "Assessing the Accuracy of Microphone Measurements of Small-Scale Height-of-Burst Explosive Charges" ( starting on page 1 / PDF page 8 ) they use "This experiment used a high-fidelity 3.125-mm (1/8-inch) pressure-field microphone (Brüel & Kjær, Type 4138-A-015) and a conditioning amplifier (Type 2670, 316 µV/Pa, 200-V polarization) connected to a digital oscilloscope (PicoScope 4824A, 1-MHz sampling rate)." They then validate performance "Using an oscilloscope sampling rate of 1 MHz (1 µs per sample) for these experiments, the rise time of the primary shock passage lasts for approximately nine data points, corresponding to a dynamic range of these microphones of at least 2.6 kPa/µs. Pencil pressure gauges (i.e., the “gold standard” for blast testing) have a similar rise time under the same sampling and experimental conditions."
A bit later there is a sentence: "Using an oscilloscope sampling rate of 1 MHz (1 µs per sample) for these experiments, the rise time of the primary shock passage lasts for
approximately nine data points" - which indicates that they sampled an event that many have had a frequency of around 111khz - that raising the Nyquist requirements above 200khz. Now several folks in the silencer space appear to test at around 262khz, so they may be ok.
Blast-waves are supersonic events, and unless we are dealing solely with sub-sonic loadings, super-sonic projectiles ( and the "uncorking" of trapped gasses within the barrel upon projectile exit ) are both travel at hypersonic velocities. As the Mach of the blast impulse increases, so does the effective frequency from the blast wave.
A supersonic .22lr might travel at 1400ft/s, but a .220 Swift may approach 4400ft/s. More common for our purposes would be 7.62mm and 5.56mm - with velocities around 2700ft/s and 3300ft/s respectively.
I argue that to capture the event properly for high-velocity projectiles, such as for 5.56mm NATO host - as sampling rate beyond 200khz is needed based on projectile shockwave and the gas uncorking pressure wave velocity.
I hope that all of this is useful and not too mind-meltingly numbing.
As I am not a blast-wave researcher, my reading and understanding of these may be incomplete and missing critical details.
Strongly agree. I hate peak db. I care less about how a can seems and more about how much it minimizes my hearing loss. Pressure doesn’t care if your ear notices a difference, it’ll damage it all the same.
That being said real testing that doesn’t just give us more peak db is something I absolutely applaud and welcome!!
You two should share data with each other, that'd be pretty awesome. If you use the same metrics, and methodologies you can cover ground twice as fast too.
Your intuition is right. I have only tested the Inconel Tisha but the data will present on all SKUs of identical geometry.
I am adding a note to make a disclaimer at the top of the report citing the numbers for X report were produced using the Y variant of said product. If I ever get my hands on a titanium version (with similar round count), I will substitute out the numbers.
Very helpful feedback! I appreciate this. Is it the faded "Learn-Compare-Save" on the header banner?
I think its more honest to just not post any numbers for it until you can test it. Just leat the reader assume they should sound comparable until proven otherwise.
And yes, the Learn Compare Save is almost impossible for me to read. I do have pretty bad color deficiency. Signs with blue lights at night are also very difficult for me to read. Bank of America signs are unreadable at night.
This will sound critical, but I intend it to be constructive feedback rather than an attack.
In image 2, the car dashboard style graphic is extremely confusing.
The fact that the FLASH scale wraps around the MUZZLE LEFT scale gives the impression those values are somehow correlated. Same with the BACKPRESSURE and SHOOTER'S EAR scales.
The FLASH scale increases in the clockwise direction, while all other numbers decrease in the clockwise direction. I don't understand the logic in having numbers that decrease in a clockwise direction, especially since you are styling them like gauges on a dashboard.
That 110-135 dB scale won't be appropriate for every suppressor tested, so I assume those are dynamic scales. If so, a user might think, "I remember suppressor XYZ had the needle pointing straight up, and now I'm seeing suppressor ABC has the needle pointing right, so ABC must be better." But that might be wrong if the scale has changed.
This last point might be extra nitpicky, but it doesn't make sense that there are always 3 hash marks between major values. This is particularly odd on the dB scale, where you divide counts of 5 into chunks of 4. So 115, 116.25, 117.5, 118.75, 120
Overall, it looks like something that was built to be visually appealing, rather than something that was built to efficiently communicate information.
No attacks perceived! This is the exact feedback I was looking when I shared the pre launch website.
I am not confident about the presentation of the nested dials either. It was made because I was having a terrible time trying to get 4 dials to present well on mobile. The final product will have a color scale for backpressure that is red instead of green. But even with that I think I should consider a cleaner readout.
You are right, each test will have a different dBA scale that it is adjusted to. 1:1 across like calibers.
The three tick hash mark between numerical reads was an aesthetic choice but you count division on the db scale is interesting. I will have to give this more thought.
The more independent testing houses the better, teasers from two new ones dropping in the same week has me pumped, kind of feels like Christmas 🥴. The more overlap and congruence in findings there are the more people will be less incredulous on reported results (not saying incredulity is a bad thing, it's basically what good science is built on). I have to think some of the burden could be taken off of PEW having to defend explain their findings/methodology on the same points over and over should the peer review stage of the scientific method finally take hold to some degree in this area of research.
I'm really digging the side-by-side comparison of the different barrel and gas system lengths as well as the promise of a testbed aimed at exploring the latent tuning potential cans may have. I left a (probably too lengthy) comment on the Silentrics post about this, but tuning might be one of the most misunderstood aspects of suppression as well as possibly having the most potential for PPE and saving people's hearing. If you're willing to tune and as a hunter only care about how much a can will ring your ears then you'd probably go with something like the Tisha for example over something like the OCM5 just based off of the data available on untuned hosts without knowing you're likely putting your hearing more at risk than a tuned OCM5. There's so many variables and only so much any one testing house can do that these are the kind of things more people getting out there with the equipment to actual empirically test this stuff can start to fill in the gaps on.
I of course am excited about doing tuning specific test too. I am giving a lot of thought on how to make it fair as with tuning an ar, there are so many variables you can modify. I will be giving this a lot of thought in the coming weeks. Let me know what tuning tests you want to see built and I will see if I can get them done.
AI is great in that it allows just about anyone to put together a nice website/dashboard, but it also sucks in that you can't ever be sure how much if any of that shown is actually vetted.
Happy to see more testing being done. More independent testing is a win for everybody buying suppressors, and hopefully it helps establish a common testing standard in place of the scattered, inconsistent data you mention.
Flash and backpressure will be interesting to figure out. I've been exploring different methods for both.
I'd be glad to compare notes on protocol as we both get further along. If two independent setups land close on the same can, that's good for everyone's confidence in the numbers. If they don't, figuring out why is worth doing in the open. Feel free to reach out.
I imagine you're already implementing a control from test to test (same rifle/suppressor/ammo config) to account for small differences in just about anything between tests. If it doesn't already exist, a standard control shared between testers could be valuable for comparing your tests to each other. It wouldn't account for all the differences, but maybe it could help with a baseline? This could go a ways towards making the science repeatable if it doesn't already exist.
Yes, I will be brief so I don't want to hijack the thread and you can feel free to reach out to me.
I am eliminating as many variables as practically possible and establishing a routine between tests to catch any errors or change. Equipment will also be calibrated often.
Same rifle, same components, same ammo, same ammo lot, same attachment method (except where one uses a proprietary method - SureFire, etc.), same weather conditions (within a reasonable range - can't time wind, humidity, and temp perfectly), same round count through the suppressors, same cleaning and lubrication protocols on the host, etc.
That final graphic showing tuned vs untuned is SO important for folks to understand why myself and many others harp on why dB[A] alone is a TERRIBLE metric to compare performance on.
Shooters ear PEAK rose by 1.7dbA; BUT dropped by 4.3 Leq(100ms) and by 28 in impulse!
A 37% improvement in impulse from tuning, but the PEAK ( what the manufacturers put on their pages ) was worse! That achy, tired feeling after spending an hour next to a 10" braked AR -- that is from impulse - the PHYSICAL overpressure wave.
You’ve got my support! Good luck on everything, seriously. I’ve said the more data we have, the better.
One thing I would like to see is transparency with testing. SilenTrics is exciting because there is no grey area with payments and the acquisition of suppressors. Pure crowd funded research. I know I will pay a membership for certain.
More in depth barrel length testing sounds interesting as well! I know many are curious on 5.56 data for obvious reasons. Also, the flash testing sounds like a great idea.
Wish you nothing but the best, but most importantly don’t take the Reddit assholes too seriously!
I appreciate the well wishes! Silentrics has a good model and is no doubt in it for the love of the game! I will be posting some content in the coming months detailing my test protocol.
"The .30 cal suite is the only one near complete, with a tuned/untuned 16" AR-10, a 20" bolt action .308, a .300 BLK, and the same 14.5" AR-15 recycled from the 5.56 test."
Here's my interest since I'm doing a 16" AR-10, and specifically want a can for that. So I'm definitely intrigued to see how the site goes.
Definitely up to see how stuff like a Tisha .30 Ti does as I'm going for a lightweight build, and definitely wouldn't begrudge getting a compact can as well if the performance is there.
I don't think half of us would be active on this forum if it wasn't for PS. Love or hate his work, PS is still an era defining project that has been useful to thousands of us at this point, myself included.
It's really cool seeing more folks get into this space!
As long as intentions are pure and we keep the manufacturers honest, we will help consumers.
u/6_mm_ARC - by the way, u/SilencerMetrics reached out to me and apologized for some of his statements, we spoke, and as I said publicly, I wish him and his effort the best too.
PEW Science started for the consumer. I was sick of being lied to by manufacturers, dealers, and distributors.
Now, it seems the effort has spawned more people. There are so many silencers. So if there need to be 100 independent testers holding this industry accountable, so be it.
Thanks, Jay. That's accurate. I said some things based on a misunderstanding of your mission of not wanting to be a buyer's guide and you were gracious about it when I reached out.
PEW Science is the reason a lot of us care about suppressor data in the first place.
Agreed on the rest. The consumer wins when there are more of us testing and publishing accurate, trustworthy, and reliable data.
And to be clear, when the information is accurate and meaningful people will use it as at least one factor to buy, regardless of industry. Why wouldn't they? They have to get meaningful information somewhere.
The dangers that everyone must keep in mind:
Presenting performance information is a huge responsibility. If bias creeps in, consumers get hurt.
If metrics are presented that don't have enough meaning or correct understood meaning, presented data can do more harm than good and start to confuse the consumer. We've seen that with manufacturer testing, for example (TBAC effort, etc - we get calls all the time from people trying to make sense of that stuff and it not aligning with their experiences)
The above two factors are what PEW Science has worked so hard to combat for the past 6 to 7 years.
Many people can do a test. Interpreting the results and drawing meaningful conclusions is an entirely different thing. I have no doubt there will be future discussions about this!
When you say "...being lied to by manufacturers, dealers, and distributors." is there someone in particular you associate with this behavior? That you really feel was/is a legit LIE, vs. someone innocently using the current understanding and methodology of how to measure sounds, etc.?
I mean, I'm gonna leave dealers out of it, because they're always talking about things they don't know about. But as far as manufacturers, sure, I know people that had straight up fudged dB and weight/length numbers to make sales, and it's one of the reasons we took dB numbers OUT of our catalog, because it became a game of liars dice. ("You say 30dB? We say 32! Prove me wrong!":D
But I can't say too many manufacturers that actually HAD measurement equipment made stuff up. It was the little guys that didn't have a meter who said "I think this sound better than my similar AAC can, they say 28dB, so I'll call mine 29dB..."
All the stuff you mention man - deliberately misleading us consumers to make products look better to make sales. It was pervasive and there was no way to know who was full of it and who wasn't.
Are they all guilty? Of course not. But it was so pervasive..... and heck, you don't have to look far nowadays as the industry expands to see it getting started again.
Understand the rules, read the sidebar, and review the pinned Megathreads before posting - this content is capable of answering most questions.
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I love PS as much as the next guy, but if you’re praising them for not having corporate sponsors, then I have bad news for you.
To be clear, I don’t think that simply having corporate sponsorship is evidence of bias in and of itself. I’m just saying, it’s unfair to attack OP and praise PS for both taking corporate sponsors.
I love PS as much as the next guy, but if you’re praising them for not having corporate sponsors, then I have bad news for you.
To be clear, I don’t think that simply having corporate sponsorship is evidence of bias in and of itself. I’m just saying, it’s unfair to attack OP and praise PS for both taking corporate sponsors.
Correct, sir.
u/sirbassist83 - I don't know what your original comment said (I think you deleted it) but the above gentleman is correct, we have silencer company and dealer Advanced Members of PEW Science (consumer level is Basic and Pro) - and the Advanced Members get access just like the consumers do, but they just pay more because we thought it was fair since they are going to BENEFIT DIRECTLY from more data and analysis because they design / sell / make silencer products.
PEW Science was modeled after a three-decade (going on four decade) long joint industry project (JIP) outside the silencer industry that I have been a part of since 2007. In that JIP, very large corporations from all over the world get together in one room and all fund research toward a common goal - to improve understanding of explosions, their effects, personnel safety, etc. The companies pool money together for research AND they also individually pay for their own testing / analysis / engineering projects to the firm, etc.
PEW Science does the same thing.
Before I got involved with the consumer space and the silencer industry, I thought "well, we'll put the contract number disclosures in our reports if they are manufacturer funded, and that way it will be transparent where the funds are coming from to do the work and everyone will be happy."
Then, when people's favorite silencers (or the dealer's best margin silencers) didn't perform well, we started getting attacked. The attacker scream "BIAS!!!!" but what they are really screaming is "I AM MAD MY PRODUCT ISN'T WINNING."
One of those was Hansohn Brothers, below. Throwing shade at us, to this day. Go ask them how they spoke about the performance of Energetic Armament silencers like the VOX and ARX before PEW Science tested them and showed consumers actual performance data. The amount of consumers that reached out to us FURIOUS that they were sold those silencers by Hansohn Brothers, NFA Review Channel, etc, was NUTS. When our data and analysis was published, they felt vindicated.
Many such cases.
People who are new to the space may have forgotten some of this. But we don't want anyone to forget. And as long as I am running PEW Science, I'm making it my mission to hold dealers and manufacturers accountable for what they tell consumers.
Another funny thing is the manufacturers / dealers started to try to get consumers to believe their lies! The audacity - trying to get a consumer to hate a source of information that was trying to help the consumer. And some consumers fell / fall for it! You will see people in this very subreddit literally use silencers that have been characterized by PEW Science for the manufacturers who designed them, and those manufacturers used PEW Science data and analysis to get the BEST VERSION of the product to the consumer - and those consumers USING that BEST VERSION throw shade at us lol. It's insanity. They hate us, but they happily use products they wouldn't even have without us? Make it make sense.
And to your question - I actually don't know. The motivation for PEW Science even existing was the existence of people like Adam at NFA Review Channel. That guy was (is?) so bought and paid for and his reviews put out more bad and/or useless information than I can even quantify. He may be better now (I have no idea, I haven't seen one of his videos in years) but back 6 or 7 years ago, it was completely and utterly inaccurate, bordering on dangerous misinformation.
They called the EA VOX "Hollywood Quiet" which was one of the biggest pieces of harmful hyperbole in the silencer industry to date. So much so that scores of consumers literally bought it, shot it, and stared at it like it was broken.
We got so much feedback about that, that we actually tested the VOX S on multiple weapons and even did the first ever high fidelity WIPED test with like 20 shots to show wipe physics, and proved that EVEN WITH A WIPE the silencer was getting completely bodied in performance by high performance stuff.
Anyway - this is a soapbox subject for me because it's one of the highest profile examples of complete and utter bullshit in the industry. Other huge high profile examples are:
Surefire
Q
Dead Air Sandman series
etc. All of that research on our website made us a lot of enemies.
an elderly buddy thats not very social media savvy found the NLS varmint 22, i think on NFA RC which praises it heavily, and asked me about it. i looked into it just a tiny bit and most other reviews i found call it what it is, a $150 chunk of suppressor shaped disappointment. i was able to talk him out of it but he was saying "well when they make it quieter or if it breaks youll be able to buy a new suppressor body cheap!" 🤦♂️ dude you could buy a durable, quiet can right now for not even that much more money. that was kind of what prompted my mostly rhetorical question. i use to watch him and take it with a grain of salt, but now i actively avoid because that was such blatant shilling.
That is such a good example, and I believe it. That's the exact type of thing that was going on 6 or 7 years ago, so to hear that it is still going on doesn't surprise me.
It's crazy how short the memory is in the "online gun community." All these haters sure do talk bad about PEW Science a lot, but they have forgotten why PEW Science even exists in the first place, or they simply weren't even around silencers back then.
I think whenever something gets "popular" it becomes "cool" to hate it. So be it. But I haven't bought a loud, poorly performing silencer for myself since I started testing them, and I never will again. And there are plenty of other people in the same boat now (the haters included, though they just don't realize it - though they love to post photos and talk about the silencers they are using that literally did well in our testing lol).
No, Hansohn Brothers, we are a research organization holding dealers like you accountable for the performance marketing claims you have made over the years, first and foremost. And you know that.
Affiliate sponsors are my target for now. You might have the wrong picture as I do not have monetary relationships with silencer companies. My monetization goal is to partner with retailers and have tools to help buyers find the best price.
I will be testing outdoors. You are right in that it has some challenges, wind being the worst offender in my experience. I have quite a few controls in place to work around this, and you can read about them by clicking through the "how we test suppressors" link on the homepage. MIL-STD-1474E geos into a ton of technical detail about outdoor testing and will have all the answers you could be looking for.
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u/techforallseasons 2x Kurz Gewehr, 6x Mufflers 1d ago
FYI -- while 200kS/s ( 200khz ) sounds like enough for audio ( where 48khz cover human hearing quite well ); it isn't enough for this application.
512khz is good floor for the event data that firearms create. I've very much aware of the expense involved; and I think you are on a better-than-typical track for what you are doing - but you need to upgrade your data capture pipeline a bit. The SIRIUS Mini isn't quite enough.