Standardized Moderator Testing (free), Discussion Thread

[Firewalker]

Yes, I'll probably get blocked by OldSpook but I think any thread that doesn't have a discussion methodology is a disservice to the AGN so this thread will be the place where said comments can be posted in order to honor OS's wishes to keep his thread pure as well as give us a place to discuss the offer he presents us.

OK, GO!

 

[Firewalker]

Ill go first:

Thanks OS, this will be a great place to see the comparisons as you test the mods.

 

[Struckat]

Testing mods is fascinating. I am in the market for a 3/4” slip on for a Crossman/Walther 22 barrel on one of my Prods.

 

[bucketboy]

i make and test moderators and shrouds and I have come to the conclusion that there is no magic formula when it come to design. A moderator that works really well on one gun may not be as good on another even if the calibre and power are the same.
There are a few things that do improve performance, longer is better than shorter, fatter is better than thinner, smaller clearance through baffles and end cap is better than more clearance and a longer smaller diameter is better than a shorter fatter Dia.
Other factors that can make a difference is baffle spacing , baffle shape and wading materials. Some will argue that wading material doesn’t alter sound levels only tone, this is true in higher power airguns but in low to mid range power it makes a noticeable difference not only to the ear but also over a db meter.
Baffle shape, a simple flat washer works well in lower to mid power while k baffles is better as power increases.


Bb

 

[Stubbers]

i make and test moderators and shrouds and I have come to the conclusion that there is no magic formula when it come to design. A moderator that works really well on one gun may not be as good on another even if the calibre and power are the same.
There are a few things that do improve performance, longer is better than shorter, fatter is better than thinner, smaller clearance through baffles and end cap is better than more clearance and a longer smaller diameter is better than a shorter fatter Dia.
Other factors that can make a difference is baffle spacing , baffle shape and wading materials. Some will argue that wading material doesn’t alter sound levels only tone, this is true in higher power airguns but in low to mid range power it makes a noticeable difference not only to the ear but also over a db meter.
Baffle shape, a simple flat washer works well in lower to mid power while k baffles is better as power increases.


Bb

Amen, this should conclude the discussion of moderators forever more on this forum, because really people are chasing dragons trying to reduce the next DB with 'their new design', and often selling them to suckers in marketplace.

If any of these new designs/concepts were anything but snake oil they'd be patented and licensed to the highest bidder. Fact is, no one has nor will break new ground,, and if they were to, you wouldn't hear about it here until its sold through said highest bidder.

-Matt

 

[LDP]

@bucketboy I agree.

Amen, this should conclude the discussion of moderators forever more on this forum, because really people are chasing dragons trying to reduce the next DB with 'their new design', and often selling them to suckers in marketplace.

Exactly.

 

[WobblyHand]

Sounds an awful lot like what was said in 1899... There's nothing new to be invented. Have to say it was wrong in 1899, and wrong today. I agree however, that people are chasing dragons, and that there are suckers in the marketplace. But there's a lot more to invent yet, there's no need to shut down the Patent Office. Computers, cell phones and this forum are a counter example to this 1899 statement. As is Hiram Percy Maxim's invention, patented in 1908.

 

[LDP]

But there's a lot more to invent yet

True there is more to invent but is there more as far as this specific topic? I dont see any ground breaking improvements on this subject happening as far as quality of sound in either industry. Outside designs to make things look nicer and some conveniences over the years like different types of QD mounts but not much on sound. Theres a few on the market that hit new lows but again nothing substantial to the point of buy this and only this or across the board on every platform. Tests have proven (and I mean real tests not someone standing in their back yard using a phone app) that depending on the platform its being tested on the sound quality changes. In test A on a specific platform test subject A out performed the rest by 3 Db. Then in another test changing the test platform test subject A places third or at the bottom of a 10 sample test in sound reduction. So I dont think we will see any big improvements on this specific topic and certainly not in the airgun world it will come from the other industry where they use actual testing to try and make improvements. Just my opinion

By all means keep playing around and testing since it is fun and I plan on continuing to test and play with designs. I dont think there will be any improvements that are substantial or across the board on every platform but it will be fun trying.

 

[Stubbers]

Sounds an awful lot like what was said in 1899... There's nothing new to be invented. Have to say it was wrong in 1899, and wrong today. I agree however, that people are chasing dragons, and that there are suckers in the marketplace. But there's a lot more to invent yet, there's no need to shut down the Patent Office. Computers, cell phones and this forum are a counter example to this 1899 statement. As is Hiram Percy Maxim's invention, patented in 1908.
View attachment 448862

My sentiment is, I am personally tired of seeing 'the latest and greatest' being marketed here on the forums when its the same old same old, rinse and repeat. An individual true to both his nature and the nature of his accomplishments will work in private until boundaries are truly crossed, records are shattered, and all doubt of his work is easily swayed by tangible, patent-able proof. This type of development often takes years, not weeks/months. Those wishing to make a few quick bucks however, will throw as much crap at the wall to see what sticks, and boy oh boy there is a lot of crap on the wall when it comes to the ultimate airgun moderator around these parts. Seen it before with the STO's and called him out until he reduced his public appearances to zero...he still sells a lot of moderators and they do work, however he swore up and down his 'tech' was unrivaled and superior to anything and everything else...typical salesman.

At the rate there is a new 'latest and greatest' airgun moderator every other month, in 2-3 years time the best moderator should net true mouse fart silence...heck why aren't we there already? Seems to me airgun moderators achieve 68-71 db at best when kept within modest dimensions...

Pcp efficiency, modest power and a moderator of reasonable length, diameter, with a set of felt wrapped hair curlers as baffles does far more for an airguns report than any of the latest moderators brought to the forums in the last 5 years, and I'll bet the next 5 years too when coupled with a poorly tuned pcp operating at or near its peak power.

It would be nice to see moderators creep into the sub or low 60 db range but short of lobbing pellets at a mere 300-400 fps, I don't see it happening...and I'd love more than anything to be proven wrong.

-Matt

 

[bucketboy]

My sentiment is, I am personally tired of seeing 'the latest and greatest' being marketed here on the forums when its the same old same old, rinse and repeat. An individual true to both his nature and the nature of his accomplishments will work in private until boundaries are truly crossed, records are shattered, and all doubt of his work is easily swayed by tangible, patent-able proof. This type of development often takes years, not weeks/months. Those wishing to make a few quick bucks however, will throw as much crap at the wall to see what sticks, and boy oh boy there is a lot of crap on the wall when it comes to the ultimate airgun moderator around these parts. Seen it before with the STO's and called him out until he reduced his public appearances to zero...he still sells a lot of moderators and they do work, however he swore up and down his 'tech' was unrivaled and superior to anything and everything else...typical salesman.

At the rate there is a new 'latest and greatest' airgun moderator every other month, in 2-3 years time the best moderator should net true mouse fart silence...heck why aren't we there already? Seems to me airgun moderators achieve 68-71 db at best when kept within modest dimensions...

Pcp efficiency, modest power and a moderator of reasonable length, diameter, with a set of felt wrapped hair curlers as baffles does far more for an airguns report than any of the latest moderators brought to the forums in the last 5 years, and I'll bet the next 5 years too when coupled with a poorly tuned pcp operating at or near its peak power.

It would be nice to see moderators creep into the sub or low 60 db range but short of lobbing pellets at a mere 300-400 fps, I don't see it happening...and I'd love more than anything to be proven wrong.

-Matt

I agree entirely with this post and even if there is a moderator that could reduce the report to zero you will never be able to reduce the whizz of the projectile. While out hunting with my friends all of whom have really quiet guns, I can hear every shot they make from 100 yards away, from the pellet flying through the air and hitting home.

Here is a test for any moderator, stick a piece of masking tape over the endcap and fire a pellet through it (a good way to test for concentricity) if you can hear the paper tear, you have a quiet moderator

Bb

 

[WobblyHand]

At the rate there is a new 'latest and greatest' airgun moderator every other month, in 2-3 years time the best moderator should net true mouse fart silence...heck why aren't we there already? Seems to me airgun moderators achieve 68-71 db at best when kept within modest dimensions...

-Matt

Probably because most individuals, myself included, haven't done the engineering, analysis and testing necessary to understand enough to make the right kinds of changes. Most of the work I have seen is "seat of the pants". That's not to say there hasn't been legitimate hard work involved, and many flashes of insight. There are a lot of members that have tried to make better performing moderators. Sometimes you get lucky, but most of the time this approach is incremental at best, and a step backwards at worst.

There has to be a better way to figure this out. It's a tough multi faceted problem, that depends on a lot of things. To sort it all out would require a large time investment, a lot of knowledge about multiple disciplines, and quite a bit of fabrication and testing.

But, yes, I agree, there's a lot of hucksterism on forums, especially on moderators, and it gets tiresome. Would be good to do reasonable tests on them. There's been many attempts at this, some far better than others. To do it correctly is hard work.

As of the moment, short of a full MIL-STD test, the best attempt (that I know of) has been by @OldSpook. He's improved his testing with some suggestions from this subforum. One could argue that his test and the MIL-STD test have different objectives, but at least it is documented, methodical, and repeatable, with equipment that is accessible to many. I applaud his efforts in this area, to get meaningful relative quantitative measurement results. This, in my opinion, is a reasonable way to cut through the marketing BS, and make fair comparisons of moderators, on a common platform. Then we AG owners can make more informed decisions on how to part with our hard earned cash.

Sure, different moderators perform differently on different AG's. Why is that? It would be useful to know why - because then maybe we can make better and more robust designs. If one doesn't fundamentally understand the problem, it's likely the solution will be elusive... My two cents. Peace.

 

[OldSpook]

Sure, different moderators perform differently on different AG's. Why is that? It would be useful to know why - because then maybe we can make better and more robust designs. If one doesn't fundamentally understand the problem, it's likely the solution will be elusive... My two cents. Peace.

Absolutely nailed it!

The argument that one moderator performs differently on different rifles begs the question, "why?"

The only way to answer that question is to study that moderator and others like it on different rifles.

Compressed gas simulations (the Blender freeware can do that) would help greatly in visualizing air flows.

People who make the assertion that the problem is random are simply making an excuse for not being able or willing to do the analysis.

 

[Stubbers]

Probably because most individuals, myself included, haven't done the engineering, analysis and testing necessary to understand enough to make the right kinds of changes. Most of the work I have seen is "seat of the pants". That's not to say there hasn't been legitimate hard work involved, and many flashes of insight. There are a lot of members that have tried to make better performing moderators. Sometimes you get lucky, but most of the time this approach is incremental at best, and a step backwards at worst.

There has to be a better way to figure this out. It's a tough multi faceted problem, that depends on a lot of things. To sort it all out would require a large time investment, a lot of knowledge about multiple disciplines, and quite a bit of fabrication and testing.

But, yes, I agree, there's a lot of hucksterism on forums, especially on moderators, and it gets tiresome. Would be good to do reasonable tests on them. There's been many attempts at this, some far better than others. To do it correctly is hard work.

As of the moment, short of a full MIL-STD test, the best attempt (that I know of) has been by @OldSpook. He's improved his testing with some suggestions from this subforum. One could argue that his test and the MIL-STD test have different objectives, but at least it is documented, methodical, and repeatable, with equipment that is accessible to many. I applaud his efforts in this area, to get meaningful relative quantitative measurement results. This, in my opinion, is a reasonable way to cut through the marketing BS, and make fair comparisons of moderators, on a common platform. Then we AG owners can make more informed decisions on how to part with our hard earned cash.

Sure, different moderators perform differently on different AG's. Why is that? It would be useful to know why - because then maybe we can make better and more robust designs. If one doesn't fundamentally understand the problem, it's likely the solution will be elusive... My two cents. Peace.

If a moderator is developed which is digital and devises an aperture that closes after the pellet passes through to trap trailing gases, then a major leap forward may occur, but imo that would take

1) Incredible programming
2) Battery power
3) Expense
4) A method to slowly diffuse the trailing gases

Until then, the typical baffled moderator has little to no meat left on its bones to chew on. I sincerely hope to be proven wrong one day but that day isn't today.

-Matt

 

[OldSpook]

If a moderator is developed which is digital and devises an aperture that closes after the pellet passes through to trap trailing gases, then a major leap forward may occur, but imo that would take

1) Incredible programming
2) Battery power
3) Expense
4) A method to slowly diffuse the trailing gases

Until then, the typical baffled moderator has little to no meat left on its bones to chew on. I sincerely hope to be proven wrong one day but that day isn't today.

-Matt

You are absolutely right. Any old empty can is a pretty good moderator. Truth be known and I will explain that for you right now:

Decibels, being logarithmic scale, are deceptive. A smart guy like you with such strong opinions surely knows that. So if you reduce a signal by only 1 decibel that first decibel represents a reduction in power of 20 percent. The second decibel only represents a reduction of 17 MORE percent and the third only represents an additional 11 percent or so. Well that situation continues and by the time you have managed to reduce the signal by ONLY 6 decibels you have actually only reduced it by 75 percent. The first three represented a reduction of 50 percent total and the next three only represented half that and so forth. That means the last three decibels of a net reduction of 12 decibels only represents a total power reduction of 6.25 percent of the original signal. Literally ANYONE can build a moderator that cuts the signal by 3 dB (50%) AND all you have to do is take a survey of what is available in the market place to understand that. It's that last three decibels that separates the scientist from the snake oil.

So yeah, your are right, it's really hard to build a GOOD moderator if the only thing a moderator does is silence a muzzle blast. That's why you are willing to spend $200 or $250 bucks for an aluminum tube that costs a buck fifty with fifty cents worth of washers and some "magic" plastic hair curlers, inside of it. It's hard to beat a simple EMPTY can... just ask FX.

That said, a good moderator does more than just silence muzzle blast. A good moderator is lighter, smaller, does not affect POI and cleanly strips the gasses from around the projectile so that accuracy can actually be improved. A good moderator is a BLEND of these characteristics which satisfy the requirements of a specific shooting situation.

There is plenty of meat on that bone and if you would start looking for it, instead of saying "It can't be done." You might be able to help find it.

Until then your opinion is noted, now stand out of the way while we try to actually solve some of these problems.

~!~ Mike

 

[GeneT]

Unless and until someone can __*definitively*__ answer the question "What's the best moderator for my <whatever>" there's lots of room for study and exploration.

Yep, there are a lot of "all new, best yet, most marketed, ..." and there always will be - that's marketing. Marketing is a force so powerful that sometimes superior ideas get swept under the rug.

Silencers in powder burners have advanced by leaps and bounds in the last dozen or so years. Largely, I believe, due to utilizing modern manufacturing techniques and most importantly, serious CFD (Computational Fluid Dynamics) analysis. Makers of airgun moderators on the other hand seem content to rehash old designs (mostly old powder-burner designs) or copy new powder-burner designs. I'm hardly a CFD expert, but the dramatically reduced volume and temperature of 'air' nearly insists that the same geometries are not ideal in both cases...

In short, I think there's definitely room for substantial improvement in airgun moderators.

GsT

 

[Stubbers]

You are absolutely right. Any old empty can is a pretty good moderator. Truth be known and I will explain that for you right now:

Decibels, being logarithmic scale, are deceptive. A smart guy like you with such strong opinions surely knows that. So if you reduce a signal by only 1 decibel that first decibel represents a reduction in power of 20 percent. The second decibel only represents a reduction of 17 MORE percent and the third only represents an additional 11 percent or so. Well that situation continues and by the time you have managed to reduce the signal by ONLY 6 decibels you have actually only reduced it by 75 percent. The first three represented a reduction of 50 percent total and the next three only represented half that and so forth. That means the last three decibels of a net reduction of 12 decibels only represents a total power reduction of 6.25 percent of the original signal. Literally ANYONE can build a moderator that cuts the signal by 3 dB (50%) AND all you have to do is take a survey of what is available in the market place to understand that. It's that last three decibels that separates the scientist from the snake oil.

So yeah, your are right, it's really hard to build a GOOD moderator if the only thing a moderator does is silence a muzzle blast. That's why you are willing to spend $200 or $250 bucks for an aluminum tube that costs a buck fifty with fifty cents worth of washers and some "magic" plastic hair curlers, inside of it. It's hard to beat a simple EMPTY can... just ask FX.

That said, a good moderator does more than just silence muzzle blast. A good moderator is lighter, smaller, does not affect POI and cleanly strips the gasses from around the projectile so that accuracy can actually be improved. A good moderator is a BLEND of these characteristics which satisfy the requirements of a specific shooting situation.

There is plenty of meat on that bone and if you would start looking for it, instead of saying "It can't be done." You might be able to help find it.

Until then your opinion is noted, now stand out of the way while we try to actually solve some of these problems.

It's actually 20.57% for 1 db, and the 2nd db is 16.33%

So rounding properly as I was taught in grade school, that is 21% and 16%...

I'll stand where I please and speak my mind as I please, tyvm.


-Matt

 

[WobblyHand]

If a moderator is developed which is digital and devises an aperture that closes after the pellet passes through to trap trailing gases, then a major leap forward may occur, but imo that would take

1) Incredible programming
2) Battery power
3) Expense
4) A method to slowly diffuse the trailing gases

Until then, the typical baffled moderator has little to no meat left on its bones to chew on. I sincerely hope to be proven wrong one day but that day isn't today.

-Matt

Maybe that day is not today, but saying nothing is going to change is defeatist, IMHO. It's like being in 1899 again.

Your "crazy idea" isn't that far fetched. I do contest your comment on "incredible programming", actually that would be the easy part. The hard part is getting mechanical bits to move fast enough and maybe sealing. At 1000 fps, roughly one has 500 microseconds between pellet exiting the barrel and the pellet leaving the moderator, assuming a six inch moderator. That's tons of time, nearly forever!

I have a 600 MHz micro-controller on my desk, (on a 18mm x 35mm board, that costs $23) that could execute more than 300,000 instructions in that time. Battery life and actuators could be an issue. Perhaps one could harness some of the air to do work and reduce battery requirements. So not that crazy, but not that easy either.

As for a "typical" AG moderator, since no one knows what to fix, because they don't even understand the problem, things will stay stagnant a while. Maybe if the dynamics and vibrational modes are understood, it would be more apparent what to do. Been trying to get CFD installed on my computer and it's been tough sledding so far. So far CFD and a Mac aren't mixing that well. May have to boot my old linux machine and get it going again. That's one way towards insight, not by saying there's nothing new under the sun...

 

[OldSpook]

It's actually 20.57% for 1 db, and the 2nd db is 16.33%...your self proclaimed highness.

So rounding properly as I was taught in grade school, that is 21% and 16%...

I'll stand where I please and speak my mind as I please, tyvm.


-Matt

Oh! Look! You found the online dB to percent calculator... Well done.

I'm sorry. My bad? I figured just giving you approximations off the top of my head would work for you.
But your point is well made.

WE ALL ARE ALLOWED TO SPEAK OUR MINDS AS WE PLEASE... not just you.
Maybe you would do as well as I to try to remember that?

Just keep standing out there telling us how futile any effort to improve things is going to be.
We will leave the porch light on and the door open. You join us any time you want.

 

[Stubbers]

Maybe that day is not today, but saying nothing is going to change is defeatist, IMHO. It's like being in 1899 again.

Your "crazy idea" isn't that far fetched. I do contest your comment on "incredible programming", actually that would be the easy part. The hard part is getting mechanical bits to move fast enough and maybe sealing. At 1000 fps, roughly one has 500 microseconds between pellet exiting the barrel and the pellet leaving the moderator, assuming a six inch moderator. That's tons of time, nearly forever!

I have a 600 MHz micro-controller on my desk, (on a 18mm x 35mm board, that costs $23) that could execute more than 300,000 instructions in that time. Battery life and actuators could be an issue. Perhaps one could harness some of the air to do work and reduce battery requirements. So not that crazy, but not that easy either.

As for a "typical" AG moderator, since no one knows what to fix, because they don't even understand the problem, things will stay stagnant a while. Maybe if the dynamics and vibrational modes are understood, it would be more apparent what to do. Been trying to get CFD installed on my computer and it's been tough sledding so far. So far CFD and a Mac aren't mixing that well. May have to boot my old linux machine and get it going again. That's one way towards insight, not by saying there's nothing new under the sun...

Nothing defeatist about it from where I stand, I've made it clear I look forward to the day major leaps are made...its just not today, nor has there been any as of late...

I'm very unbiased here, the ones who are biased likely have a horse and a carriage to sell you...

-Matt

 

[OldSpook]

Nothing defeatist about it from where I stand, I've made it clear I look forward to the day major leaps are made...its just not today, nor has there been any as of late...

I'm very unbiased here, the ones who are biased likely have a horse and a carriage to sell you...

-Matt

No sir, they have ALREADY sold you that horse and carriage.
~|~ Mike