The Silent AEG thread.

[EscapisT]

After hours of searching, I have yet to come across a decent thread that offers AEG silencing tips other than gear modifications (like replacements or shimming), piston head/cylinder head modifications, motor modifications (replacement and adjustment) or suppressors/silencers (which will be elaborated on later).

Let's see what makes noise in an Auto Electric Gun.

Let us begin with the pull of the trigger. The contacts are linked, completing the circuit. From the battery, it runs into the motor through the + contact and out the - contact, back to the battery. It's that simple. The trigger is nothing but switch. And the fuse, a fuse.

The motor spins a set of 3 sequential gears, the last one pulling the piston back and releasing it. The piston is then pushed forwarded through the cylinder by the spring, sitting directly behind it. The piston slams (and it really SLAMS) against the cylinder head, where it rests to be picked back up by the last of the 3 gears, restarting the cycle.

So which elements of this cycle make noise?
We'll go over them in the order of the cycle.

So, starting from the battery, the motor is first. The ONLY way to silence it, according to my research is to replace it. Any noise caused by its misalignment is produced through the pinion and bevel gear, so allow me to classify it with gear noise. As far as noise related to the actual motor internals, there is little to no information on modification to the actual motor, and I do not know enough about them to suggest any.

Next up, is the gear noise. It's caused by the simple engagement of each individual tooth. And since there are 3 locations, well, 3 and 1/2 including the piston teeth (:P). It can be reduced by shimming the gears, reducing lateral play, thus "sharpening" the noise and shortening the sound of engagement.
Also, another method to consider is to replace the gears entirely to helical gears, which are quieter IF SHIMMED CORRECTLY (aka perfectly).

Next is the pistonhead slamming against the cylinder head, which can be made quieter by using an upgrade damper or a "Silent" piston/cylinder head set which has 2-sided reviews. There are 2 types of dampers that have proven effective with cushioning, silencing + adjusting of the angle of engagement.* There is the sorbothane pad (which is a foam/rubber hybrid) or one can use a piece of mousepad foam, cut the match the original pad.

*By adding a thicker damper, the piston rests a little farther back depending on the thickness of the damper it rests against. Get the right thickness, and it actually improves the angle the last gear engages the piston, aside from cushioning the impact and reducing noise.

Lastly, suppressors/silencers, aside from hiding a longer inner barrel, can *apparently* silence the sound coming out of the barrel, which, most notably, is the puff of air and some say the piston "slap" is also audible from the barrel. It's controversial, but theoretically, when looking at how real steel silencers work, they may prevail.


What has led me to make this thread is a video I found showcasing an ULTRA silent modified AEG. The poster, however, chooses not to reveal the methods used for commercial reasons, hoping to profit from the airsoft industry rather than feed it . Meh, respect to his silencing skills nonetheless.

YouTube - ‪Cumbria Airsoft Repair: Sound Proofing Mod‬‏
Author's mods:
JG HK416 custom
Clone Systema gearbox
SHS 13:1 high speed gears
King Arms Tappet plate
TM Cylinder head
TM Cylinder
TM Piston head
TM Polycarbonate piston (AoE adjusted for ROF - Swiss cheesed)
Prometheus M100 spring
G&P M140 motor
CA Socom silencer
Firefox 1500MaH 9.6v NiHm

So, to finish off, well go over what I've done to my aeg.

It's a Umarex/VFC HK416:
Modify M100 spring
Modify ultra piston
Sorbothane pad (tried the mousepad as well, works really nice)
King arms torque up Helical gears
PERFECT shim job
Modify anti-reversal latch
Complete rewire using 16awg silverplated wire + deans connectors
Kingarms precision Metal Hopup chamber
Guarder clear silicone bucking
9.6v 1600mah intellect


Next thing would be a new motor for me, but something tells me that the m4 in the video is silenced using a new method, unknown or heard of to the airsoft community. Because my gun after all my silencing mods is NOWHERE near as quiet.

[Azathoth]

What is not known is the truth behind what is listed in the parts of the video. Making a gun that silent is mindlessly simple if you are running a TM strength spring (~0.8j). Their are other aftermarket parts that are not really known such as cylinder heads with spring loaded shock buffers built into them (home made items see filairsoft, Japanese, and Chinese language forums).

Doing things such as swiss cheesing a piston is really not all that necessary now. maybe 6-10 years ago when material quality was awful in the polycarb and the other option was aluminum pistons that where very heavy. I wouldn't even think of swiss cheesing pistons now.

I've found that the faster the gun cycles the more 'quiet' it seems (i said seems not is more quiet). Also the tone that the gun makes will affect how 'loud' the gun will sound, which will affect how the sound carries.

In my mind guns go "BANG" even suppressed guns are very loud. Shooting subsonic rounds suppressed is still loud (as always some exceptions apply).

[Danke]

What's really not in the video is a before/same AEG without the change. It says right in the header the audio is messed up.

Where the mike was & what kind of mike, if the audio was changed during processing, it all comes into question.

[Azathoth]

Originally Posted by Danke

What's really not in the video is a before/same AEG without the change. It says right in the header the audio is messed up.

Where the mike was & what kind of mike, if the audio was changed during processing, it all comes into question.

that's very true. the same setup with a average to bad shim job can sound absolutely terrible. I have never seen anyone benchmark their AEG in a soundproof room or a recording studio under controlled conditions and do a before and after.

[EscapisT]

WOW, I didn't catch that about the audio being messed up.

Well aside from what is widely known to make an aeg silent, there isn't much on foam padding or "sound proofing". There is very little information about it, other than mentioning its effectiveness in space-vacant guns like the p90 or aug. I think there may be potential there.

http://www.c3airsoft.com/showthread....eg-12515.html?

There's a hearty post in there by cleric, where he pretty much nails evrything about the quiet AEG. Although most of the links he's posted are no longer good or require a password, one in particular mentioned something quite interesting.

"-Gearbox external stuffing. Mainly filling the space between the box and the body of the gun."

I know on an m4, there is very little room between the actual receiver and mechbox, but i think it's worth a shot if the right thickness of foam can be found. Also, i'm thinking about filling up the empty space in the gearbox, above and behind the spur gear. Some gearboxes have a solid metal block there filling up the space, but mine is just empty space which probably further resonates the gearbox sound.

Do you think there is potential in development in a mod like this? Are there different thicknesses available for materials like "dynamat"?

[Jcotter]

I found using a foam filled silencer works great. It's not silent but defiantly changes the noise from a crack to a thump. I really noticed the difference in my garage where the nosie had a chance to reverberate and seemed amplified. I was thinking of making a quick comparison video between the regular flash hider, kx3 and, silencer. ( silencer has 4 foam discs and are evenly spaced across a spring inside the tube) let me know if you're interested. I'm running a stock socom gear m4 with vfc internals.

[EscapisT]

Originally Posted by Jcotter

I found using a foam filled silencer works great. It's not silent but defiantly changes the noise from a crack to a thump. I really noticed the difference in my garage where the nosie had a chance to reverberate and seemed amplified. I was thinking of making a quick comparison video between the regular flash hider, kx3 and, silencer. ( silencer has 4 foam discs and are evenly spaced across a spring inside the tube) let me know if you're interested. I'm running a stock socom gear m4 with vfc internals.

I'd definitely like to hear it! You might the one who finally makes some hard evidence to end this whole silencer works/doesn't work ordeal!

[Ninja_En_Short]

Madbull silencer are usually very effective at changing the sound of a gun, directly in your hands you already notice the change, down on target it can be night and day.

[Kos-Mos]

That M4 from the video is nowhere near silent. The mic used to record the sound is just crap.

Some guns are easier to make silent than others. You listed most of the options and after all that, you should have a quite decent AEG.

After the mechbox "electric" sound is reduced, a longer inner barrel followed by a decent silencer makes all the difference. I had an ICS M4 with a Madbull G5 silencer. The same silencer what then installed on a TM P90. It changes the clak sound to a thud sound. From 2-3 feet, that sounds about as loud. But starting 10' away, you can barely hear the lower frequency noise because it does not travel as far and looses energy REALLY fast.

[ThunderCactus]

So if anyone is interested.....
Thundercustom has built and successfully tested an AEG air brake for the MASK piston head that reduces your piston noise to pretty well nothing. Like comparable to a stock VSR-10 G-spec.
The gears and motor, however, are your problem, unless you ask me to upgrade those too lol

Anyway, the downside of course is being limited to slow semi-auto fire (triggermaster with 1 second delay is perfect) due to the fact it takes much longer for the piston to return to it's original position.
But, coupled with suppressor (foam or not, doesn't matter), this thing makes 400fps AEG's dead silent on the receiving end.

[Jcotter]

Hey, I made this video today. I shot it in my garage to help amplify the sound. It was shot and edited on my iPhone. The sound was recorded with the internal iPhone mic and could have been better. I hope you find it helpful. This was my first video of any sort so comments and suggestions would be appreciated. Be gentile haha.
YouTube - ‪Airsoft sound comparison‬‏

[Kos-Mos]

Blank fire is useless to compare theses.

The sound is completely different, as any internal upgrades you installed is ineffective. Plus the air is going out as a regular flow instead of a presurized pop behind the BB.

Try again, but shoot this time... try not to shoot your phone.

[Jcotter]

Thanks for the heads up, I'm still pretty new to all of this. I can notice the difference while firing hot as well so I'll be sure to do a remake. Any other suggestions? I was thinking only doing down range and adding time codes for each one. Maybe a greater distance as well.

[Reckless]

Originally Posted by Kos-Mos

After the mechbox "electric" sound is reduced, a longer inner barrel followed by a decent silencer makes all the difference. I had an ICS M4 with a Madbull G5 silencer. The same silencer what then installed on a TM P90. It changes the clak sound to a thud sound. From 2-3 feet, that sounds about as loud. But starting 10' away, you can barely hear the lower frequency noise because it does not travel as far and looses energy REALLY fast.

this is a big thing too ... the pitch of the sound... it's also REALLY hard to judge the noise level of an aeg when your shooting and the thing is right up against your ear...

I've been right beside or shooting 2 or 3 aegs ... and they all sound very close to the same noise levels...

however 30-40ft out... they were VERY different ... the bone stock clone gun still sounded like a sewing machine you could hear the wind up and move/run/duck ... the mildly tuned guns (proper shimming, adjusted, etc) .. were alot harder to pick up and you only really heard the piston hit and the barrel pop and by then it was pretty much too late to react... the fully tuned and tweaked gun (helical gears, pads, good motor etc) with a foam filled silencer .. you barely got a pop.

now .. these are all outdoors guns, all running 380-406 fps ... so none of these guns engage under 60ft ... we all carry pistols .. so typically none of us engage under 100ft ... so same "test" @ 100ft

-the stocker @ 390fps ... still hear the windup, still hear the smacky poppy (this is actually still easy to hear 150ish ft out too ..)
-the mildly tuned/tweaked @ 380 fps ... barely hear the pop, not enough to react really, but enough to know where it came from (again harder to hear 150ish ft out.. but still able to get an idea where the shooting is coming from)
- the full on build @ 406fps ... you hear nothing, just bb's either hitting or going past... no real way to identify location other then if you see the bb's in flight. ... it's also good to note too the other 2 were firing single rounds, the full tuned model ended up with a nice feature on a full auto on off full pull a perfect double tap... so it was firing twice every time during this "test"


now.. this test wasn't scientific, it wasn't perfect... it was 3 completely different guns ... stocker was a kraken, mild tune was a metal bodied M4, and the full tune was an AUG ... that nice quiet Aug ... if you were the one firing it.. with the gearbox basically against your cheek.. you'd swear the whole forest and people the next town over could hear you.

[ThunderCactus]

I always thought my VSR was loud because my ear is pressed up against it.
Amos got mad at me and made me stand 15 feet away while he shot rounds past me, you couldn't even hear the rifle, only the BB.

But especially if you have a suppressor, just like real steal, the BB redirects the air coming out at an angle, and it gets caught inside the suppressor. Whereas if your blank fire, the air goes straight forward carrying the sound with it.
Also, your piston will always make more noise if it has no compressed air to slow it down.
You have to match your barrel length to your air volume so your piston is constantly riding that compressed cushion of air until it hits the cylinder head.
The only thing that won't get louder when dry firing is an air brake because it creates it's own cushion of air to slow down the piston.