Airsoft science - Sound level testing
 

Airsoft "science" - Sound level testing

When firing, low sound signature = less chance of detection, less chance of the opponent hearing the shot coming (and ducking). After going thru an article in Airsoft International which tested the use of silencer, I had this idea:

Using a smart phone (android) with an app that measure sound level (in decibel),

I m gonna try a basic experiment:

I ll compare the sound level of some AEG and BA in my collection, with and without silencer,

Will do so while trying to maintain the same testing condition for all AEG and BA (same ammo type and weight, same position of the recording device (phone), thinking about placing it 3 feets from the piston impact point, indoor in my basement with minimal environmental noise (also minimise the noise of BB impact).

Anyone has hint / recommendation on how to improve this experiment? My app can also measure vibration, but not the "type" of noise (frequency: high pitched, etc)

Thanks

Test GBBRs, too! http://airsoftcanada.com/images/smil...01_icon_ok.gif

Why not put the mike downrange? 3 feet from the mechanism is not going to give you a fair read on what a target hears.

Something like this?

[Airsoft] The myth on suppressors silenced once and for all - YouTube

True, sadly, I m limited by the indoor space i have :( could go 20 ft max, worth it?

If you go without the BB can you go farther?

Not really, also, shooting a bb versus shooting dry would impact the noise level.

I ll try close to piston impact, with and without bb and same test, the furthest i can go indoor

You should use a computer to do the recording, with a proper mic and at a decent sampling rate. The problem with using these cheesy sound level apps is that just like those analog Amperage meters , they miss out on the spikes and detail. You might end up concluding that a given AEG is much louder on account of its gear spin-up or your phone's crappy microphone when in fact the overall report from the muzzle is quiet.

What would qualify as a good mike and software?

I think you need to understand the source of sound first.
AEG sound are from the motor, gear, nozzle predominately. Therefore the sound of bb leaving the barrel is kinda pointless. Try dry firing it and plug the barrel to test the difference in black n white.

Does the sound of the mechbox project down the barrel in any sizeable quantity? Buddy fired his KA M4 next to my head on auto at CQB (Think Blackhawk Down style) and my hearing wasn't normal for a couple of minutes. His motor height was off a lot though.

Want to see where the sound comes from?

Throw a towel over (or wrap it loosely around) the body of the gun and fire some shots....then without.

Then throw a thick towel over the muzzle and do the same. Don't plug it completely or else you'll cause an air brake in the cylinder.

From gas and AEG/PTWs a lot of the sound comes from the mechbox/action and a suppressor may change the overall tone/pitch of things but won't really suppress it. Works well on a BA though.

But by all means do the tests. It'd be a good reference to take a reading where the shooters ear would be as well.

I've done work on suppressing gas airsoft pistols VERY effectively. While at the cost of impact power and velocity, the guns i've done have been pretty much near inaudibility at 10 - 15 ft.

Sound like a TM mk23 to me :)

there is a noticeable difference muzzle side when you use a foam filled supressor... there's less of a snap, though most of the noise does come from the gearbox/motor.

Airsoft International made a great article that prove that a suppressor made a significant difference.

Issue 7 volume 11

http://www.ai-mag.com/blog/category/digital-versions/

Nope! WE HP35.

I buffered the valve knocker a bit, so it only farts out enough propane to fire the BB, but not cycle the action. Paired with a foam filled suppressor the gun is dead quiet. Only issue is that you have to manually cycle the slide prior to firing.

Heres a video.

http://youtu.be/-sKZyPk668g?t=1m31s

The audio doesn't really do justice to how quiet it really is. I'll elaborate on that further with another video this weekend.

Nice!!!

Dude, I've got pro recording equipement & software, remember my other hobby?

Also, I've got acces to an interior fireing range.

So what you waiting for? :P

Xmas vacation ahead! Je te PM

Another thing that helps reducing the sound signature is to put some strips of AC isolation foam. I did that with my g&g f2000. Since it's a bullpup the gearbox is closer to the body + all the foam strips inside the shell really muffle the sound of the gearbox. That coupled with my 8 inch silencer with foam inserts... the sound report is close to that of the tm mk23. This is the most quiet aeg that I have ever heard.

Faudra que tu m expliques ca pour le incoming Marui AUG :)

Yes sir ! ;-) The thing with the f2000 is that there is alot of room inside the shell for putting the foam all around the gearbox. I am not sure that there is enough space inside the aug cqb for the foam strips...Faudra regarder ça

I wonder if an AEG made out of polymer like G36, AUG, F2000 would be quieter than a full metal body AEG ? Metal seems to conduct sound better than plastic and plastic might be a better insulator.

One thing that works well at least psychoacoustically speaking is to have extremely fast trigger response. Compare a nicely shimmed AEG on a 7.4 to 14.8 (semi) and you'll see what I mean