Supersonic Bullet Cracks

[Trapper 0]

I've never heard the cracks in reality. Maybe there are people around who could tell us how far away from the bullet flight path the cracks are still being extremely audible.

This could be very help full to configure sound mods properly, because it's mostly the cracks that are triggering the automatic sound damping in ArmA.

Some opinions:

Quote[/b] ]I beg to differ on this.From experience,if you are shot at or near,the at 200yds to 300yds the crack is loud and you hear it first.Then you hear the boom from the rifle and it sounds more like a bang.The bullet is traveling supersonic,the boom is traveling subsonic causing a delay before you hear it.It is also a lot lower over distance but the sonic boom isnt. samuel.

Quote[/b] ]For Instance, the close-proximity sound is wholly different from what you hear at 100 meters. It does sound distinctly different from further ranges.

Quote[/b] ]It is a sonic boom/crack, that's what happen when an object break the sound barrier. If you go to an outdoor gun range and driving towards it from three hundred yards you hear the crack. However the closer you get to the rifle being shot the harder the crack can be detected due to noise from the control explosion inside the firearm. However it is still a crack. Firearms are very noisy and if you don't wear hearing protection you will go deaf.

There are two sounds that you can edit in ArmA:

supersonicCrackNear

supersonicCrackFar

How would you make them sound from your experiences and how far (distance of travelling projectile to player) would you configure each one of them to be barely audible?

[Gollum1 0]

In my experience, the crack (I would say it's more of a drawn-out crackling sound as it almost always echoes) is audible to everyone at several hundred meters and is very loud, but seems to quickly weaken after that. The bang itself is audible at many kilometers. For the operator, the mechanism of the weapon is also clearly audible and rivals the cartridges' bang. The sound seriously varies a LOT, being completely different depending on the weapon, distance, obstacles etc...

I've never played a game where the crackling sound of a firefight was accurately implemented, realistically the cracks and bangs are almost as loud at short distances and are very distinctly different sounds.

In combat, the operator may hear everything, something or nothing of his weapon, depending on adrenaline-induced auditory exclusion.

Quote[/b] ]The bullet is traveling supersonic,the boom is traveling subsonic causing a delay before you hear it.

How can a sound be travelling subsonically in air? I would assume that it would be travelling at the speed of sound. Correct me if I'm wrong.

[scubaman3D 0]

Trapper is probably right but also probably for the wrong reason. The speed that sound can travel is not constant and depends on the medium in which its moving. For example, on a super humid, summer night, sound travels at a different rate than it would on say, on a very dry winter night.

The conventional "speed of sound" speed, is defined by certain environmental conditions. Variations in those conditions will cause variations in the speed. So, yeah - its possible for sound to travel "subsonic" by the strict definition the speed of sound being ~343m/s.

[Trapper 0]

The quotes are opinions from some other boards I've googled and the authors can be wrong.

I think what he was trying to say is that the "powder boom" sound is traveling just at the speed of sound, while the bullet is flying super sonic. And because the super sonic crack is a shock wave which is moving as a cone shaped trail with the bullet, it's reaching (/created by) the observer earlier. Almost in the moment as the bullet travels by.

So looking into Wikipedia, regarding super sonic flight the crack causing air shock wave is following the projectile in a V shape and because of that it shouldn't be weakening until the projectile is slowed down by an obstacle.

Gollum1 are you saying the crack is audible/there over hundreds of meters no matter where you are or is that only true if you're still near the flight path while far away from the gun?

Because of it's cone shape the traveling shock wave/crack shouldn't be heard in front of the projectile and neither behind the gun.

The stationary shock/crack of initially breaking the sound barrier should be a part of the slow traveling "powder boom". Which is overall traveling kilometers farther than the crack as you said.

Very important would be the answer on the question of how large the diameter of the dragged traveling shock wave cone behind the projectile is. Respectively how radial far away from the path of a flying projectile do you hear the crack?

What was your relative position to the gun&flight path when you noticed the cracks hundred of meters away?

[Average Joe 0]

Sitting in BUTTS, I can tell you a 5.56 afew metres above your head makes ahelluva noise, I couldnt tell you from different distances because lets face it I didnt fancy wandering anywhere with those things whizzing above you.

As far as realism I believe PR for BF2 does a good effort of making you jump afew feet in the air when you know their close.

[Trapper 0]

Based on all this I would go for a radius of max 5m around the flying projectile now for the loud supersonic cracks and 10m for the dispersing crack.

That would especially help telling when someone is shooting at you.

Objections?

EDIT:

Mh, or maybe up to 250m for the dispersing crack but at conspicuous low volume.

[Gollum1 0]

Quote[/b] ]Mh, or maybe up to 250m for the dispersing crack but at conspicuous low volume.

As I said, the dispersing crack is actually quite loud at this distance (from all directions), almost rivalling the bang of the weapon. After this distance the sound starts to weaken considerably but even then it is very audible. I don't own ArmA so I don't know how realistic/useful this "dispersing crack" sound parameter is. I will only get myself lost if I start commenting on the physics aspect of it.

Quote[/b] ]Sitting in BUTTS

What is BUTTS?

Quote[/b] ]Gollum1 are you saying the crack is audible/there over hundreds of meters no matter where you are or is that only true if you're still near the flight path while far away from the gun?

The direction relative to the flight path doesn't matter significantly for about over 25m (?) distances. It is very audible from all directions. I don't have much experience of the very close-range cracks, so all I can say is that they are there and they are very loud. I'm sorry if my opinions sound a bit too wishy-washy, I haven't observed it systematically or even purposefully.

[dm 9]

Quote[/b] ]Sitting in BUTTS

What is BUTTS?

Butts is the protected target end of the range, they're getting less common now, what with electronic target ranges taking over, but they are still common.

I've been "shot at" in butts too, and have to agree with Average Joe's observations.

[Trapper 0]

Well, I'll make a ArmA video of my idea of a M249 then, for you to listen to.

The main problem in ArmA is, that crack sounds are always making the player character deaf every time they are audible at his position.

So if you make the player hear every single crack of a battle around him over far distance, it's possibly highly realistic but lowering the whole sound engine volume to my dislikening.

[Clavicula_nox4817 0]

None of this takes into consideration "auditory exclusion," which is, of course, the audial form of tunnel vision which tends to occur to soldiers in combat. It takes three common forms, which are generally dependent upon the level of stress.

[Gollum1 0]

None of this takes into consideration "auditory exclusion," which is, of course, the audial form of tunnel vision which tends to occur to soldiers in combat. It takes three common forms, which are generally dependent upon the level of stress.

Impossible to practically (non-annoyingly) take into account in a game, though. The effects of auditory exclusion vary wildly depending on the person and stress level (as you said).

[Espectro (DayZ) 0]

Quote[/b] ]Sitting in BUTTS

What is BUTTS?

Butts is the protected target end of the range, they're getting less common now, what with electronic target ranges taking over, but they are still common.

I've been "shot at" in butts too, and have to agree with Average Joe's observations.

I Concur

[Clavicula_nox4817 0]

None of this takes into consideration "auditory exclusion," which is, of course, the audial form of tunnel vision which tends to occur to soldiers in combat. It takes three common forms, which are generally dependent upon the level of stress.

Impossible to practically (non-annoyingly) take into account in a game, though. The effects of auditory exclusion vary wildly depending on the person and stress level (as you said).

Yeah, unfortunate, isn't it?

[Second 0]

What makes it annoying to implent such "auditory exclusion"? To my understandment some games uses it already... Strenght in which bangs and shouts are played is altered.

I am using it alot, that auditory exclusion thing... It's my wife and her constant babbling

[Gollum1 0]

What makes it annoying to implent such "auditory exclusion"? To my understandment some games uses it already... Strenght in which bangs and shouts are played is altered.

What games would that be and exactly how do they simulate it?

[Trapper 0]

Here's a video now.

Unfortunately I had to find out that the crack sounds and the sound damping is absolutely wicked to configure. Many things seem to be hardcoded.

Crackfar sound class can't be really influenced in it's travel distance. Only a constant volume over the whole travel distance for this sound can be affected.

Cracknear sound class can be influenced in it's travel range, but it can be only "amplified" to travel between 0m and 25m not more.

Crackfar is mostly replaced by cracknear at 25m or closer to the flightpath, but also at slightly further distances when your head is still turned towards the gun.

Sound damping is triggered whenever Cracknear is played. Salvos get it up more easily.

Configuring Cracknear to 0/off disables the sound damping near projectile flightpath while crackfar sound is still played up from 0m. This could be a solution for the AH-6 minigun: To disable the cracknear sound of it. But maybe there's another hardcoded barrier hidden, I didn't test it anymore.

Hours of experimenting make me think this was all fond hope.

Hopefully the video will sound realistically to you and BIS hardcoded something decent.

http://files.filefront.com/crackswmv/;11810358;/fileinfo.html

If you download the video, it's at 640x480.

PS:

If BIS wouldn't have included this desultory sound damping than I would recreate my own auditory exclusion like always in the past: By turning up the volume 'till it hurts. After a short while my individual auditory exclusion is noticeable then.

[SWAT_CDN 0]

Trapper

Which weapon is that firing?

I will attempt to get a recording of a M16, M240 and a M249 being fired in a test room.

(Installing some equipment, where they make the above, as we speak)

What I can say has more "bass" to the sound.

We are actually working in a seperate building from where these weapons are being tested and it basicaly sounds like a "Big" "Hammer Drill" pounding it's way through a concrete wall.

[Second 0]

What makes it annoying to implent such "auditory exclusion"? To my understandment some games uses it already... Strenght in which bangs and shouts are played is altered.

What games would that be and exactly how do they simulate it?

Well forexample in Crysis there is this "hearing protection" effect. I don't know what all it does, but atleast it adds hearing protection effect at near death states. Most new shooters seems to have this when character is close to death.

In Brothers in Arms i think they even sort of made familiar sounds easier to hear thru "hearing protection", so we could have Germans mumbling (actually shouting) next to us while some guy from player's squad was shouting player's name from distance (which is clearly to be heard).

I dont' know does this count as auditory exclusion (sort of low danger version of it), but in Assasin's Greed character could focus on dialog of two persons and sort of filter out the rest of noises from surroundings.

[Trapper 0]

It's a M249 firing with Mark's HiFi Sound mod.

I'm not working on any sound mod myself, recordings should be directed to him. Though HiFi Mod is aimed for a mix of realism and beauty, it isn't relying on plain recordings.

Oh and you're able to record the whole exit gun blast over there, but not directly super sonic bullet cracks, aren't you?

[SWAT_CDN 0]

Correct if I can record it would be from Behind or beside the weapon.

The weapons are tested inside a buiding, basically an indoor range.

[animosity242 1]

I know it's an old topic but I have something to add. I have been shot at (like directly at) on multiple occasions in Afghanistan, and I can say a couple of things. Recording a weapon sound or bullet crack is never accurate, it ALWAYS sounds different to a person. A bullet's super-sonic crack not a sound that fades or drags on, it ends as sharply as it began. It sounds VERY similar to those little popping fireworks that you throw on the ground (http://en.wikipedia.org/wiki/Bang_snaps). "Auditory exclusion"? No... You hear it every time.

The crack is barely audible if the round does not travel past you, otherwise, you can hear it a good 20m away.

@SWAT_CDN: What I can say has more "bass" to the sound. - That's from the weapon sound reverberating in a closed room, not from the crack.