GAU-8/A Avenger sound(s) - Explanation needed

[derelor]

Hi!

 

I have a question regarding the GAU-8/A. Take this video, for example:

 

 

When the pilot fires the gun, two distinct sounds can be heard. Does anyone know the source for each sound? According to the video comments, we first hear bullets hitting the ground then the sound produced by the cannon. Is this true?

 

Thanks

[Sinky]

Yep, the rounds are supersonic so you will be dead before you hear the actual gun fire.

 

Take this video for example: http://www.youtube.com/watch?v=xuYmn_xYB78. There is an 8 second delay between the rounds hitting and the gun being heard. Starts at 22 seconds by the way.

Edited May 30, 2011 by Sinky

[Cougar12dk]

That would be the bullets flying past the cameraman and then you hear the buzz of the gun.

[159th_Viper]

Is this true?

 

Yes - bullets travel faster than the speed of sound. As an Ex-Infantry soldier (Platoon Commander) trust me when I say that you don't hear the rifle discharge/bullet that tags you.

[derelor]

So then the second sound comes from the sonic boom when the bullets goes through the speed of sound limit?

[159th_Viper]

So then the second sound comes from the sonic boom when the bullets goes through the speed of sound limit?

 

It's the sound of the cannon firing. Takes a while for the sound to travel to the mic on the ground.

[derelor]

The Avenger is known as the strongest cannon ever built in a US aircraft. Other than its 30mm caliber, its bullet speed is very fast. Whether in trainings or firepower demos, because of its high speed projectile, it can be seen that the target is destroyed first even before the crashing sound is heard. The noise does not come from the GAU-8/A; it comes from the sonic boom when the 30mm bullet goes through the speed of sound limit.

quoted from here

[Mud]

Three sounds should be heard from the cannon all in all.

 

1) The crack high pitched sound of the bullets breaking the sound barrier.

2) The sound of the bullets hitting the ground / target.

3) The sound of the GAU-8 firing.

 

The chronology of when you hear what all depends on your position related to the target and the cannon at the time.

[159th_Viper]

^^^

 

Quite so.

 

Regarding the vid clip, the first sound accordingly accounts for #1 and #2 in the above explanation and the second sound #3.

[Shootist]

I think the best sounds (and effects) you can see and hear of it are on that video of those Brits in the trenches who got a little too close for comfort.

[159th_Viper]

To concur with Shootist;

 

23 secs: Sonic Boom

24 - 27 secs: 30mm Impact

30 - 32 secs: GAU-8

 

xuYmn_xYB78

[Shootist]

Yeeeehaaaa!!! Ya gotta love it every time!

[dbeaty]

Even on Youtube, that sound of the GROWWL is awesome. It's the reverb and echo and bass...The ground impacts sounds like bombs exploding. I think I may need a much better Subwoofer, or something, but the sim doesn't really emulate that huge bass / echo very closely when playing back a gun engagement in Enemy view. But it looks about right!

[Snoopy]

As someone who hears the gun fired at Grand Bay Range (At Moody AFB) it is amazing! I've been at the range when they are firing as well as you can hear/see them from the flight line.

 

As everyone else has said, the first sound is the impact of the rounds hitting the ground/target, the second is from the rounds leaving the gun.

 

http://www.globalsecurity.org/military/facility/grand-bay.htm

[Rider1]

Here is another really nice range video.. Close up, great gun sounds, and TF whine.:thumbup:

Love how the flares have started a small grass fire.

 

 

[FLEXCopMNPD]

We used to hear the A10s firing off in the distance while I was a Fort Leonard Wood going through Engineer BOLC (Basic Officer Leaders Course). Gave me a hard on every time I heard it. It was cool to watch a two ship flight maneuvering to take shots on the range.

[Stryker]

To concur with Shootist;

 

23 secs: Sonic Boom

24 - 27 secs: 30mm Impact

30 - 32 secs: GAU-8

 

xuYmn_xYB78

Thanks for sharing that video, never seen it before. Talk about danger close! I remember when I was a kid out on Lake Bonaparte, NY near Fort Drum, you could hear the A-10 and other aircraft firing. Hearing that A-10 growl and have it reverberate off the valley on the lake added to the awesomeness. Best ambient noise ever while fishing lol

[Forest Rat]

Another video ...

[automag928]

The best comment on one of those youtube videos....that plane doesnt have a gun, that gun has a plane.

[skouras]

The best comment on one of those youtube videos....that plane doesnt have a gun, that gun has a plane.

:lol::thumbup:

[PhiXX]

another hog going dirty :thumbup:

[Hobnail]

Three sounds should be heard from the cannon all in all.

 

1) The crack high pitched sound of the bullets breaking the sound barrier.

2) The sound of the bullets hitting the ground / target.

3) The sound of the GAU-8 firing.

 

The chronology of when you hear what all depends on your position related to the target and the cannon at the time.

 

Pedantically speaking (1) is inaccurate. That sound is of the supersonic shockwave generated by the rounds passing the observer. The bullets are only ever slowing down once they exit the barrel and are therefore any initial "boom" as they "go supersonic" in the barrel merely forms part of the noise generated by the action of the gun. :smartass:

[hassata]

rk_8gXIpOMo

[Iceman2011]

That's more like it hobnail, unless the crackling sound travels faster than speed of sound lol