Sound for gunfire?

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Indywannabe

Well-known member
This question has to do with the sound aspect of live gunfire on the set. We are using real firearms and blank ammo (shotgun, 38 revolver, semi-auto 9mm pistol)

...and yes there will be a firearms safety marshal on set.

(Using an HVX200 and AT 4073a)

My question has to do with how to record the sound. Because we don't have the permit yet, I've not been able to test what will happen when using a shotgun mic (no pun intended) tuned to capture the voice of the shooter, the BANG from the blank, and the racking of the gun. Is the bang going to sound full and rich if the mic is tuned to the voice, or will it just distort?

For the semi-auto pistol, we need full load or it will not cycle the next round.

Even though there is no such restriction with what load we use for the pump shotgun or the 38 revolver, I would like to keep the sound and muzzle flash on par with the semi-auto.

Any wisdom?
 
from my limited experience with blanks on set:
sound will be distorted.
replace the gunfire in post from library or record it wild on set to replace in post. even then it may be hard to find ideal conditions to not have it distort, and while you're figuring it out the nearest neighbor or business is calling the police to complain about the noise of repeated shots (best case sceneario).
 
Yeah, I strongly suspect a mic setup for voice will do a crap job of recording gunfire - it's one of those situations where the relative volumes in the real world don't match what you need in a finished movie.

Given how easy it is to find gunshot sounds, even for free on the internet, the simplest solution would definitely be to replace the real sounds in post. Nevertheless, if you have some separate audio recording gear, it wouldn't be silly to to take it on set and use it just for recording the gunfire - especially if the set has some odd acoustics which all the sound needs to match. The resulting sound files should be pretty easy to drop in over the main mike sound in post.
 
I think you guys are right. I plan to use 2 mics to capture the moment: one for voice and gun rack, and the other to capture the pop...then augment in post.

As for the neighbors, this is Texas, so everyone has a gun.

If I were in LA no one would even notice.
 
From my experience, to get a 'realistic' explosion (gun shot, fireworks...) you need to try and get as many mics as you can for layering in post. There are some great articles on filmsound.org (I think that's where I read them). Gun shots usually sound nothing like we are conditioned to expect unless you are successful in the post process (of course after successful capture). That or go the sound library route...A LOT less trouble but not as much fun :)
 
one of the most simple tried and tested techniques ive learned (somewhere back in time from a memeber here ..sorry would credit you but have no idea) in recording field sound doesnt require using any more equipment, but simply requires using what you have in more than one way at the same time. ..so heres what ive done for live gunfire. your HVX200 has two channels of audio right?. ..wrong ..actually it has 4. ..so what if you could use those 4 channels to record 4 different levels of audio using only one single offboard mic. well heres how you do it. channels 3 and 4 of the HVX ALWAYS record from the onboard stereo mic (whether you have channels 1 and 2 set to internal or not), and channels 1 and 2 can record from either input one or 2 or both from input 2 .. or 1 .. or whatever one it is they can both record from at the same time.. i dont have an hvx in front of me right now. :) ..so heres what you do. the main concern about gunfire is that its so loud and will clip almost anything unless its turned way down, but you want to pick up dialog at the same time, so youve got to be at normnal levels. ok ..so plug in your mic to whatever input it is that you can select CH1 and ch2 to at the same time. ..now take channel 1s levels , and level them for proper dialog audio. .. now take channel 2s audio levels and level them for gunfire.. (not hard here, just waste some rounds real quick, to get the levels set right is all). channel 1 should be turned up normally and channel 2 should be way down. if your audio is set to -60 db youve got more room to drop here for the gunfire as well.

..ok now youve got 4 different levels of audio going at once. ..just pay attention to your dialog as its most important and you should likely replace the gunfire in post anyway to punch it up. your channle 1 will be for dialog in post. your channel 2 will be for gunfire. your channel 3 will be HOT perspective audio for gunfire (loud , but since its recorded on camera it should sound more positional to how far away gunfire is) , and channel 4 will be quiet positional audio for gunfire. ..youve got 4 different levels. 2 coming off your shotgun, hypercardiod, whatever your booming .. and 2 more different levels because they are on camera and presumably further away from the action and STILL adhering to the differnent levels youve set for your channels 1 and 2 . 3 and 4 will be loud and quiet respectively as well, but from a different position which gives them different levels yet..

anyway, hopefully youve got where im going with this. basically even on a dvx you can use recording both ch1+2 from your mic and simply level them differently, when the HOT channel gets too HOT.. simply fade to the channel youve leveled for sounds that are louder.. thus ..saving your hiney. .. on the HVx you have the bonus of the internal mics recording as well so youve got 2 more perspective audio channels to mix from at will.

now of course you dont want to mix onboard for normal dialog, but this technique is for really loud sounds like shouting or gunfire or a loud crash ect. so even the onboard pics these things up well because they are simply so loud that it can get a good siganl even from being further from the action. .. anyway again. even though you could try to get it all on location , i do reccommend that you use the good audio you can get using these techniques with some mixing in post and punching it up with some hollywood gunfire sounds to really turn it into that great sounding audio your so used to hearing. ..unless you want a real life sort of sound to it. then this technique can just get you great location sounding audio.

.. using this technique with much closer levels between ch1 and 2 is great for regular dialog that may get a little too soft here, and a little too loud there.. just mix between your different channel levels and youve got a good solid normalization between them.
 
Charles Maynes is one of the undisputed masters of recording firearms, so look for any articles or writeups featuring his knowledge and/or work. For a good discussion of this, Viers' "The Sound Effects Bible" book is a good place to start. I'd also recommend searching rec.arts.movies.production.sound and the Yahoo! Sound Design mailing list.

What I've found is:
a) it's not about the number of mics - well, ok, it is - but rather a variety of positions for sonic coverage (Only have one mic? Move it up and down range for multiple takes. Takes a lot more time but can be done.)
b) film gun noises are as much about the reverberations as the gunshot itself (which sounds like a loud firecracker); most of the classic sounds we hear in film are recorded in canyons (refer to any Dirty Harry movie for that classic .44M sound as a good example)
c) it's super fun to do this, but time consuming
d) there are a TON of inexpensive SFX you can buy online if time's more precious
e) a good trick is to split a mic signal (better to use 2 mics in similar places) and pad one mic's input way down, with an inline pad or cranking your preamp gain way down. That will let one track possibly clip and the other will still be salvageable. The peaks on gunfire are insane.
f) most folks seem to like small condenser mics for this sort of thing, but others get creative with tube mics, boundary layer mics, you name it...

Personally, I've preferred to get the raw samples of others' sessions and do the layering/editing of the sound myself. I find that's a better compromise on time vs. cost. And, finally, let the story dictate the sound, not the actual caliber of the gun onscreen. You might not want to use a bazooka for a .22 pistol, sure, but maybe the sound of a .38 is just more dramatic..? (This depends on your audience, too, though!)
 
I realize you haven't asked about this, but I can't suggest strongly enough that you do NOT use real firearms. You say there will be a 'firearms safety marshall', but I don't know if that means someone appropriately licensed and trained, or just somebody charged with the duty of keeping an eye on things.

Either way, people have died on REAL Hollywood shoots, using highly paid, well trained, industry professional firearms safety personnel -- all because they used REAL guns loaded with blanks.

I can think of very few GOOD reasons to use REAL firearms on a film shoot. In fact, I can't think of any reason that would be worth risking someone's life for.
 
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