Author Topic: How to Record a Gunshot with zoom H6?  (Read 9539 times)

Brawl

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How to Record a Gunshot with zoom H6?
« on: March 31, 2014, 11:47:48 PM »
I need to record the sound of a gun shot, my friends have a gun (with "no real bullets") but the sound is the same as the original bullets.
I have the zoom H6 but I do not know which volumes are the best to record such a loud sound. Maybe I will have only one chance to record it (only one bullet) so I wish to start with the right settings.

Thanks for help. :)

Audionut

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Re: How to Record a Gunshot with zoom H6?
« Reply #1 on: April 01, 2014, 03:36:01 AM »
Which weapon is it?

Sound works on a logarithmic scale.  For each doubling of distance between yourself and the weapon, subtract 3dB*.
Calculate the expected SPL, and set the H6 to an appropriate setting, that leaves some overhead.

*Note:  This is also effected by surroundings.  If you are in an enclosed space, you may only want to subtract 1dB, to be on the safe side.

edit:

Looks like the rated Maximum SPL using the XY mic, is 136dB.
Judging from the data above, the minimum SPL you will encounter is 150dB.

Best case scenario, you need to be at least 32 meters away.
The -20 PAD won't fix compression of the mic diaphragm.
Don't use any of the compression or limiting settings.

Can you describe the recording surroundings?

mixmastermike

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Re: How to Record a Gunshot with zoom H6?
« Reply #2 on: April 01, 2014, 03:48:54 AM »
Use the -20 db PAD :D

dmilligan

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Re: How to Record a Gunshot with zoom H6?
« Reply #3 on: April 01, 2014, 06:21:27 PM »
Can you describe the recording surroundings?
This. Very important.

The sound a gun makes is nearly a perfect impulse. Which is totally uninteresting to listen to and contains basically no information. Mostly what you actually hear and associate with the sound of a gun is the impulse response of the acoustical environment it was fired in (basically the echo).

This means that the sound you record will basically have everything to do with the environment you record in and almost nothing to do with the actual gun itself or the sound it makes (other than some guns basically just being louder than others, i.e. the impulse is stronger).

Given this, it makes much more sense to simply record a much softer sound that is also approximately an impulse function, in the same acoustical environment you plan on using this audio for (matching the scene you're shooting or whatever). Or even simply convolving an impulse with an impulse response reverb model of an environment similar to the one you're shooting in (see: http://en.wikipedia.org/wiki/Convolution_reverb). That article also gives some ideas for alternatives for creating an impulse response such as an electric spark or popping a balloon.

If you have to place the mic far away from the gun or muffle it to prevent damaging it from too much SPL, then you won't really get an accurate representation of the impulse response of the environment near the gun. Being able to be much closer to a softer sound is probably going to give you much better results (depending of course on your scene you're planning on using this audio in, if you want the gun to sound far off, then by all means record a real gun from far away).

albert-e

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Re: How to Record a Gunshot with zoom H6?
« Reply #4 on: April 01, 2014, 09:27:45 PM »
Audio dub the gunshot sound in post processing. There are gun sound effects around for free. My "two-cents" advice.

mageye

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Re: How to Record a Gunshot with zoom H6?
« Reply #5 on: April 01, 2014, 10:30:05 PM »
Audio dub the gunshot sound in post processing. There are gun sound effects around for free. My "two-cents" advice.

I totally agree. It, of course, depends on what kind of 'realism' you are looking for here. I think the sound recordings/fx used in Saving Private Ryan are excellent because they are well recorded and sound more real (IMHO).

Most hollywood films seem to use hyper gun sounds that don't seem to have any connection to the guns that are being fired. Often when you hear guns from real footage on the news the gunfire sounds very flat (and tame) compared to the movies.

Real or not, the sounds used in hollywood are effective in the dramatisation of events.

There's plenty of well recorded foley out there. It all depends on what kind of impact you want to make. Real or hyperreal.
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Brawl

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Re: How to Record a Gunshot with zoom H6?
« Reply #6 on: April 03, 2014, 02:38:21 PM »
Thanks for your advices. Is it possible to damage the Zoom H6 XY microphones if the loudnes of the sound is too much close to the device?
If yes, I will search for the gun shot in internet. Thanks again for your help!

mageye

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Re: How to Record a Gunshot with zoom H6?
« Reply #7 on: April 03, 2014, 03:27:49 PM »
Is it possible to damage the Zoom H6 XY microphones if the loudnes of the sound is too much close to the device?

Possible but unlikely I would think. I mean if it was that damaging it would be ripping your ear drum apart wouldn't it?
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Brawl

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Re: How to Record a Gunshot with zoom H6?
« Reply #8 on: April 03, 2014, 07:18:53 PM »
Possible but unlikely I would think. I mean if it was that damaging it would be ripping your ear drum apart wouldn't it?
one of my friends said that some of he's firends shot a bullet for the new year day last year but they did it in the wrong way... what does it mean? this gun was "Blank shots gun" (the same king of bullet that I need to record in the next days)  they shot with the window closed. after that shot they where deaf for 3-4 days.
Do you have any idea if for high end production sound designers uses special protection for very loud sounds (for them and for theyr microphones I mean)?

albert-e

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Re: How to Record a Gunshot with zoom H6?
« Reply #9 on: April 03, 2014, 09:37:51 PM »
one of my friends said that some of he's firends shot a bullet for the new year day last year but they did it in the wrong way... what does it mean? this gun was "Blank shots gun" (the same king of bullet that I need to record in the next days)  they shot with the window closed. after that shot they where deaf for 3-4 days.
Do you have any idea if for high end production sound designers uses special protection for very loud sounds (for them and for theyr microphones I mean)?
Foley complements or replaces sound recorded on set at the time of the filming (known as field recording). The soundscape of most films uses a combination of both. A Foley artist is the person who creates this sound art. Foley artists use creativity to make viewers believe that the sound effects are actually real. The viewers should not be able to realize that the sound was not actually part of the filming process itself. Foley sounds are added to the film in post production after the film has been shot.The need for replacing or enhancing sounds in a film production arises from the fact that, very often, the original sounds captured during shooting are obstructed by noise or are not convincing enough to underscore the visual effect or action. For example, fist-fighting scenes in an action movie are usually staged by the stunt actors and therefore do not have the actual sounds of blows landing. Crashes and explosions are often added or enhanced at the post-production stage. The desired effect is to add back to the original soundtrack the sounds that were intended to be excluded during recording. By excluding these sounds during field recording, and then adding them back into the soundtrack during post-production, the editors have complete control over how each noise sounds, its quality, and the relative volume. Foley effects add depth and realism to the audio quality for multimedia sources, and simplify the synchronizing of sounds that would otherwise be tedious or downright impossible to manage.

Read about it at: http://en.wikipedia.org/wiki/Foley_(filmmaking)

Tons information/resources available on the web, if you know how to google and do a simple search, you'll find what you're looking for.

mageye

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Re: How to Record a Gunshot with zoom H6?
« Reply #10 on: April 04, 2014, 01:01:51 AM »
Damn! :-\ I think I need to apologise to my friend. Iv'e been beating the crap out of him for years to try and capture that 'movie' sound and now I find it's all trickery >:( :o ::)
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Audionut

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Re: How to Record a Gunshot with zoom H6?
« Reply #11 on: April 04, 2014, 03:41:52 AM »
Do you have any idea if for high end production sound designers uses special protection for very loud sounds (for them and for theyr microphones I mean)?

Ear protection.  Firing a weapon in an enclosed space, without ear protection, is just plain stupid.

http://www.freehearingtest.com/hia_gunfirenoise.shtml
Quote
Keep in mind that conversational speech is approximately 60-65 dB, and the threshold of pain is considered to be 140 dB. According to Dr. William Clark, Ph.D. senior research scientist in charge of the NOISE LABORATORY at the Central Institute for the Deaf in St. Louis, the damage caused by one shot from a .357 magnum pistol, which can expose a shooter to 165 dB for 2msec, is equivalent to over 40 hours in a noisy workplace.

For a microphone, distance is usually the only insulator you need*.

Something like this is used for room acoustics, but the same principles apply.  Make the sound quieter on one side of the panel, then the other.

*Note, There is a difference between the SPL where the diaphragm in the microphone will collapse, and the maximum obtainable SPL before the signal is clipped.