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-   -   The fader on my field recorder does not have numbers, does anyone know? (https://www.dvinfo.net/forum/all-things-audio/537509-fader-my-field-recorder-does-not-have-numbers-does-anyone-know.html)

Greg Miller October 25th, 2020 11:51 AM

Re: The fader on my field recorder does not have numbers, does anyone know?

Originally Posted by Ryan Elder (Post 1961807)
Well when you say 40 db may suit the NTG-3, do you mean a 40 db external attenuator, you buy for it?

That's what we've been talking about, isn't it?

Ryan Elder October 25th, 2020 12:18 PM

Re: The fader on my field recorder does not have numbers, does anyone know?
oh yes, I see that the ones that were given as well as some others online are universal and can be used with any mic which I didn't know there was. Thanks. I can get that!

I also talked to another person who's recorded sound and he says that if there is a noticeable difference in perspective from two feed versus 15 ft then I am doing something wrong since gunshots are so loud that there shouldn't be a difference. Is he right or no and the distance is a huge difference?

Brian Drysdale October 25th, 2020 12:47 PM

Re: The fader on my field recorder does not have numbers, does anyone know?
It depends on the environment. Firing a shot in a cathedral will have variations with distance as will in a forest, it's how it tails off that reveals the distance.

Greg Miller October 25th, 2020 01:05 PM

Re: The fader on my field recorder does not have numbers, does anyone know?
I've never recorded firearms.

With any sound source I've encountered, there is definitely a difference in perspective as you change distance. I suspect this is true for firearms as well. I can think of two reasons for this.

1.) The inverse square law. As you double the distance between the source and the mic, the level will drop by 6dB (1/4 the power, 1/2 the voltage). Compared to a reference of 2 feet, 16 feet that is 8 times as far away, so there will be an 18dB decrease in level of the direct sound from the muzzle. (1/64 as much power, 1/8 as much voltage)

BUT if you also have reflected sound from a building 100 feet away, it will change by one dB or less (because the distance changes no more than 15%). If you have reflected sound from a hillside 200 feet away, that reflection will change by roughly 1/2 dB or less.

So in theory the reflected sound changes very little, but the direct sound from the muzzle becomes relatively quieter. Of course if the hillside doesn't exist, or is very far away, or if the building is very small, then the overall sound will change less. In the middle of a desert, it would probably not be a noticeable change. (If you're recording something indoors where there's a lot of reflections from the walls, ceiling, floor, etc. then it will be a really big difference.) Describe the environment where you're shooting / recording.

2.) Proximity effect. The frequency response of directional mics is different at different frequencies. (This does not apply with omnis.) Proximity effect is especially audible when the distance approaches two or three feet. Since the NTG3 is decidedly directional, and you're talking about two feet as one of your distances, I suspect the recording at that distance would have noticeably more LF content than one made 15 feet away.

* The variable is that the above applies to sound waves that have some repetition of the waveform. But a gunshot also has a shock wave. I'm not sure how that propagates, except that the velocity is faster than the velocity of sound.

I've left a message for two firearms experts I know. I'll report what they have to say after I hear from them.

By all means, if anyone here has actually recorded firearms, I am curious about your actual experience.

Ryan Elder October 25th, 2020 01:28 PM

Re: The fader on my field recorder does not have numbers, does anyone know?
Oh okay, well I recorded on an outdoor range, which is basically a grass field. It seems too far away, at around 12 feet though, but was afraid to get closer because the audio was close to clipping, and I could turned the knobs any further down.

Greg Miller October 25th, 2020 01:58 PM

Re: The fader on my field recorder does not have numbers, does anyone know?
At the outdoor range, are there any hard objects nearby? A building? A protective roof? Vehicles? Just speculating here ...

Let's back up. Why are you recording gunshots? Are you just curious, or is this for use in one of your films?

If it's for a specific film, then in the script where is the gun fired? And where is the audience? It might be nice to match the script situation with the recording situation.

OTOH as other people have stated, gunshots in soundtracks are usually processed and combined sounds ... not simply one actual recording of one actual gunshot.

BTW, I just googled "recording gunshots." I got 579,000 results. Have you tried reading any sources like that? (And hasn't this suggestion been made before?)

Ryan Elder October 25th, 2020 02:15 PM

Re: The fader on my field recorder does not have numbers, does anyone know?
Yeah. I've tried looking for samples of gun shot sounds, but a lot of them sound further away perspective wise. I haven't storyboarded the shots where the gun is fired yet but they are in closer proximity in some shots, so I thought it would be best to get close perspective recording to begin with and then make them sound more distant in post, if need be.

I know that movies combine other sounds with the shot, but I thought I still needed a close perspective shot to begin with though. I was recording also for experience and practice as well, for much louder sounds, you don't hear everyday.

The shooting range is grass but sorrounding by treets on one side, and a pond on the other, but the pond is quiet.

Paul R Johnson October 25th, 2020 02:37 PM

Re: The fader on my field recorder does not have numbers, does anyone know?
Ryan, are you perhaps getting ahead of yourself here? Shoot the scene. Will the guns go bang, or will your actors have somebody shout bang which they respond to? Then you need to make a gunshot that sounds right for the scene and the viewpoint. Does it really warrant a recording session with real guns when there are thousands of alternate perspectives? Grab some of the truly great, dry and editable sound files and create whatever battle you want without going out of the door. Your fumbling and misunderstanding over quite basic audio concepts suggests sound effects will be a far more productive technique.

Greg Miller October 25th, 2020 04:35 PM

Re: The fader on my field recorder does not have numbers, does anyone know?
I have a close friend who shoots a lot ... everything from handguns to WWII German weapons. He asked some of the same questions I already asked (which have not been clearly answered).

In addition he said:

1.) You're using the wrong mic; use an omni. The "crack" from a gunshot is a shock wave created by the bullet. The shock wave originates at the bullet and travels along with the bullet. If you have a shotgun mic aimed at the end of the barrel, you will get a narrow and unrealistic recording.

2.) When he is on the shooting range, gunfire that sounds "most natural" to him is perhaps 20 to 50 feet distant. He suggests putting the mic (an omni) about 20 feet in front of the gun, and about 45 to the side, relative to the axis of the gun.

3.) Every weapon sounds different. You need to be recording the same model weapon that is pictured in your story. Do you even know this detail yet?

(I'm still waiting for a reply from the other ballistics expert.)

But yeah, what Paul said! IMHO you are naming the baby before you've even gotten the girl into bed (to put it politely). If you haven't storyboarded yet, then you're just doing random experiments now. Which is fine! We keep telling you to get out and try things. But ask yourself whether this is the best use of your time at the moment. If you want to make a movie


"and then make them sound more distant in post, if need be"
What makes you think you have the ability to do that, given that you don't even have a successful recording yet, and are not an expert at editing SFX? Paul is being realistic, working toward a practical goal. What is your most important goal? (This recalls my question a few weeks ago: do you want to make a movie, or talk about making a movie?)

Remember: Google has 579,000 results for "recording gunshots." Read some (or all) of them. This looks like a good starting point:

But you should have taken the initiative to eagerly do that on your own, without being spoon-fed.

Ryan Elder October 25th, 2020 06:17 PM

Re: The fader on my field recorder does not have numbers, does anyone know?
Oh okay, I just thought if I used my mics, that the sound effects will match the rest of the movie, rather than sounding more like more obvious stock sounds you can find online or in packages if that makes sense?

The reason why I went out to record before storyboarding the scene, is because they were doing the shooting at the range now, but will not go back for a while because of winter, so I seized the opportunity, even though it was before storyboarding

As for am omni mic, an omi records sounds from all directions, so wouldn't that make the gun sound less potent, as oppose to a shotgun mic, which cancel out sounds from different directions and concentrate more on the gun sound therefore?

Also, why 20 feet away with am omni? Am omni has a less narrow pick up pattern, so you are going to sound even more distant with that compared to a shotgun if 20 feet away, wouldn't you?

As for where I was aiming the mic, I was aiming it at the muzzle more so, because I thought most of the sound would be coming out of the barrel, but is that the wrong place to aim it?

Greg Miller October 25th, 2020 06:57 PM

Re: The fader on my field recorder does not have numbers, does anyone know?
I think he recommended an omni because he likes a more natural and distant sound. He says the gun will sound different from 20' than it does at 2' and he thinks 20' is closer to what most observers would hear. That might not be the sound you want for your track. If it sounds too wimpy for your taste, then boost the "potency" band on your EQ. But then again you don't have a track or even a storyboard at this point in time ...

EDIT: After doing some reading, I find that the speed of the projectile is important. It affects the time delay between when the shock wave reaches the mic and when the *sound* reaches the mic; and it affects the angle at which the shockwave reaches the mic.

I think he dislikes the narrow shotgun because, as I said, the shock wave comes from the bullet, which is moving. Presumably an omni at 20' would pick that up in a more uniform manner. As others have pointed out, a lot of movies do *not* use a realistic recording, they assemble something that sounds ... well, the way they want it to sound.

Please just read what I wrote, so I don't have to write it again.

EDIT: I've read a few dozen articles and posts about this topic now, and they've contained nearly that many different opinions. Many people record with multiple mics simultaneously but at different locations. I have to conclude that gunshots are extremely difficult to record, and take a lot of time and experience (and frequently a lot of post-production work, too). Probably the best results will not be obtained by an amateur with one mic and very limited knowledge and experience.

Ryan Elder October 25th, 2020 07:27 PM

Re: The fader on my field recorder does not have numbers, does anyone know?
Oh okay, thanks. I know a lot of movies use other sounds, it's I couldn't figure out what other sound, would sound quite like a gun shot, or how to create one, since it's a unique sound.

Greg Miller October 25th, 2020 09:49 PM

Re: The fader on my field recorder does not have numbers, does anyone know?
Why don't you read some of those 579,000 articles and find out for yourself ... if this is really how you want to spend your time right now.

Paul R Johnson October 26th, 2020 01:23 AM

Re: The fader on my field recorder does not have numbers, does anyone know?
Here, we don't have access to guns, so using a real gun involves an armourer. We have to pay a qualified person to do all things 'gun'. Even blank firing guns an even starting pistols are controlled. Oddly, part of my job is to licence the damn things and keep them secure, but I'm not the one who fires them. We've been simulating gunfire for years here because of the hassles. If the sound people need to experiment, here there is a real cost.

I loved Ryan's assertion that simulated gun noise doesn't sound real. Only the badly done ones don't sound real. I ran this topic past a friend who was in the services and he laughed because the first time he actually had people shoot at him for real in Afghanistan, he was amazed how totally unlike the movies it was.everything was smaller, and tighter sounding. Very little booming from small fallible weapons, unlike the movies. Sharp cracks, not sonic booms. I don't know because I've never heard a real gun firing bullets.

Does every US car shreak turning in or out of their driveways or swapping lanes on highways. Do they all squeal when you slam the brakes on? Our British ones don't. We must have different roads and tyres to US ones, and have differentials in rear axles, which don't seem to exist in Hollywood.

Brian Drysdale October 26th, 2020 01:44 AM

Re: The fader on my field recorder does not have numbers, does anyone know?
Gun shots vary, depending on the type of gun and their rate of fire. One feature of a real gun compared to a recorded gun, is that they are louder (unless you've got a turbo powered sound system) until you start to move away from them. If you listen to gun fire from war zones on the news, it's not like Hollywood sound, it's as Paul's friend says, short cracks.

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