Forums

    9 posts

  • avatar
    8 sounds
    4 posts
    Best way of recording firearms, explosives, etc up close?


    Hey there. First I will brief you all on my setup- I am relying on Goldwave editor on my computer as the recorder, and using an Audio Technica AT2020 USB microphone.

    How would I go about setting things up (both physically, as in noise screens, positioning etc on the mic itself), as well as in the audio editors recording interface?

    What I want to do is record firework sounds up close as well as firearms(guns). I have tried this before, but with little positive outcome- both the firearms and firecrackers/fireworks were too loud and concussive for the microphone to handle even at a distance of ten to fifteen feet, with objects put in place to affect the acoustics in a way that would put less strain on the microphone.

    I would greatly, GREATLY appreciate some help on all things related to my specific questions in the thread, but also all things related to the entirety of recording concussive sounds such as firearms and explosives will be appreciated too. I have no problem creating them synthetically, but I need actual recordings for the stuff I am required to do.

  • avatar
    8 sounds
    4 posts


    I would also like to add to this that rather than the sounds distorting the microphone, the explosion is heard as a quick silence as the microphone peaks out completely, and a small reverberation after the explosion. I want to get it to sound as if it is exploding very close in proximity to the microphones position- I need the sharp, thunderous bang and boom of the explosives as well as the firearms, but I also need it to not peak out too much: I need to record the reverberation off of the environment completely.

  • avatar
    527 sounds
    651 posts


    What mics have you been using ?

    "I love deadlines. I like the whooshing sound they make as they fly by." Douglas Adams
  • avatar
    527 sounds
    651 posts


    I was involved in setting up a recording session to capture explosions and weapons some time ago.

    The venue was a quarry with a high cliff face to get plenty of reverb/echo. The mics used were mostly DPA cardioids with a couple of minatures as well as a Sennheiser shotgun (ME66 pointed at the cliff face).
    The mics were positioned from body worn (minature,during firing of shotgun and a couple of rifles) and every 3 metres to a distance of about 60m. As well as the firearms various on the floor percussive fireworks were used with the same mic placements.
    All recording was done at night (no birds) with subzero temperature (tight diaphragms) and no wind.

    I was not involved with post, but when I asked about the results the answer was very positive.

    Good luck, hope this helps.

    "I love deadlines. I like the whooshing sound they make as they fly by." Douglas Adams
  • avatar
    8 sounds
    4 posts


    Thank you all for the responses. After reading the replies, I pretty much have my questions answered (and I can relate somewhat to the actuall 'in person' sounds of artillery- i was at a demonstration a few years ago, and the sound is incredible- definitely something of a power that can not easily be recreated on a set of speakers.). My only lasting question is, as I move further away from the source, how would I go about (either in post production or in setup itself) keeping the feeling that it is happening closer than its actually being recorded? In other words, with distance between the source and microphone, how would I go about AVOIDING the feeling that the source is far away, even when it actually is?

  • avatar
    0 sounds
    31 posts


    I may be wrong as I am new to this but I am long time target shooter and I spent time in the Navy working on aircraft. What I would guess you would need to use some type of muted microphone for the initial blast and a un-muted mike the the sound a few MS later, which would be over driven to start with. Then process the two signals to make the shot sound sort of right. I think most of the movie gunshots and explosions are fake. From listening to 500 lb bombs go off they are more like a big thud if you are far enough away to to not get hurt. If you are close enough to hear the initial crack of the explosion you are too close. BTW a 20 mm M61A1 sounds like a big f-rt when it goes off it shoots so fast that all the explosions blend into one sound.

    Joe

  • avatar
    253 sounds
    86 posts


    mr16ga
    I may be wrong as I am new to this but I am long time target shooter and I spent time in the Navy working on aircraft. What I would guess you would need to use some type of muted microphone for the initial blast and a un-muted mike the the sound a few MS later, which would be over driven to start with. Then process the two signals to make the shot sound sort of right. I think most of the movie gunshots and explosions are fake. From listening to 500 lb bombs go off they are more like a big thud if you are far enough away to to not get hurt. If you are close enough to hear the initial crack of the explosion you are too close. BTW a 20 mm M61A1 sounds like a big f-rt when it goes off it shoots so fast that all the explosions blend into one sound.

    Sort of like that crazy canon that the A-10 planes have (or does the canon have the plane? lol)

    I've done a little firearm and fireworks recording and I've talked to a some of the dudes from Mythbusters audio team and a lot of users who record sound for video games (Which includes a lot of firearm recording). All the advise here is good. As was mentioned, as the sound get's louder, the ability to accurately capture a full bandwidth recording decreases. Explosive ordinance is going to be the most challenging and, in my opinion, it wouldn't even be worth attempting unless you had a professional quality mic and preamp. Even the bigger sounding guns (shotguns, sniper rifles, etc) are going to be really challenging unless you have a nice preamp and nice mics.

    The technique that was described wherein you set up multiple mics with some gained really low to accurately capture the loud part of the sound, and others gained higher to accurately capture the quieter parts, is one that I know has worked for me and some other people I've spoken with. the challenge with that setup is making sure that the signals are similar enough for it to not sound odd when you do your post crossfading and editing. the main guy I talked to who described this technique said that he actually used the same mics for each input and placed them in as close a position (distance from each other and distance to the source) as possible.

    A good preamp with a good limiter is indispensable for this application. The normal rule of limiting during recording still applies, which is: Limiters are designed to prevent clipping, NOT as dynamics tool for increasing the overall gain of lower amplitude signal (i.e. limiters are not compressors in terms of practical application). But a good limiter that doesn't obviously squash the levels when engaged is useful to prevent clipping for those sounds that just go over what you expected or adjusted for.

    If you find that the limiter is the only possible way to prevent clipping even with the input gain all the way down, then you need to use a pad. If you don't have a pad, and you're using dynamic mics, you might be able to run the mic into a line level input, depending on the connectors you have and the way the line level input is designed on your preamp. some recorders, like our (Sound Devices) 7-series, even give you the option to supply phantom power on line inputs, so you can do this with condenser mics as well. The feature of our recorder is used very often with users recording stuff like this.

    Basically, with these loud sounds, you're getting into an area where professional equipment doesn't just represent the difference between good sound and ok sound, but the difference between the ability to capture or not capture the sound accurately at all. My 2 cents. smile

    Nic Stage - Field recorder organism
  • avatar
    0 sounds
    31 posts


    Nic,

    Nice reply to the question about recording explosions.
    The A-10's gun is a 30mm GAU-7 as I recall. Much more powerful than an A-7E 20mm gun

    I got a question for you. Since all a loud sound is a change in air pressure can a sound that is loud enough damage a microphone? I would guess it could or does the mic just hit it's limit and stop moving?
    Joe

  • avatar
    253 sounds
    86 posts


    mr16ga
    Since all a loud sound is a change in air pressure can a sound that is loud enough damage a microphone? I would guess it could or does the mic just hit it's limit and stop moving?
    Joe
    Interesting question. The technical answer is "yes", but the practical answer is "no". I think it's so subjective because acoustic sound really is just a physical force, so technically a loud enough sound could physically harm anything. Like the initial pressure shock wave of a big bomb: That's technically a sound since it's just a moving compression and rarefaction in atmospheric pressure. But the SPL rating of all the condenser mics out there (Even the cheaper ones) is generally pretty high (Like standing next to a jet engine would be ok). Plus, the SPL rating of a mic isn't the level at which the capsule will become damaged, but maximum level at which the capsule can transduce acoustic sound accurately. Beyond a mic's SPL rating, the capsule will become unreliable in accurately transducing sound, but it won't necessarily break. The level at which a capsule would sustain actual damage is probably much higher than the stated SPL rating of the mic.

    Condensers are going to be more susceptible to damage from moisture or particulates on the diaphragms that could lead to impeading their motion.

    Ribbon mics are a special exception. They're fragile and if the ribbons touch, bad things can happen to the mic (If wiring is improper).

    Nic Stage - Field recorder organism

    9 posts