I just got hold of an Audix SCX1. So far I'm pretty impressed with its overall quality. I have a general question about usage of hypers versus shotgun mics. I understand why hypers are better indoor mics than shotguns, but why are shotgun mics better outdoor mics than hypers? Or are they? If I'm in a situation where I'm booming three feet away from someone delivering dialogue outdoors, what's the benefit of using a shotgun versus a hyper?
General question about hypers
- Thread starter jthabel
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Rick R
Veteran
"delivering dialogue outdoors, what's the benefit of using a shotgun versus a hyper?"
- The shotgun will sound better. If you need technical info, pick up "The Microphone Handbook" by John Eargle, this book technically covers almost everything one wants to know about how mics do what they do... it's not a cookbook though, and won't tell you which mic to use where.
- The shotgun will sound better. If you need technical info, pick up "The Microphone Handbook" by John Eargle, this book technically covers almost everything one wants to know about how mics do what they do... it's not a cookbook though, and won't tell you which mic to use where.
Allan Black
Veteran
+1 Mr. Eargles handbook is a great store of info, look on Amazon. And as Rick says, every situation will be different.
A good thing to do, if you've got the gear and the time. Set up your SCX1 on a boom together with a good shotgun, say an NTG-2, and record some voice tests.
Audix to the left camera track and G2 to the right. After you've recorded a store of these tests, male and female in quiet and noisy locations,
listen in post and note your impressions.
Eventually you'll be experienced and be able to go to a location and nail it together, every time.
Cheers.
A good thing to do, if you've got the gear and the time. Set up your SCX1 on a boom together with a good shotgun, say an NTG-2, and record some voice tests.
Audix to the left camera track and G2 to the right. After you've recorded a store of these tests, male and female in quiet and noisy locations,
listen in post and note your impressions.
Eventually you'll be experienced and be able to go to a location and nail it together, every time.
Cheers.
Noiz2
Sound Ninja
The shotgun doesn't sound "better" in that the quality of the recording is probably a bit better with the hyper, but there is much less rejection of what you don't want so it is "better" in that you are getting more of what you want and less of what you don't.
There is a lot of "life" going on outside that will get in the way of you getting dialog you can understand, and edit.
There is a lot of "life" going on outside that will get in the way of you getting dialog you can understand, and edit.
I agree with Scott that a shotgun won't necessarily sound "better", but it will reject more background noise than a hyper. There are many professional sound technicians who prefer the sound of a good hyper before that of shotguns, and will use hypers outside unless the background noise is just too loud.
paulears
Veteran
I think many people get confused by the 'correct' information we trot out, but we forget that context is important.
Think of a microphone as being a little like a zoom lens - in terms ONLY of field of view. Then consider the inverse square law. Halving the distance, quadruples the volume. The reason why shotguns can (but don't always) sound poorer indoors is because of aim and positioning. Using the zoom lens analogy, if the frame is filled with the subject, we can't see much of the background. If, however, the aim is only a little off, we see more of the background. This is what happens with shotguns indoors - the subject is not on axis, and gets attenuated, but the wall behind reflects lots of sound back to the mic. With a hyper, we have zoomed out, a little - so the subject can move a little without dropping off the main on-axis path. However - we need to consider distance too, because of the inverse square law, so a shotgun in close indoors can work very well - to get the same sound with a hyper means going in even closer.
I'm a firm believer in accurate aiming of shotguns, because they require it, where hypers can be easier because to a degree you just point them vaguely in the right direction!
Think of a microphone as being a little like a zoom lens - in terms ONLY of field of view. Then consider the inverse square law. Halving the distance, quadruples the volume. The reason why shotguns can (but don't always) sound poorer indoors is because of aim and positioning. Using the zoom lens analogy, if the frame is filled with the subject, we can't see much of the background. If, however, the aim is only a little off, we see more of the background. This is what happens with shotguns indoors - the subject is not on axis, and gets attenuated, but the wall behind reflects lots of sound back to the mic. With a hyper, we have zoomed out, a little - so the subject can move a little without dropping off the main on-axis path. However - we need to consider distance too, because of the inverse square law, so a shotgun in close indoors can work very well - to get the same sound with a hyper means going in even closer.
I'm a firm believer in accurate aiming of shotguns, because they require it, where hypers can be easier because to a degree you just point them vaguely in the right direction!
Steve House
Veteran
Paul, you're absolutely correct about the importance of proper aiming and positioning of a shotgun (though I would submit that the degree of aiming lee-way for best performance with a hyper is really no looser than with a 'gun) but you also need to remember that even when the mike is aimed properly, if there are a lot of short-term reflections from side walls or ceilings mixing with the direct sound in the 'gun's interference tube you will get comb filtering effects that can radically change the sound quality for the worse. Proper aim doesn't help that - moving to a non-reflective environment or switching to a mic that doesn't use an interference tube is the solution to that "coming from the bottom of a well" sound.
John Willett
Veteran
Paul is absolutely right in what he says.
But often people forget how a gun mic. is constructed and works.
A gun mic. is a "hyper" with an interference tube on the front. So - at low frequencies it will pick up the same as a "hyper" (probably up to 2kHz or more for the small on-camera ones). As the frequency rises it gets more and more directional.
The longer the interference tube, the lower the frequency that it starts to "focus" and the more directional it will be at higher frequencies.
Also - the interference tube can have a "comb-filter" effect off-axis so that a small angular difference can have a 10 or 20dB difference in sound level.
A "hyper" will have the same directivity as a gun mic. at the lower frequencies, but will stay the same at all frequencies and without any "comb-filter" effect.
But often people forget how a gun mic. is constructed and works.
A gun mic. is a "hyper" with an interference tube on the front. So - at low frequencies it will pick up the same as a "hyper" (probably up to 2kHz or more for the small on-camera ones). As the frequency rises it gets more and more directional.
The longer the interference tube, the lower the frequency that it starts to "focus" and the more directional it will be at higher frequencies.
Also - the interference tube can have a "comb-filter" effect off-axis so that a small angular difference can have a 10 or 20dB difference in sound level.
A "hyper" will have the same directivity as a gun mic. at the lower frequencies, but will stay the same at all frequencies and without any "comb-filter" effect.
This is all useful information, and thanks to everybody for their responses. Responding more specifically to Jema's answer above -- my big question is, if you're trying to get dialogue outdoors and you want to try to filter out as much background junk as you can to focus on an individual's dialogue (the same as you would indoors), then why is a shotgun typically the "go to" mic for outdoor booming? It seems to me like a hyper would be an even better choice in these situations, since you're dealing with even more peripheral noise outside than you are inside (cars, airplanes, nature sounds, etc).
Noiz2
Sound Ninja
The problem isn't sound from the sides, it's sound from the front bouncing off walls and then into the sides. When you are outdoors in the open you have essentially no bounce from objects (walls) so sound from the front is not bounced into the sides.
It's a highly simplified explanation but it's the essence of the problem.
The shotgun outside hyper inside "rule" makes some assumptions. Like that outside you will not be in a bouncy environment and inside you will.
A simpler "test" is clap your hands once and listen carefully. If you hear any slap-back the shotgun will probably have some issues. The shorter the slap-back the more likely you are to have problems.
A really dead room usually poses no problems for shotguns, and a really bouncy exterior say in an alley may cause all kinds of problems for the shotgun.
The shotgun will reject a lot more side sounds than a hyper which is why you want it outdoors where as you mentioned there is a lot more general sound. Indoors if the space is right a shotgun is also a good choice, but often the space is too bouncy or you just don't have the room to swing around a shotgun, so hyper is a better choice.
It's a highly simplified explanation but it's the essence of the problem.
The shotgun outside hyper inside "rule" makes some assumptions. Like that outside you will not be in a bouncy environment and inside you will.
A simpler "test" is clap your hands once and listen carefully. If you hear any slap-back the shotgun will probably have some issues. The shorter the slap-back the more likely you are to have problems.
A really dead room usually poses no problems for shotguns, and a really bouncy exterior say in an alley may cause all kinds of problems for the shotgun.
The shotgun will reject a lot more side sounds than a hyper which is why you want it outdoors where as you mentioned there is a lot more general sound. Indoors if the space is right a shotgun is also a good choice, but often the space is too bouncy or you just don't have the room to swing around a shotgun, so hyper is a better choice.
Scott gave the same answer I would have: The shotgun rejects more than a hyper but can sound weird when there are a lot of reflective surfaces nearby, which is why it's usually the go to mic for outdoors (few reflections), while a hyper is preferred indoors (lots of reflections).