audio rumble noise with Sony HXR-NX30U

The problem with auto level is that when the speaker pauses, the auto gain control ramps up the gain to max 'looking' for a non-existent signal. This means it's recording all the background noises as loud as it can get them, thinking they are the intended signal. Then when the speaker starts to talk once again, he comes in very hot until the gain control has time to turn itself back down again.

Yeah that's true, although sometimes I actually leave the camera with the film subject and they do their own thing alone without anyone there to monitor stuff like audio levels, etc. So I'll still use the camera on full auto for those types of videos, and I'll set audio level myself when I'm there and when what's being filmed is a bit more predictable in it's audio nature.
 
Every reality show has a sound crew. The type of show will dictate the equipment used. I actually sold all the production sound gear to the production company that was doing Deadliest Catch for its first season. Mostly wireless at that time, but they did get a couple of boom poles. That type of show didn't really accomodate boom ops, so they pretty much went wireless the whole time. They confirmed it when they bought gear for the second season (most of the gear is trashed by the end of the shooting season). Shows like COPS and Survivor use a combination of wireless and booms. I know this because both of those shows use a ton of our boom poles, and after each season, they send them in for refurbishing. Those shows are really tough on gear. There is inevitably sand and salt water residue on the boom poles from Survivor, and the boom poles on COPS sometimes get used as defensive weapons...no joke. I cut sound effects on the second season of Hell's Kitchen, and that show was mostly wireless mics with some plant mics strategically placed throughout the kitchen. When I was cutting sound on Fear Factor, it was all wireless. The Amazing Race is a mix. None of these shows used on camera microphones for their main source of audio.
 
Every reality show has a sound crew. The type of show will dictate the equipment used. I actually sold all the production sound gear to the production company that was doing Deadliest Catch for its first season. Mostly wireless at that time, but they did get a couple of boom poles. That type of show didn't really accomodate boom ops, so they pretty much went wireless the whole time. They confirmed it when they bought gear for the second season (most of the gear is trashed by the end of the shooting season). Shows like COPS and Survivor use a combination of wireless and booms. I know this because both of those shows use a ton of our boom poles, and after each season, they send them in for refurbishing. Those shows are really tough on gear. There is inevitably sand and salt water residue on the boom poles from Survivor, and the boom poles on COPS sometimes get used as defensive weapons...no joke. I cut sound effects on the second season of Hell's Kitchen, and that show was mostly wireless mics with some plant mics strategically placed throughout the kitchen. When I was cutting sound on Fear Factor, it was all wireless. The Amazing Race is a mix. None of these shows used on camera microphones for their main source of audio.

Thanks for that info. When amateurs like me try to use a camera shotgun mic for audio and just can't get it noise free, then I see these tv shows and think they are managing to do it with on board mic for audio, it can get frustrating making me think what the heck am I doing wrong, why can't I get clear audio from this thing? At least now I know it's because they don't do audio that way. It all makes much more sense to me now, I'm glad I posted here! I can still use the on board shotgun mic for ~66% of my work which is cool, for the rest I'll make do with the camera's internal mic for now as many of those other solutions like wireless, boom mics, etc, won't work for some of my stuff due to it's odd nature. I'll probablh experiment some more with new rigs as well.
 
It's a simple fact of physics that if any mic is more than 1-3 feet away from its source you may have problems, if you stick to that you have a good chance of getting decent location sound for most subjects.

So if you are doing run and gun with a camera mic the chances are minimal of getting anything other than basic ambient sound.

But I have done quick grabbed interviews with a camera mic but it has been within that 1-3 foot distance.
 
Thanks for that info. When amateurs like me try to use a camera shotgun mic for audio and just can't get it noise free, then I see these tv shows and think they are managing to do it with on board mic for audio, it can get frustrating making me think what the heck am I doing wrong, why can't I get clear audio from this thing? At least now I know it's because they don't do audio that way. It all makes much more sense to me now, I'm glad I posted here! I can still use the on board shotgun mic for ~66% of my work which is cool, for the rest I'll make do with the camera's internal mic for now as many of those other solutions like wireless, boom mics, etc, won't work for some of my stuff due to it's odd nature. I'll probablh experiment some more with new rigs as well.
I have to point out that a shotgun mounted on-camera might well be a better quality mic than the internals provided by the camera manufacturer, it's still in just as lousy a position for quality sound pickup as are the internal mics. You have to get rid of the idea that a shotgun reaches out to capture distant sounds, magnifying it like a telephoto lens magnifies the image. Shotguns simply don't do that - they no more sensitive to distant sounds than are any other type of mic. What shotguns have is REDUCED sensitivity to sounds arriving from the sides and rear so as to help pick out the desired sound from the surrounding ambiance. That buys you a little working elbow room, but not much. A 'gun being used for dialog needs to me about 20 inches away from the person speaking and aimed within a an imaginary circle of about 10 inches in diameter centered on the speaker's mouth. Any further away and the sound quality starts to drop dramatically. This means that the position you'll usually want to place the camera in order to get good images is the last place you'll want the mic in order to get good sound. This applies whether you're talking about the internal mics or a high quality shotgun mounted on the camera or held someplace close to it.
 
Ah ok understood. I have another question but it means revealing the nature of my amateur work, hopefully that won't scare posters away. I run a few amateur websites, all adult themed, for two of them I can make the on board shotgun mic work fine since they are tripod filmed and meet the criteria you guys have listed. The third site which also happens to be the big money maker site is a different beast entirely and has a whole host of limits. Without getting into details I can say that for that site it's impossible to have any crew on the set aside from me because the people involved will just get spooked (they are all amateurs), it has to look as little as possible like a filming set basically to keep everyone comfortable and natural, meaning I'm the only person there behind the camera so boom mics can't be used as there is no one to hold one. I can't use wireless mics because, well, often there is no where to put them. I can't stategically position mics either because filming sometimes moves around quite a bit (it's all unscripted) and who knows where I'll end up, could be inside, outside, upstairs, etc. So that's why I've been sticking with the internal mic on the hd handycams I use for this site (started with an HDR-HC3 in 2006, now using a 560v) because as primitive as it sounds it actually works in all my scenarios and it lets me be very unobstrusive, I can basically dissapear and not be noticed during filming, something that isn't possible with lots of crew around or boom mics hovering in the air. The small cameras also let me hold them in some potentially strange positions for lengthy periods of time, again something not possible with larger cameras. I realize my situation is kidna unique, but that's why it's been hard for me to find a good solution to improve my audio.

I do realize the quality of my audio is weak though which is why I've been eyeing better mics for a long time now, but I just haven't been able to make them work for my unique needs. In this kind of scenario, is there any kind of on camera xlr mic that would work on a small camera? Maybe I need an omnidirectional mic to pic up a bit more of an audio cone than the narrow cone of a shotgun mic? Maybe a less sensitive mic so that it doesn't pic up my camera handling noise? My current audio basically sounds kinda hollow and it does pic up sounds from 360 degrees all around, what would work better is a more narrow audio cone to at least focus the audio a little more, fuller sound quality, no camera handling noise, all from a camera mounted mic. Is that even possible? I can get away with the weaker audio because my stuff is amateur but still if I could improve my audio quality then bonus.
 
A common cause of 'hollow' sound is the mic being too far from the subject. This is the case regardless of the polar pattern of the mic - the optimum working distance is a bit greater for a shotgun compared to an omni, for example (though not as much as you might think), but the physics of acoustics is the same for all. BTW, you mentioned you thought you might need an omni mic - take note that the optimum working distance for an omni is only about 8 inches from the speaker's mouth.
 
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Ah ok understood. I run a few amateur websites, all adult themed,

Forgive me...but in this situation, is audio that big of a concern?

If you have to go camera mounted for you mic, then maybe get a nicer short shotgun and mount it in a shock mount on the shoe of the camera. That may product better results, but you'll need a mic pre with the proper output signal for your camera's audio input.
 
I'm the only person there behind the camera so boom mics can't be used as there is no one to hold one.
I can't use wireless mics because, well, often there is no where to put them.
I can't stategically position mics either because filming sometimes moves around quite a bit (it's all unscripted)
You have painted yourself right into the corner with no way out. Sorry, nobody can break the basic laws of physics and acoustics. No matter what the genre.

is there any kind of on camera xlr mic that would work on a small camera?
No, and not on a big camera, either.

Maybe I need an omnidirectional mic to pic up a bit more of an audio cone than the narrow cone of a shotgun mic?
No. You said you are already using an omnidirectional mic (or a mic that "does pic up sounds from 360 degrees all around"). The wider the coverage the MORE extraneous noise and the worse the dialog will be.

Maybe a less sensitive mic so that it doesn't pic up my camera handling noise?
No. Because then it will pick up less dialog as well. If you want to pursue this, you must move the microphone AWAY from the camera noise.

My current audio basically sounds kinda hollow and it does pic up sounds from 360 degrees all around,
More likely it sounds hollow simply because it is too far away.

what would work better is a more narrow audio cone to at least focus the audio a little more, fuller sound quality, no camera handling noise, all from a camera mounted mic. Is that even possible?
Not really. When they shoot this kind of thing in Hollywood, the actors go into the studio afterwards and re-record all the dialog nice and clean (ADR = Automated Dialog Replacement, aka "dubbing")

If you are watching a movie and you can't see how they could get the microphone close enough to get that kind of good sound, you can probably guess that what you are hearing is NOT what was recorded while they were shooting the picture you are watching. There are no magic microphones. Only behind the scenes hard work to create good audio. It cannot be achieved by your casual scenario.
 
Forgive me...but in this situation, is audio that big of a concern?

Well you know I'm always interested in increasing production values if I can. I started that one site for the heck of it and it just took off to where it makes a pile of money now and gets 50k+ hits per day, but my basic filming style and gear really hasn't changed much for years, I'm still using hd handycams and their built in mics. So I've been evaluating things lately and identified audio as my weakest link quality wise, so I started looking into what I can do about it. Alas it appears to be not very much :(


You have painted yourself right into the corner with no way out. Sorry, nobody can break the basic laws of physics and acoustics. No matter what the genre.
...
If you are watching a movie and you can't see how they could get the microphone close enough to get that kind of good sound, you can probably guess that what you are hearing is NOT what was recorded while they were shooting the picture you are watching. There are no magic microphones. Only behind the scenes hard work to create good audio. It cannot be achieved by your casual scenario.

Thanks again for all the info, you've saved me lots of time and hassle. I think for now I'll just work with what I have then for that one site, basically stick with the internal mic and that's it. I can't change the design of the site so not much choice there. The internal mic on the nv30 does give very different results than on my 560v's, I guess because the 560v captures in 5.1 whereas the nv30's is just stereo. I'll have to test it out and see how much of an improvement it is. It looks like the nv30's internal mic is more focussed towards the direction of filming whereas the 560v's is omni directional, so maybe the nv30's internal will still give me some improvement over what I have now. In the meantime the shotgun mic works great for my other two sites though which are much more predictable, the audio quality from that shotgun mic is really good to my ears anyways. So I still love the camera and thinking of getting a second :)

Thanks again guys for all the help!
 
Serious dialog is recorded in MONO. Stereo just diffuses the sound, and "5.1" is a disaster. "5.1" recording on a consumer camcorder is a cheap gimmick and is highly unlikely to give you any usable dialog recording. At best it might be useful for recording ambient sound effects. True 5.1 theatrical sound is synthesized in the mixing studio. Typically from monaural or sometimes stereo sources. Actually recording "5.1" in the field is an experimental rarity.
 
One thing you might try is to carry a set of moving blankets and some C-stands to to make improvized acoustical gobos to kill or minimize the echo of any room, this might help out the hollow-ness of a room.

Cheers
 
Here's a few pics I just took:

http://realitystudiollc.com/images/nx30/1.jpg
http://realitystudiollc.com/images/nx30/2.jpg
http://realitystudiollc.com/images/nx30/3.jpg
http://realitystudiollc.com/images/nx30/4.jpg
http://realitystudiollc.com/images/nx30/5.jpg

The way the mic is one this camera there is really only one way to mount it, theres a concave part of the back of the mic that has to go into the holder and it just fits. I double checked in the instructions and it's what it says as well. It also mentions that the mic name should be face up so I did that too.




I was wondering about that, I'm relatively new to the audio side of things so perhaps I have uinrealistic expectations. What I need is basically like on tv reality shows, stuff like Swamp People, Storage Wars, etc. On those types of shows there isn't a separate audio guy holding a boom mic, etc, it's basically one guy with one camera with the one person he is filming and that's it correct? Often there's just no room for anyone else, even on shows like Dirty Jobs when the camera guy puts himself in tight spaces with the shows host.

Here's an example, once on Storage Wars the camera guy was filming Dave Hester while in the car, it was a two seater car so it was just Dave and the camera guy. As Dave stopped and got out of the car he dropped an item and broke it. The camera guy in the passenger seat, being he was the only person there filming, got out quickly, ran out over to the drivers side of the car and basically didn't miss a beat, he filmed the whole thing by hilmself with that one camera and the audio was great. You could see his fingers briefly in front of the lense as he was running out I think because he slapped on a filter when he got out of the car as the video was overexposed briefly once he got out, but that's about it. His audio wasn't filled with noise it actually sounded good. That's the kind of stuff I need the camera for, one person, one camera, unscripted scenarios where anything can happen. Is it possible I just need far more expensive gear to get good audio with that, and that my little NX30 is really just meant to be on a tripod when using it's external mic? I got all excited when I saw the NX30 because it looked like exactly what I needed, really good stability control is hugely important to me because of the unscripted nature of what I film, and with that standard external mic I thought I was all set! But I'm starting to wonder if that external mic is really only intended to be used while the camera is mounted on a tripod, and the internal mic should be used when using it run & gun.
I realize this post has been here for awhile and you might have solved your problem, but I'd like to expound upon your very interesting comment about this camera having done so much to address motion control in the camera's video section. I have not used this camera yet, but the samples posted online are indeed impressive. However, Sony makes no claim and I really doubt they gave it a second thought, about any such improvements in audio. With rare exceptions, audio is an afterthought. As another user posted, almost all audio done in broadcast television is separately captured. As I'm the rare audiophile in video, I am appalled at producers who justly demand the best video shots, and then take what comes as far as audio. I'm equally impressed when I experience a documentary or drama where equal attention is given the sound track. To your problem, I would suggest getting a third-party mic mount and seeing if it can be affixed. Mounts from companies such as Rycote have significantly improved the isolation of mics in recent times. The other thing you might investigate is a decent wind reduction device. The best ones I've used are acoustically transparent balls that fit tighly over the mic. Some of what you describe (I wasn't able to load your samples) would be wind rumble. Even if there's no wind sometimes walking creates this sound.
 
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Even if there's no wind sometimes walking creates this sound.

Exactly right. Wind noise is caused by air moving across the mic's element. It can happen two ways -- either the mic is stationary and the air moves (wind), or the mic moves through the air (camera/mic movement). Often people don't think of this when considering whether or not they need wind protection for their mic.
 
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