audio rumble noise with Sony HXR-NX30U

[Peter Siamidis]

Wasn't sure where to post this, but this seems like the closet forum, mods please move if it's in the wrong place.

I've been having issues over the years using external mic's on cameras, always with excess noise captured by the mic. I've returned many mics/cameras over the years because of this so this time instead I tried ordering an all in one figuring that would work better, which is the Sony HXR-NX30U. I received it yesterday, I figured since they included a mic that it's all designed to work together well and I'd get no noise. Alas I'm still hearing noise, so at this point I figure it must be me but I just can't figure out for the life of me how to get clean audio from this thing.

For tripod or documentary type purpose where the camera doesn't move, the mic is fine. But most of my filming is random run and gun, so I'm holding the camera and moving around. In this situation I'm constantly hearing some kind of low frequency rumbling noise. I've tried holding the camera by it's handle while recording, and using a rig I have but I still hear that noise. I put a short recording of it here at this link:

http://www.realitystudiollc.com/audioissue.mp4

Video quality is low to make the file small, but you can hear the issue in the audio. There was no wind at all, that rumbling you hear just seems to be coming from, well, I don't really know where. Even when I film indoors it's the same, anytime the camera is moved you hear that rumbling noise which makes it totally useless for my purposes. I tried setting "low cut" on the mic but that didn't solve it, tried manual mic levels and that didn't work either. How do you guys get clean audio from external mics? I've always just used the internal camera mics because after trying countless external mics I just could never get noise free audio so I gave up, but I figure there must be a way. The stuff I film is like reality shows basically, so one camera moving around and no separate audio guy holding a boom mike, it all must be self contained on the video gear which is why I was hoping the NX30U would finally solve my issue but it didn't. Anyways I'm going to keep playing with the camera, but I'm grateful for any suggestions!

[Matt Sharp]

I've done a lot of work with my NX70U that has the same mic/audio handle and haven't experienced that. Running through plastic curtains and other stuff that rubs and bumps the mic, still comes out without that noise.

Only thing I can think of is that you have a defective mic. Might be some part loose inside that's bumping around as you move.

[Bryan Scott]

Sounds like your mic is picking up noise from the camera body. I would try and isolate whats happening. For instance grab a headset so you can hear whats going on real time. Turn the camera on, doesn't matter if its on a table top or a tripod. Then touch and lightly tap the camera body and see if the mic is picking that up.
The ECM-XM1's boom mic is the same as the one I have on my camera. I use one channel with the boom mic and the second with my wireless mic. If the ECM-XM1 isn't connected properly the audio defaults to the onboard mic on the camera and if thats the case here maybe you're getting sound from the camera body's own internal mic.

[Peter Siamidis]

Hi guys, ok I tried your suggestion Bryan, the mic definitely seems to be picking up even the slightest touch on the camera or the camera rig. Here's a pic of the mic mount on the camera:

http://realitystudiollc.com/images/nx30/6.jpg

Those 8 round things are rubber grips that hold the mic tightly, is it possible those are transmitting that rumble I'm hearing? Here's a pic of the entire camera with the mic mount:

http://realitystudiollc.com/images/nx30/1.jpg

...and here's a pic on a small rig that I use:

http://realitystudiollc.com/images/nx30/7.jpg

So when listening with headphones, even when I run a finger along the camera rig that I use I hear it being picked up by the mic. I have the mic setup as the manual suggests, it says set att at 10db for that mic, and put it in the mount with the mic model numbers displayed on top. I played with some of its settings, trying auto mic level and setting it manually, as well as trying the "low cut" setting that it has but in every case I still hear audio noise. Unfortunately for my needs I can't use a boom mike or anything like that, it's all for reality style filming by one person. So I guess I need a better rig or mic mount to isolate it more?

[Mike Beckett]

I've got exactly the same XLR block on my NX70 (and mic, I presume), and I don't have too many problems with handling noise, but it takes a lot of care.

These are my thoughts, coming from an NX70, not an NX30. It's still possible that there's a fault with your mic, without handling it myself I can't tell.

It's been exactly the same with my previous three cameras (Sony and Panasonic) with similar mic clips. It's way too easy to transmit handling noise to the microphone.

Running fingers along the camera rig or camera body will create vibrations, and transmit it to the microphone. I'd need to see exactly what's happening to the camera to work out what the noise is.

Also, with just the stock foam cover on the mic, it's very susceptible to wind noise - just panning or moving the camera quickly will create rumble as well.

To stop handling noise transmitting to the mic, the best thing is to get the mic mounted in a proper suspension that isolates the mic from the camera body, like a Rycote Lyre-type mounting (other brands exist, but, bluntly, they aren't as good - I've wasted money on them).

[Les Wilson]

It sounds to me like handling noise.... noise that travels through the rig to the mic. Is it possible you have the shotgun mount too tight? You want the shotgun to be suspended in the rubber. It will wobble a little but only within the suspension.... and not hit the hard mount. Rubbing the cable can also cause handling noise.

[Bryan Scott]

Originally Posted by Peter Siamidis

Hi guys, ok I tried your suggestion Bryan, the mic definitely seems to be picking up even the slightest touch on the camera or the camera rig.

Generally there is pretty good sound isolation between the ECM-XM1's boom mic and the rest of the rig.

You've got me wondering if the boom mic is engaged? When you run your fingers across the body also see if the boom mic is working by running your finger across the boom mic itself.

[Peter Siamidis]

Originally Posted by Mike Beckett

To stop handling noise transmitting to the mic, the best thing is to get the mic mounted in a proper suspension that isolates the mic from the camera body, like a Rycote Lyre-type mounting (other brands exist, but, bluntly, they aren't as good - I've wasted money on them).

Ok I think I'll have to look into that, and perhaps a better quality rig as well as mine is fairly cheap. I just did one more test which was interesting, rather than hold the camera instead I suspended it from a small rope and walked around my entire back yard filming, so lots of walking, turning, etc, and my hand was never near the camera. That footage was almost perfectly noise free, no rumbling, nothing at all. So that does indeed seem to tell me that the shotgun mic is picking up even the slightest movements from my fingers when I'm holding the camera.

Originally Posted by Les Wilson

It sounds to me like handling noise.... noise that travels through the rig to the mic. Is it possible you have the shotgun mount too tight? You want the shotgun to be suspended in the rubber. It will wobble a little but only within the suspension.... and not hit the hard mount. Rubbing the cable can also cause handling noise.

Well this camera model doesn't have a tighness setting, it's a single clamp that holds the mic in place only one way, it just snaps closed. It seems to be suspended in there ok, the rubber feet keep it away from the hard plastic parts, theres just a little wiggle to the mic in the holder.

Originally Posted by Bryan Scott

Generally there is pretty good sound isolation between the ECM-XM1's boom mic and the rest of the rig.

You've got me wondering if the boom mic is engaged? When you run your fingers across the body also see if the boom mic is working by running your finger across the boom mic itself.

Yeah the external shotgun mic is on, I don't get any rumble when using the camera's internal built in mic, only when using the on camera shotgun mic that's included with it. From the tests I did today it just seems like both my rig and the camera itself are very sensitive to any finger movement and it comes thru as rumble via that shotgun mic. My rig is very cheap, maybe I need to find a better quality one that more isolates the rig from the camera. Even when just using the camera itself with no rig, holding it like shown in all the marketing pics, your pinky finger ends up resting on the little nubbin that hooks to the active shoe that provides phantom power to the mic and even the slightest movement of my pinky finger woul get picked up as rumble by the shotgun mic, irregardless of what audio settings i used (auto, variable gain, etc).

Overall I'm still very happy with this camera though. It's definitely a step up fromt he 560v's that I've been using. I think what I'll do for now is use the shotgun mic for all tripod style footage that I record, because the audio quality from that mic when on tripod is actually really good. For the run and gun stuff I'll stick with the internal built in mic that is lesser quality but doesn't have the rumble issue, at least until I can find a shock mount or rig that is able to isolate the shotgun mic from finger movements.