Sony HXR-NX30 Noise issue with XLR

[Ken Estes]

Hi,

There is always a low buzzing rumble when using the XLR unit.
It's an inconsistent static'y buzzy rumble.
I'm hoping someone here can shed some light on this issue.

I've just received my 2nd new Sony HXR-NX30.
I'm sending the 1st back on an RMA, because the sound was quite distracting.
and the 2nd camera exhibits the same issue, to a lesser degree. I'm stumped.

With the XLR unit, and the included shotgun mic (with incl. windscreen) on CH1,
the noise is primarily in the unused CH2, but is underlying in CH1 as well.

This occurs with no contact with the camera, on tripod, in a sound-baffled padded room, with no air movement.

Settings are:
Rec Select: CH1 (or CH1+CH2 wherein the noise is mixed into both channels)
CH1 10db
Man set to 5
Low Cut Off
Mic+48

Settings for CH2 don't seem to matter; Attenuation, Line, Mic, Mic+48, Low Cut, etc.

Noise is equally audible through monitor headphones, and on recorded files.
Noise is not present using the internal mics, only with the XLR unit.

Changing Low Cut on CH1 to on significantly cuts down the low end components of the noise, but doesn't eliminate it.

If I add another shotgun to CH2, the noise is just slightly lower, bat all the above still applies.

Are other HXR-NX30 owners experiencing this?
Is there a workaround, or something obvious that I'm missing?
Do I have to try returning unit 2, too?

Thanks for any input.
Ken

[Ken Estes]

I've been able to get a sample file webhosted.
It's a 2.5mb MP3 of a test for this noise on a tripod in a padded room with no air movement.

http://www.art-ajar.com/HXR/00004%20...tracted_01.mp3

Any feedback welcome.
Thanks.

[Ron Evans]

Have you tried setting the microphone level in the menu setting to low. That seems to work for me.

Ron Evans

[Ken Estes]

Hi Ron,
Thanks for your reply.

I'm thinking that you're referring to the 'Micref Level' setting? (Operating Manual p.74) ?

I hadn't tried that, possibly I falsely assumed that it affected the Internal Mics only, and that the Low setting states "(This setting is not suitable for recording conversations.)"
I expect to record conversations amongst other things.
I just tried it. Thanks for the suggestion.

I'm doing extensive testing.

So far,
* Micref setting appears to have no or minimal impact on the noise. (I'll test further)
* Attaching or removal of monitor headphones has no impact.
* Attenuation settings just move the noise and signal up and down the scale, but the S/N appears unchanged by the movement.
* Low Cut filter has the most impact.

Specs for the included shotgun mic ECM-XM1 show an S/N of '78db, typical' but I'm not seeing anything like that in my admittedly non-pro tests.

One curious discovery so far, between the 2 ECM-XM1's I have in-house at the moment, one is about 5db more sensitive to signal and the noise, but the spread between the mics drops to 2db with Low Cut on. To test for this, I have swapped them between channels a couple of times with no other setting changes. I'm using PremiereProCS6 Level Meters to evaluate this.

I am working through various combinations of settings to find the best balance.

So Ron,
can I assume that you too have this kind of noise in your NX30?

[Ron Evans]

The manual says to set the unused input to line level and it seems to work on my unit.

Ron

[Ken Estes]

Thanks Ron. Yes, I've tried that with no change.

That doesn't make a difference for me, alas.

The most useful setting is Low Cut, but it comes with the thinner sounding track.

Still trying out variations of settings.

Any other thoughts?

[Pierre-Yves Beaulieu]

Hi Ken, had you found a solution for the NX-30 rumbling issue?
I also bought the NX-30 and had a first shoot last night, and got an issue similar to the one you experienced, however I think the rumbling was lower than the clip you just posted. I had filmed in Dolby, and tonight I have another shoot so I'll try out Linear PCM and see what happens, in case the Dolby compression might have an impact.
Please let me know if you found the fix, thanks!

[Ken Estes]

Bonjour Pierre,

I returned the 1st NX-30 (thanks to B+H Customer Service) and got another.
It has the same issues but at a much lower level, usually.

I have now tested it with the included Sony ECM-XM1, an Audio Technica AT899, and a new Sennheiser MKE600.
I only use Linear PCM.

It helps to use the Sony XLR Low Cut on Ch1, and if I the lower the gain, the more present the noise is.

I had gotten the MKE600 hoping to improve on the audio with the intent of running the ECM-XM1 on CH2 with a lower gain just as a 'clipping insurance' track. But, I actually like the MKE600 sound so much better, I'm trying out running it on CH1 with the channels summed (CH1+CH2) and the gain on CH2 lower for the clipping thing.

So far, that's my best combo,
but I still hear the noise, and some fuzzy static intermittently. I haven't yet been able to pin it down.
It mainly in quieter shooting locations, but not entirely.

I have a shoot tomorrow, and one next weekend. If I can't get clean enough sound, I'm thinking of sending the XLR unit to Sony Pro Repair, though I dread the thought of that.

I hope some of this helps you.
Let's keep communicating till we get it sorted out.

Cheers,
À bientôt,
Ken

[Pierre-Yves Beaulieu]

I am using the provided mic in Channel 1 and a Sennheiser wireless kit in Channel 2, both channels are experiencing the issue to varying degree. So I know it has nothing to do with the mics. I had run tests when I got the camera with a friend who happens to be a soundman, and I can confirm the provided mic works very well.
I need to run more tests but the rumbling seems to vary from time to time. Yesterday I tried plugging it at home to troubleshoot but I was getting a clear sound, or the issue was barely perceptible.
I will try to see how to reduce the rumbling as much as possible as you suggest, and will let you know what settings work best for me. I also really want to avoid returning the XLR unit, especially after hearing that you had already returned it and got the issue again...
Cheers

[Ken Estes]

Hi Pierre,

I wasn't completely clear.
I returned the whole 1st camera purchase to B+H for a refund. That's the one with the louder noise.

At that time, I bought a 2nd camera which is what I am using now.
I have not returned anything for repair, yet.

I too find that sometimes the sound is clear, and sometimes noisy, but I haven't been able to predict a pattern.

K

[Pierre-Yves Beaulieu]

Hey Ken,
Just ran a few tests using the shotgun mic and my wireless receiver.
My findings seem to exclude a contact issue with the hotshoe interface connection.

I set the gain to 0 and turned off the low cut, and although no sound was coming from the mic I would get the noise sound isolated and pretty clear. This means that the noise appears between the gain and the low cut, since the low cut diminishes it, and it would be independent from the gain. So one might want to maximize the gain to minimize the impact of the noise.

I unplugged both mics and got no noise.
I plugged only in Channel 1 either XLR devices and got the noise pretty clearly.
I plugged only in Channel 2 either XLR devices and didn't get any noise.

Not sure if it's the same on your end, but this means I could record properly using only Channel 2 and one device. Quite nice but I need the wireless lavallier and the shotgun on two tracks for the documentary project I am currently working on.

I am curious, had you run a test using a battery-powered mic instead of phantom power? I don't have one handy.
Thanks!

[Pierre-Yves Beaulieu]

Also, it seems that reducing the Att level on channel 1 highly reduces the noise on channel 1, and also on channel 2.
So tonight I will try to shoot again in the same setup as yesterday with Att set to -20db for channel 1.

[Ken Estes]

I'll try to replicate your results as well.

Thanks for the update.

[Ron Evans]

Did another test of mine too. With att at 10db or 20 db on channel one a get a little noise with either just channel 1 selected or channel 1 the source for channel 1 and channel 2. Channel 1 set for auto gain , channel 2 set at 5. At 0 db att. the noise was less with gain on auto. Channel 2 is quieter than channel 1. Noise in the headphone monitoring doesn't help. I recorded short clips and placed back in Vegas, opened in Sound Forge to really see how much noise there was. It was a lot less than when monitoring with headphones. My playback is through Yamaha NS10M monitors so if there is noise I will hear it !!! Did another test with the XM1 mics one that came with the NX30 the other from my NX5U. with att set at 0 on both channels noise was acceptable for me but still quieter on channel 2. Will try some more variations.

I have my trim set at 0db for the XLR inputs on my NX5U for the XM1 mics. Noise level is more like channel 2 on the NX30.

Ron Evans

[Ken Estes]

With either the XM1 or the MKE600 in Ch1, the noise is present;
it's significantly worse with the XM1 in Ch1 than the 600 in Ch1.

The noise is a greater part of signal with XM1 CH1 ATT @20db, which makes for a noisy/fuzzy sound - completely unusable.

The noise is worse through the headphones, and has another component to the noise there, making it seem that the headphones noise is another, compounding issue.

So far, my test with only the 600 in CH2 had little noise.

I'll test further.
I'll also re-try my +48v vs Batt power tests, which didn't seem to matter before.