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Old December 27th, 2007, 04:33 PM   #1
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Canon GL2 and Rode NTG2 Hum Problems

Hello!

I have been using a Canon GL2 and recently upgraded my sound to the Rode NTG-2 with the beachtek adaptor. Every since I did this upgrade, there has been a LOUD HUM which is only audible if you listen to the videos with good quality speakers - you can hear it here:

http://www.youtube.com/watch?v=Ax2jjGh4o6A

The hum is less audible when listening to the videos on internal computer speakers. You can't hear the hum through the Sony MDR7506 headphones when filming. You can only hear it when you digitize it and play it back.

I only recently got good speakers and started hearing it myself - it is awful. I have been testing everything I can to figure out what is causing this hum. Have anyone experienced this before?

Is it the camera, the mike, the Beachtek, the cords, the computer??

The on camera mike has always worked fine in the past and needless to say, I won't be using the Rodes until I can resolve this.

Even though it RUINED the sound in 8 videos (I am going in to resolve it in post) at least I learned a good lesson, good speakers ARE worth it!

Any help is SO appreciated!

THANKS!

PS The Beachtek manual says to make sure the camera is turned to MIC and I am not sure what this means. Anyone know how to do this on a Canon GL2?
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Old December 27th, 2007, 06:11 PM   #2
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Hummmmmmm......

Eva,

I had a similar problem when I used an AC-to-DC converter to power my camcorder. The mic cable picked up a 60 Hz hum. Your hum sounds a bit higher pitched (maybe 120 Hz?). Anyhow, if you were using any sort of AC-to-CD adapter, try switching to battery operation and see if the hum goes away.
BTW, since you're using an XLR adapter and an XLR mic, the cable is probably balanced, so it wouldn't be as likely to pick up hum, but there is that short length of unbalanced cable going from the adapter to the miniplug input on the camcorder. Don't know if that short length can be shielded somehow.

Good luck,
Ken

P.S. -- Some camcorders (and other devices) have inputs which can take a mic-level voltage or a line-level voltage. If your camcorder could do that, it would have a LINE/MIC switch.
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Old December 27th, 2007, 06:15 PM   #3
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Eva, I am a newbie in sound myself, but have been learning how to best upgrade the audio on my GL2. In reading through the very educational posts here, I saw several references to people getting a hum using a Beachtek. I would recommend a search through the threads for references to this might reveal similar issue to yours. I recall seeing some very specific suggestions for reducing / eliminating the interference

I have found this site to be a fantastic resource, and VERY helpful.

Last edited by Bill Spearman; December 27th, 2007 at 07:07 PM.
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Old December 28th, 2007, 02:55 AM   #4
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Hi Eva:

I gave a listen through most of the video in your link and I notice the hum is consistent in all of the cuts in your piece. Nice piece, by the way. I'd expect it's not likely coming in during the recording of the camera original but rather creeping in somewhere in your post production workflow. If the fault was your mic and Beach I'd expect it vary in level from shot to shot or even drop out altogether for some shots. Fast way to check that would be to playback in the camera itself one of the camera original tapes of a scene where the hum's most apparent in the final video, use the camera's A/V out to listen to it on a good monitor system (and listen both with the camera on its AC adapter if you've used one and also on battery), and see if the hum's there. If it's not, then your camera audio isn't at fault and you need to look later in the chain. So what's your postproduction hardware and workflow?
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Old December 28th, 2007, 03:59 AM   #5
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NO luck

Thanks for your suggestions.

Steve! I got so excited thinking that you had found the answer but no, the hum is in the tape I think. I tried listening to the audio tests I have been doing with the Canon GL2 plugged directly into the fancy new Studiophile DX4 speakers I bought and the hum is still there. Also, the audio levels are oddly low.

I tried digitizing video from my recent audio tests using the Canon GL2 instead of my normal "deck," a Panasonic PV GS200. Both yielded the same result: the sound from audio recorded with my on camera Canon mike is fine and audio recorded using the Beacktek and the Rode NTG-2 is infected with this high pitched hum.

Postproduction is Final Cut Pro 5 and a G5. What baffles me is that the on camera mike records and digitizes fine!?

Bill, agreed, it is a great site. I am also new and found only one post referring to the hum associated with the Beacktek, the Canon GL2 and Rode NTG-2 Combo. Am I looking in the wrong places?

Ken, I am not using an ACDC adaptor. And The Line/Mic switch is on the Beachtek which I guess is my adaptor. I have it set to Mic and Mono.

I am truly stumped. It is also very weird that I can't hear the hum through the headphones. Also makes it

Argh. I am in hum removal hell.
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Old December 28th, 2007, 04:28 AM   #6
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Quote:
Originally Posted by Eva Sollberger View Post
Thanks for your suggestions.

Steve! I got so excited thinking that you had found the answer but no, the hum is in the tape I think. I tried listening to the audio tests I have been doing with the Canon GL2 plugged directly into the fancy new Studiophile DX4 speakers I bought and the hum is still there. Also, the audio levels are oddly low.

I tried digitizing video from my recent audio tests using the Canon GL2 instead of my normal "deck," a Panasonic PV GS200. Both yielded the same result: the sound from audio recorded with my on camera Canon mike is fine and audio recorded using the Beacktek and the Rode NTG-2 is infected with this high pitched hum.

Postproduction is Final Cut Pro 5 and a G5. What baffles me is that the on camera mike records and digitizes fine!?

Bill, agreed, it is a great site. I am also new and found only one post referring to the hum associated with the Beacktek, the Canon GL2 and Rode NTG-2 Combo. Am I looking in the wrong places?

Ken, I am not using an ACDC adaptor. And The Line/Mic switch is on the Beachtek which I guess is my adaptor. I have it set to Mic and Mono.

I am truly stumped. It is also very weird that I can't hear the hum through the headphones. Also makes it

Argh. I am in hum removal hell.
ALL of the audio in that piece was recorded with the Rode/Beach combo?

Some Beachs a couple of years ago had a grounding problem that could introduce hum which was remedied in more recent production. If you got yours from a private individual you might have one of the older ones or if you bought from a dealer perhaps it was old stock. At any rate, I understand Beach was very helpful with people experiencing the problem so you might get in touch with them directly.
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Old December 28th, 2007, 04:51 AM   #7
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I, also, believe the hum is probably coming from the Beachtek.

I haven't used an adapter for a while, but I used to use another brand (Sign Video XLR Pro, formerly sold by Studio One, but now sold by SignVideo, the maker). Hum was a possibility and the one I had had a special switch for some situations to get rid of the hum (ground lift switch?). I remember the Beachtek at that time could have a hum.

You might get a single line adapter (a cable with the correct matching ransformer) and try the mic on your camera, eliminating the Beachtek to see if this eliminates the hum. Here is a link to what I am referring to:
http://www.warehousesound.co.uk/stor...hp?prodID=1194
Audio Technica makes one, other companies make them, shops put their own together, and I think radio shack sells one. ( I would get a name brand one such as Audio Technica if I bought one -- I do have one, but I don't know what brand.) If there is an audio shop, you can try this to eliminate the Beachtek and see if that gets rid of the hum just to narrow down the problem.

Certainly, calling beachtek may well solve your problem. They should be helpful and know any of the possible problems their device may be causing.

If you have the same hum in a number of tapes, are they shot in different locations? If so, this should eliminate the possibility of something in the environment causing the hum.

How long is the cable run from the microphone to the Beachtek and the Beachtek to the camera? Is the Beachtek plugged into the camera without an extension? Is the mic on the camera with just a few inch run to the Beachtek?

Calling Beachtek is probably going to solve the problem.
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Old December 28th, 2007, 07:27 AM   #8
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Sorry to add a 'me too' to this, but, well, me too!

I had an issue with the Beachtek on my Sony VX2100. It all worked fine until I screwed it into the tripod mount on the bottom of the camera. As soon as the Beachtek screw touched the camera, hum started. I had grounded the camera as per the Beachtek advice but it didn't make any difference, so was probably a faulty unit.

Interestingly (or not), I also had issues when using a simple, short XLR-3.5mm stereo jack lead with the NTG-2 on my Sony, the hum was awful there. The same mic is superb on my new V1.
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Old December 28th, 2007, 11:18 PM   #9
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Thanks for feedback! The Beachtek was bought new from B & H and my sound has been compromised ever since I stared using it. Sadly, I didn't figure out the sound was bad until I bought speakers recently so I have about 10 vlogs with crappy sound now.

I am talking to Beachtek right now about the issue. The hum is on all the tapes but the weird thing is that you can't hear it in the headphones, only when I run it to speakers.

I'll try the adaptor cord plug as a test! To answer questions:

How long is the cable run from the microphone to the Beachtek and the Beachtek to the camera?
About 6 inches

Is the Beachtek plugged into the camera without an extension?
yes.

Is the mic on the camera with just a few inch run to the Beachtek?
Yep.

THANKS! I have a shoot tomorrow and will be using the on camera mike. How aggravating.
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Old January 5th, 2008, 08:41 PM   #10
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Problem Fixed!

Hello!

THANKS YOU to all of you for your generous help and suggestions! I finally fixed my hum problem and the solution was ridiculously simple!

The painstakingly sought after hum source was that the shotgun mike was not sitting in the holder properly and the camera motor was vibrating on the shotgun and causing a hum. At least, that is my best guess. All I care about is that the HUM IS GONE! FINALLY!

Thanks to this saga, I learned to always listen to sound through speakers and headphones.

I'd like to thank Harry Kaufmann of Beachtek who tirelessly helped me troubleshoot this problem. In the end, the Beachtek is working FINE and Harry was very helpful toward figuring this out!

Live and learn!

All the best,
Eva
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Old January 5th, 2008, 10:51 PM   #11
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Told you so. :)

But you said you weren't hearing it in your headphones. What's up with that?

Regards,

Ty Ford
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