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Probably REALLY simple...

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Adam Keyes
Probably REALLY simple...
on Jul 1, 2010 at 8:08:32 pm

Tons of noise and I don't know why!!!!

Using a brand new Lectrosonic 400 series wireless ($2,000 i think). Mic is properly placed, receiver is 20 ft away, XLR into Varicam 2700 ($40,000 camera). Batteries are fine. Using only 2 Lowell lights (Tota and Rifa). Shooting in a large room, mostly silent.

I've messed w/ the audio level on the receiver and on the camera, but there is always tons of noise. Not interference, just freaking hiss/hum/etc. Surely it's not the lights right???

I can try to link to the raw audio if you want to hear it, but it's ridiculous. I EQ it out as much as I can, but I can still easily hear it.

Oh, my output is LOW, around -20 or -30 db reading on the camera.

Any help would be GREATLY appreciated. Surely it's a simple fix???

Cheers,

Adam


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Adam Keyes
Re: Probably REALLY simple...
on Jul 1, 2010 at 8:21:14 pm

here's a sample of what i'm talking about, let me know if you can't download...

files.me.com/prohd/qvncoh.mov


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Terry Mikkelsen
Re: Probably REALLY simple...
on Jul 1, 2010 at 8:37:21 pm

It is possible that there is an automatic setting on somewhere (compressor, leveler, etc....)?

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http://www.technical-t.com


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Adam Keyes
Re: Probably REALLY simple...
on Jul 2, 2010 at 5:38:07 am

not sure, would that setting be on the pack? receiver? camera?


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Thax Clave
Re: Probably REALLY simple...
on Jul 1, 2010 at 9:09:04 pm

Are you feeding a LINE-level output into a MIC-level input?



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Adam Keyes
Re: Probably REALLY simple...
on Jul 2, 2010 at 5:40:58 am

thanks for the reply...

not sure. if you listened to my sample, you know that i'm in the local tv car commercial business, which means: no time to think, JUST SHOOT! :)

all our gear is basically right out of the box, turn it on, and go.

i'll have to check on the mic level / line level, etc....

thanks again,

adam


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Ty Ford
Re: Probably REALLY simple...
on Jul 1, 2010 at 9:31:32 pm

Hello Adam and welcome to the Cow Audio Forum.

Although remote operational discussions are hampered by the distance. It sounds as though you may be exiting the receiver at mic level with the camera set to receive line level.

Try getting that sorted out and see what happens.

Regards,

Ty Ford

Want better production audio?: Ty Ford's Audio Bootcamp Field Guide






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Richard Crowley
Re: Probably REALLY simple...
on Jul 2, 2010 at 1:04:21 am

Exactly which model transmitter and receiver are you using? Lacking that information, generic advice is:
Is the audio level set properly at the transmitter?
Is the audio level set properly at the receiver?
What does the audio sound like directly monitoring out of the receiver?
Is the receiver set for mic-level or line-level output?
Is the camera expecting mic-level or line-level input?
What does the audio sound like when monitored on the camera during shooting?

The audio level indicators on the camera should be a good clue that you have a dramatic level problem somewhere. But not enough information here to determine where the problem might be.

Has this ever worked in the past?
Are you using new equipment that hasn't been set up properly?


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Steve Kownacki
Re: Probably REALLY simple...
on Jul 2, 2010 at 2:43:06 am

I hear some hiss but alot of hum.

Is all the gear on batts?
Have you swapped out the XLR to the cam?
Only your lights; no fluorescents or cheap wall dimmers around?
Have you moved the location of the cam and receiver to different spots in the room? There could be high voltage conduits in the floor or ceiling inducing that.



Steve



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Steven Talley
Re: Probably REALLY simple...
on Jul 2, 2010 at 2:34:01 am

My 2cents
It sounds like hum, likely a grounding problem, What components are plugged in to wall outlets? Maybe move one to a different circuit or run off batteries. Or use noise removal filter in software (but it won't sound natural).
Good Luck


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Will Salley
Re: Probably REALLY simple...
on Jul 2, 2010 at 3:31:56 am

Go to the receiver and engage the 1k tone. If your inputs are set to MIC level and the receiver is not attenuated (it should be at 0db), you should hear clean tone and see good meters on the camera.

Also, if you are using the UM400a transmitter, it adds 10db more gain than the older model, which sometimes sounds like more RF hiss.

Let us know what you find.



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Adam Keyes
Re: Probably REALLY simple...
on Jul 2, 2010 at 5:55:16 am

THANK YOU EVERYONE, i started replying to each of you, but i'll just do this instead. :)

seriously, thanks for responding. audio problems make me laugh, cause i have no idea what is going on!!!

other background info: we're shooting in a car dealership showroom, using a heavy duty jib for the camera, lowell light kit (often several things running off same wall outlet), only thing on batteries is the mic transmitter and receiver, everything else off wall outlets. but even so, could that really be causing the signal to go THAT bad? maybe so...

general answers to some of your questions:

1. not sure if it's line/mic level at mic/camera, i'll check
2. not sure which specific series lectrosonic mic i'm using, i'll check that too
3. mic and camera are basically STRAIGHT out of the box, turned on, and go. no adjusting settings, etc. this, i'm sure, has something to do w/ it. ?
4. i think levels are set properly on mic/camera, but i don't know what "proper" levels are for each piece of equipment. i guess more playing around will help there

THANK YOU everyone, i have a LOT to go back and check out. i'll check what you guys suggested and hopefully you won't hear back from me!!

thanks thanks thanks,

adam


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Ty Ford
Re: Probably REALLY simple...
on Jul 2, 2010 at 12:10:04 pm

Hello Adam,

You are on the right track. Good audio is not plug and play. It's not brain surgery, but it does take experience and knowledge. The good news is that you opted for good gear and once you sort it out, you'll have solid audio. Don't be afraid to call Lectrosonics for help but absolutely read the manual and do your own reserch.

Regards,

Ty Ford

Want better production audio?: Ty Ford's Audio Bootcamp Field Guide






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Bill Davis
Re: Probably REALLY simple...
on Jul 7, 2010 at 4:56:09 am


I'm scared by the words "car dealership showroom." As the past owner of an ad agency that had the local Cadillac dealer as a long time client - there's NOTHING I hate more than car dealership showrooms.

They're typically lit in such a way as to make all the nice shiny cars sparkle - yet it's the nature of most dealerships to be as CHEAP as possible on construction and stuff like light fixtures and wiring.

In addition, the one's I've worked most in love stuff like dimmers on their lighting circuits so they can make the place look ever so ELEGANT by cutting the lights down

My initial suspicion is that you're shooting in a veritable HIVE of RF.

If so it's time to either hire an audio guy or spend some time learning how to do audio properly yourself.

As you're learning, Audio is the most difficult part of video. And it can't be faked.

Spend the money to do it right, or understand that if you expect your audio gear to simply "plug and play flawlessly" without any real understanding — your operation is going to fall seriously short of professional at this point in your business life.

Simple as that.

Your call.



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Ty Ford
Re: Probably REALLY simple...
on Jul 7, 2010 at 5:01:43 am

Bill's right, Adam and obviously has the scars to prove it. :) Even ones that don't show on the skin!

Welcome to the brotherhood/sisterhood of sound and audio. Watch where you step. There's a cable waiting to entangle your foot. :)

Regards,

Ty Ford


Want better production audio?: Ty Ford's Audio Bootcamp Field Guide






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Adam Keyes
Re: Probably REALLY simple...
on Jul 7, 2010 at 12:10:22 pm

Haha, thanks guys,

Sounds like I'm in a similar situation as you used to be Bill, regarding the location...

The showroom is actually really nice (at least on the surface :), but there are indeed a million light fixtures and I'm sure they're all on dimmers.

Something else I forgot to ask about....obviously the camera itself has a input record level that i can adjust, and the mic has an output level...should these two levels be about equal (as in, both around 25% of maximum), or should one typically be much lower than the other....or is it just a trial and error kind of thing? :)

Oh, and what does this mean: "HIVE of RF" ? radio frequency?

Thanks so much guys,

Adam


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cowcowcowcowcow
Bill Davis
Re: Probably REALLY simple...
on Jul 10, 2010 at 5:44:59 am


Adam,

That's exactly what RF means. Radio frequency energy. In a situation with a lot of RF present - ANY metal cable will act as a giant antenna. Properly balanced cables that are also used properly in a balanced audio system use a phase cancellation trick to knock down this type of audible interference - but if there's enough of it around, it can be VERY pesky to totally avoid.

Two notorious sources of RF are older style dimmers and older style fluorescent light ballasts. Both of which tend to be very common in brightly lit auto showrooms.

Thankfully, it's really easy to find out if this is the issue. Go in after hours. Set up your gear. Then pop the breakers and/or switches on all the various lights and if your audio problems disappear, that's the issue. Then you can try bringing them back on-line one at a time and you might discover that the ceiling cans are OK, but another circuit is not.

At the worst, you'll have to leave the "house lights" off - and illuminate the showroom and cars with your own gear that DOESN"T generate RF.

That's where I'd start, anyway.

Good luck.





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