View Full Version : XLR Gainup not working


Joachim Hoge
September 18th, 2007, 09:22 AM
I had my first day of shooting on a documentary today. The first day with the camera as well and everything was working fine except the AUDIO SETUP meny.
My sound man wanted to gainup 12db and I went into the Audio menu, but the option R-XLR GAINUP was in grey letters and could not be accessed. I tried to call Canon, but they had to come back to me as they rep didnīt know much.
Anyone here have a clue?

I was in manual mode.

Joachim

Per Johan Naesje
September 18th, 2007, 12:56 PM
Joachim,
check the following:

-set the +48V phantom switch to ON if the mic support phantom power
-set the MIC/ATT switch to ATT
-IMPORTANT! check that the LINE/MIC switch is set to MIC !!
Then try to change the setting in the menu to 12db

I don't have the camcorder present, so I can not check this but try what I'm suggesting.

Daniel Browning
September 18th, 2007, 01:02 PM
I had my first day of shooting on a documentary today. The first day with the camera as well and everything was working fine except the AUDIO SETUP meny.
My sound man wanted to gainup 12db and I went into the Audio menu, but the option R-XLR GAINUP was in grey letters and could not be accessed. I tried to call Canon, but they had to come back to me as they rep didnīt know much.
Anyone here have a clue?


The XLR gain up only works on mic-in sources. The problem you're experiencing has been discussed before:

http://dvinfo.net/conf/showthread.php?t=91427

Essentially, the A1 is spec'd for +8dBu line in, when 0 or 4 is normal for professional gear.

Joachim Hoge
September 18th, 2007, 02:12 PM
Joachim,
check the following:

-set the +48V phantom switch to ON if the mic support phantom power
-set the MIC/ATT switch to ATT
-IMPORTANT! check that the LINE/MIC switch is set to MIC !!
Then try to change the setting in the menu to 12db

I don't have the camcorder present, so I can not check this but try what I'm suggesting.

Takk Johan.
It solved the problem and created a new one.
The mixer (Soundevices) we used only had line, not mic. This is quite common.
This is a big drawback with the camera as far as I can see. We will get a mixer with mic and line next time, but not all soundmen have that.
I donīt understand why it canīt be done in line mode.
One do all the research, all the reading, but some aspects/drawbacks you really never find out about until you are out in the field

Dan Keaton
September 19th, 2007, 05:09 AM
Which Sound Devices mixer are you using?

You may be able to adjust the output level of the mixer.

Dan Keaton
September 19th, 2007, 06:01 AM
The Mix Pre has line level outputs, but can be easily attenuated to mic level using special cables or attenuators.

The Sound Devices 302 mixer has active-balanced line/tape/mic level outputs on XLR connectors.

The Sound Devices 442 has transformer-balanced line/tape/mic level output on XLR connectors .

Joachim Hoge
September 19th, 2007, 01:55 PM
Hi Dan.
Thanks for your replies.
Iīm not sure what model we used. I do know that they will bring a model with both line and mic next time. We managed to get good sound, just a little low levels. I think he turned off the limiter to get some extra level.
It wonīt be a problem next time, but itīs something I have to tell sound men about before we shoot. Itīs not a problem if we are renting gear, but quite a few of them have their own gear.

From your post it seemīs like a good idea for me to buy a set of cables that can attenuate the line level that I can have in my kit.
Do you know what kind of cables that would be?

Dan Keaton
September 19th, 2007, 04:53 PM
I would buy two xlr attenuators, made by Shure.

http://www.bhphotovideo.com/c/product/68600-REG/Shure_A15AS_A15AS_In_Line_Attenuator.html

Joachim Hoge
September 20th, 2007, 01:53 AM
Thanks for the link Dan, much appreciated. (Finally an accessory thatīs not expensive ;-))

Dan Keaton
September 20th, 2007, 05:04 AM
Dear Joachim,

You're welcome.

I am about to order two of these myself.

Dan

Joachim Hoge
September 24th, 2007, 02:34 AM
Hi Dan
I talked to a sales rep here in Norway and he told me that these Shure attunators would not do what I need them to do. He said that to obtain gain I needed a mixer or amplifier of some sort.
Is this right you think?

Dan Keaton
September 24th, 2007, 07:10 AM
Dear Joachim,

Sorry, but I feel that he is wrong, in this specific case.

Yes, it is impossible to use attenuators to obtain gain.

But, in your case, you need to reduce line level to mic level in order to use the "Gain Up" feature of your camera. As such, attenuators are what you need.

Then, once your inputs are attenuated from line level to mic level, and you have the camera set to "Mic", then you can use the "Gain Up" feature.

Joachim Hoge
September 24th, 2007, 11:20 AM
Dear Joachim,

Sorry, but I feel that he is wrong, in this specific case.

Yes, it is impossible to use attenuators to obtain gain.

But, in your case, you need to reduce line level to mic level in order to use the "Gain Up" feature of your camera. As such, attenuators are what you need.

Then, once your inputs are at line level, and you have the camera set to "Mic", then you can use the "Gain Up" feature.

Thanks again Dan. I see how this works out now. Iīll call back tomorrow to place an order.

Johan Forssblad
September 26th, 2007, 02:48 PM
Then, once your inputs are attenuated from line level to mic level, and you have the camera set to "Mic", then you can use the "Gain Up" feature.

Hi,
You better get or make attenuators with correct levels so you don't need to use the "Gain Up" if you don't want even more noise. The attenuators are there to decrease the level from the mixer's line level (which unfortunately is too weak for the line input at the Canon) to a weak level which your mic input can handle at the camcorder. Don't attenuate it so much so you have to amplify it even more. Good luck!

Dan Keaton
September 27th, 2007, 07:03 AM
The attenuators that I recommended have three levels of attenuation.

So, if desired, one channel could be attenuated more than the other, simulating a "Gain Up".