improving one camera audio of a theatre event

[Don Greening]

If you’re going to use your theatre audio system for your camera audio you’ll need to pad the signal down to something the camera can deal with. Most mixers peak at +10 dBu and DV cameras peak at -12 Dbu. Even if you’re not an audio guru you can plainly see the huge discrepancy between the two. The other principle rule is that you can’t afford to clip a digital signal because once you do the audio instantly turns into hash, unlike the analogue days where you had more latitude: you could have a hotter signal and it would still be somewhat usable because of the nature of how analogue is recorded. The audio tracks on a Mini DV tape are about the size of a pencil line, so there’s not much room for error and even less available headroom. You also need to practice proper gain staging, starting with the house mixer and adjusting the volumne of the camera lastly to get the proper signal to noise ratio.

With your GL1 it’s imperative to record using the mic ATT setting which you’ll find in the camera’s menu. You’ll also need a couple of adjustable inline attenuators to reduce the signal from the house system even further. Since your GL1 has only a stereo miniplug for external audio you need to go from XLR cable to the miniplug.

Have a look here for the pro way of bridging that gap:

https://www.beachtek.com/

Here’s another link to the type of inline attenuators you’ll need to do this right:

https://www.audio-technica.com/cms/electronics/a05620466ab0ce16/index.html

Mr. Vanderbilt, you could also hook up your own mixer between the camera and the house system but the above method will be the quickest setup and the way I would approach the situation you’re faced with. The above way I’ve described is probably not the cheapest, though. But like they say in the car racing world: “speed costs money, how fast do you want to go?” Also, monitoring your incoming signal with a good set of headphones is absolutely critical to achieving good sound, but you probably already knew that.

– Don

[Todd Gillespie]

Hi,
Don had some great advice.

Since we do a lot of event video at theaters, halls, etc, we run across the same set up.
taking the feed from the ‘house’ is usually the easiest and best option. Since they should have already invested the time and energy to making everything sound good. We will run that feed thru our Mixer (Mackie) then into the camera/deck. (Also suggested by Don) The reason being is that we need to control the volume differently than the live audio would. If you run straight into the camera, then your hostage to the level on the board which is concerned with the sound quality for the live audience, much different for video. For our ‘field cart’ (GL2 with VCR & Monitor) we run the feed thru a Radio Shack 4 line mixer. It’s cheap, it’s ugly, but it works. You can switch between Mic-Line level and has a Master level. I would recommend getting a Shure field mixer. They are very nice and compact with a lot of features.
https://www.bhphotovideo.com/bnh/controller/home?O=productlist&A=details&Q=&sku=118708&is=REG
Also you should run Tone thru your sound path before you start taping. This is critical in setting a sound level. I imagine that if you did it now, your tone would come thru to hot.
https://www.bhphotovideo.com/bnh/controller/home?O=productlist&A=details&Q=&sku=197233&is=REG
Bringing your own mics will add a lot of work, and shouldn’t sound any better than the mics already in place.

Good Luck,

Todd at UCSB
Television Production