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AGC or Compression?

mroy's picture
Last seen: 4 years 8 months ago
Joined: 12/20/2009 - 12:24am

In my school's auditorium we shoot most shows with our built-in 3 camera video system. For audio, we have four 1/4" cables feeding outputs from our house sound mixer. Our problem is that the house mix is always focused on what the name implies, the sound for the house. This causes issues with the balance of the inputs when we feed our video system. In an ideal situation, we would take a direct output from each channel on the house mixer and run a seperate video mix upstairs, but with our budget and staffing limitations, this alternative isn't possible.

As much as I would like to convince myself, the students running this system won't always have audio on their minds, (one person runs 3 robotic cameras as well as the switcher and audio levels) meaning at times the audio will be too low, and other times it will distort. Also the performers on stage don't always have the best mic handling/vocal technique, causing sudden dips and peaks. From my experience these dips and peaks are almost impossible to correct fast enough by just riding the fader on the mixer

I have been looking at the different options out there, and to me at least, compressors look like the best solution. All I'm really looking for is an "auto gain control," but all I have seen in rackmount units are compressors that only lower the loud parts, instead of doing that AND raising the quiet parts. Is this what a "compander" would do?

My biggest concern is maintaining the integrity of the sound. I don't want to over-compress the choir, but that doesn't even matter if we can't hear them, or if the sound is distorted.

With our mics and wiring being so out dated, we tend to end up with a "muddy" or "weak" sound. The school band sounds bland, the drums have no punch, and the dynamics are just all over the place. There is no changing our house sound system with our current budget, so I'm looking at other ways to improve clarity, without breaking the bank.

My thought was to take two of the outputs from the house mixer, and run a stereo feed to our small mackie mixer upstairs. From here I will run the feed to a stereo compressor-enhancer-noise reduction combo unit (if one exists). I need something that will level the mix, reduce room noise, and enhance the clarity of the overall sound.

I should mention that I need this for as cheap as possible, and still produce a pretty natural sound... A lot to ask for a unit that would do so much.

Thanks in advance for any suggestions, I really do appreciate all the time and knowledge people put in their comments.

-Mike Roy