How to produce a live concert video on a budget – Capturing Audio

The key to a good audio mix is getting all of the instruments to sit in their own space or in the right space using any and all of the tools at your disposal. Most live recordings are captured “bootleg” style with a recording device in the room or with a stereo mix taken from the mixing board. While many of these sound surprisingly wonderful, they offer little flexibility for editing. Luckily, most modern mixing boards include “direct out” or “insert” options which allow you to tie into each individual channel on the mixing console and route it to another place. In our case, it’s a pair of audio interfaces. These options are also generally pre-fader which means that the fader, EQ, sends etc… are not included. However, the channel gain is included and this is very important to remember as we will see.

The venue had a 24 channel Mackie mixing console and I took inserts for 16 channels into two SONAR VS-700R interfaces and captured on my lap top with SONAR Producer. Again, the hardware and software you use doesn’t really matter as long as it can perform the functions described. The image below shows the routing scheme. Two things to note here; First, when using channel inserts, a TS or TRS cable is required and the cable should be inserted to the first click, not all the way in. Second, when using two interfaces together like this, it’s best to sync them together via wordclock. This was done very simply by connecting a BNC cable from the output of the first interface to the input of the second. Make sure that your interfaces are set up correctly as master and slaves. The VS700R required a jumper switch adjustment to do this. Syncing your interfaces will prevent any drift in the audio between them. Correcting drift can be a long and painful process, so you’ll want to avoid this at all costs.

This shows how we captured the audio. From the mixer to the interfaces and finally to the lap top.

Using a SONAR template created in advance, I had a project setup up to receive each of the 16 inputs on 16 tracks. The last and very important step was to make sure that the levels were in a safe range. This is where the channel gain controls on the mixing console come into play. Our friend and fellow musician Jack came in that evening to mix the band and assist with the audio. We adjusted the channel gains to optimize levels for the recording so when mixing the room for the live event Jack could make all of his volume adjustments on the faders without affecting the recording.

An external USB hard drive was used as the audio folder. We recorded 16 tracks at 16/48 without a glitch. With over 2 hours of music this used up almost 20GB of space. Here’s how we set it up:

4 vocal mic tracks

4 drum mic tracks

1 mono keyboard track

1 bass track

1 sax track

3 guitar tracks ( 2 acoustic and one electric)

2 room mics (mixed in to give the recording more of a live feel if needed)

These tracks were captured and ready to mix for video.

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About Dan Abreu

Music, Audio, Video, Technology and other fun stuff
This entry was posted in audio, video. Bookmark the permalink.

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