Study Hall

ProSoundWeb
Photo courtesy of Allen & Heath.

The Broadcast Mix, Part 2: Detailing Both Aux & Group/Matrix Approaches

The aux mix is basically a monitor mix for the broadcast feed, while the group/matrix mix is a different thing altogether. Let’s dig into using one or the other.

Previously (here), we considered two ways to deliver a better online audio mix for our at-home congregation. To recap, we don’t want to use the main mix because the levels and mix will be sub-optimal, so instead let’s use either an aux mix or a group/matrix mix.

The aux mix is basically a monitor mix for the broadcast feed, while the group/matrix mix is a different thing altogether. Let’s dig into using one or the other.

No Groupies

The first and most obvious reason to use an aux mix is that your mixing console either lacks groups or they’re already in use for other things. In this case, it’s “no groups for you!”

However, there are other reasons to go with the aux route even if you could use groups. The main reason is if the room is small and some of the instruments aren’t really “in the mix.”

The group/matrix method is predicated on a well-balanced live mix. If the drums are loud enough in the room that you don’t put them in the house mix, they won’t be in the broadcast mix. If there’s a guitar and bass amp on stage that are “loud enough,” they will be missing, too. And that’s just sad.

Using an aux mix allows putting the entire band on the broadcast mix even if they aren’t in the house mix. Note that the broadcast mix must be monitored a little more closely to be sure the levels are right and nothing is taking over.

If your console offers pre-fade and post-fade options on its aux sends, which one should you choose? Well, it depends. If the console offers the option of selecting pre- or post-fade for each channel on a given aux mix, then the choices can be customized. On the other hand, if the console offers either pre-fade auxes or post-fade auxes, go with pre-fade.

The reason is simple – if you’re using a pre-fade aux and don’t put the drums in the house mix, they also won’t be in the broadcast mix. The key point to remember here is that if the microphone is on, it’s going to the online mix. So, pastors are going to have to turn their wireless mic packs on and off during the service. I don’t like this, but you’re stuck with it on very simple mixers.

Assuming you can select pre- or post-fade on a per-channel basis, here’s what I recommend: Put all the instruments that aren’t in the house mix in pre-fade mode and put everything else post-fade. This way, when vocalists stop singing, you mute or turn down their mics (you do mute or turn them down, right?), and thus they’re off in the broadcast mix. Pastor wireless packs can stay on the whole time, and you can bring them up or down in both mixes together.

Note that it does take a little more monitoring to ensure that all the send levels correct, but it will yield the best results. The drum mics will be on during the message, but it shouldn’t be a huge problem assuming the mics are set up well.

I don’t like this approach as much as the group/matrix method because it takes a little more work each weekend to ensure things are dialed correctly. However, if you’re not putting the entire band in the main mix at levels that mix well together, it’s likely the best option.

On The Other Hand

If your overall main mix is good, routing channels to a group, then using the matrix to level balance them, is a better way to go. Once the overall levels are dialed in, it doesn’t take any extra work to produce a quality online mix.

You can focus on building a great house mix and that tracks through to the broadcast – at the correct levels – without any additional effort on your part. Put some mild compression on each group if things do start to drift a little bit, but it will mostly auto correct. Bring the mix up in the headphones once or twice during the music and message, monitor the output levels and it’s good to go.

But – and this is a big but – it only works if the main mix is good. You also must remember to patch channels into the appropriate groups if you rearrange the console each week. Accidentally leave a guitar channel patched into the speaking mics group and the online congregation will be firing off nasty comments before the first chorus. The solution, of course, is a standardized console layout that accommodates the largest setup you’ll ever use. But that’s a different article.

Cherry On Top

There are a few additional items you can add to a broadcast mix that can make it that much more engaging. Input from audience mics tops the list. If you’re using in-ear monitors with the band, you probably already have some (and if not, you should). This input can be added to the mix to help provide an “in the room” sound that’s critical for engaging an at-home congregation.

The tricky bit about audience mics is getting the level and the timing set correctly. With an analog console, the level will have to be a compromise and the timing will be what it is.

Digital boards provide more flexibility. Experimenting with a little bit of delay on the audience mics will likely lead to improving the sense of ambiance without hurting intelligibility. There are many methods of doing this – balloon pops, looking at waveforms on digital audio workstations (DAW), complicated math – but I’ve found it best to do it by ear. Essentially, add delay a little at a time until it sounds right.

As for levels, we don’t want to be pumping a bunch of the PA into the broadcast mix, but if the band goes into a breakdown and it’s a moment of congregational singing, we do want that dialed up. When pastors are speaking, we don’t want to hear their voice bouncing off the walls and coming back to the mics, but we do want to hear the congregation laugh at their jokes.

A basic compressor will accomplish this reasonably well. It will take a while to get it dialed in right, and you may have to spend a few weeks making adjustments, listening to the mix and adjusting again. Stay with it, you’ll get there.

If your room is properly acoustically treated and the mics are well-placed so as to not pick up too much pastor voice, you can side-chain the compressor to the band group. That will effectively turn the audience mics down when the band is playing and turn them back up when they stop or get quieter. This works really well once set up properly.

Room mics can create a similar effect. They’re different from audience mics in that they are picking up the entire room, not just the audience. Again, level and timing are critical to making these sound right and not hurting intelligibility. I advise only adding them once the rest of the mix is rock-solid.

Study Hall Top Stories