Today we have a guest post. Well, mostly guest, I'm going to comment on it first (and probably last--it's still my blog, after all...). Upper Room's Lead Sound Engineer and good friend Erik Jerde was mixing in another room on Sunday and came up with the the trick we're about to share.
The challenge with stereo is a live situation is that about 3 people actually get a stereo mix, and the rest of the room get something that just doesn't sound right. On the other hand, if you can get stereo to work, it opens up your sound field and gives you more "room" to mix. I'll let Erik take it from here.
When mixing on a stereo system the engineer wants to pan sources and create an interesting and acoustically wide mix. Done well this produces a great mix for people who are in a position to hear the stereo mix. Unfortunately that's not the majority of the audience. The majority of the audience hears a mix different from the FOH engineer because they are hearing primarily the left or right channel only. This means that anything you want all the audience to hear needs to be kept panned at center, or very near center. This ends up stacking up everything in the center sonic space and significantly limits the width of the mix.
This morning I was in a situation where I had one BGV which I wanted to pan left. However due to the reasons mentioned above I couldn't do that without making it very difficult for half of the audience to hear. Fortunately for me I was mixing on a digital console with input delay available on each channel and I had spare channels. I took my BGV input and using digital patching sent that input to two channels. I then panned the channels left and right to get the width I wanted for the BGV in the mix. I didn't go hard left and right, but I did go a little past 3 and 9 o'clock on the pan. Now comes the secret sauce. At this point there still wasn't any kind of stereo feel to the mix. The key to getting the stereo feel is the digital delay. I went to my right channel and delayed the input 0.7ms. Standing in the center of the room the BGV now was noticeably coming from the left side. This is due to the fact that the left channel audio arrived 0.7ms before the right channel audio which tricks the brain into placing the source to the left. I played around with various levels of delay, from 0.3ms to 1.2ms and found that in my space 0.7ms gave the pan feel I was looking for while not being noticeably delayed. I then kept the two channel faders at the same level while mixing.
The end result of all this is that the bgv now had width in the mix, a stereo feel, but remained fully audible and appropriately placed in the mix in all seats in the house. This has the added bonus of creating more acoustic space in the center of the mix for the lead vocal which allowed me to keep that lower but still maintain clear definition on it and the feel that it's in a pocket on top of the mix.
Unfortunately this isn't an option on boards like the M7CL or the LS9 which don't have input delay. But if you find yourself on a system where you've got the technology, extra channels, and the time to make it work, give it a shot, it definitely makes your mix more fun.
Normally, I'm not a big fan of stereo PA in a room, because for the most part, you end up doing everything mono anyway. But if you can pull this off, it adds an extra dimension to the mix. Thanks, Erik, for sharing this tip!