Mix Positions to Avoid
One of the most important things you can know about setting up mixing consoles is the positions to avoid. And if you do have to set up in these positions, you should understand exactly what you’re getting yourself into.
First, the worst place in the world to set up a front of house console is in another room—that is, in a sound booth. Venues sometimes use these in the interest of security; if everything’s together in one room, it’s easy to lock it all away. (And, again, you’re not taking up any valuable audience space.) As much as this might be an advantage for the venue and promoter, you’d do just as well mixing the show from the pub around the corner. No matter how big the hatch or window to the room is, the sound is always massively different from what the audience hears.
Another place that should be avoided is under balconies—or, more accurately, anywhere near balconies. If you’re immediately below the balcony, you run the risk of people spilling drinks or food on your equipment (as we mentioned). However, if you’re under the balcony, you get reflected frequencies from the ceiling, which can cloud your audio image and give a false impression of the balance in the room. Another risk of being under the balcony is that you may not be able to see the PA, which means you aren’t getting any direct sound from the PA, and thus you’re trying to mix something you can’t hear. Again, you might as well go to the pub around the corner.
When it comes to audio, walls are usually pretty reflective. Being pushed into a corner or up against the back wall of a gig will give you a colored image of the sound. Low-end frequencies are a lot more noticeable within these areas. When you come within about 9 feet of a wall, you are beginning to enter what is known as a pressure zone, or boundary effect. The overall volume or possibly certain frequencies are increased in this area, which happens because of standing waves. When soundwaves strike a hard surface, the waves are reflected and combine with the incoming waves, so the sound pressure is increased near the surface. These reflections also cause comb filtering and boomy bass, which lead to very undefined audio and can make it generally impossible to accurately mix a show.
The other no-go area is on the side of the stage. This location is perfect for a monitor engineer, but front of house engineers won’t be able to hear what they need to hear because they’ll be behind the speakers so all the audio is heading away from them.
Acceptable Mix Positions
One example of an acceptable mix position is on top of a riser. If you’re going to be on any sort of raised platform, though, you need to understand a few principles. Sometimes above the audience there is what is known as a humidity layer, which is a layer of heat and moisture generated by the audience sits a few feet above the heads of the audience, very much like the floor of a rain forest. This layer acts like a shield and causes some of the harsh frequencies to bounce off the top of this layer straight into your hearing field. As a result, you hear a lot more high-end frequencies than you would hear if you were in the audience. The effect varies depending on the size of the venue and on whether you are indoors or outdoors; heat and humidity are much more likely to be trapped in a small indoor venue than a large outdoor festival. If you do end up on a riser, make sure to get off it and listen from the floor every once in a while.
The side of the room is another acceptable place for the mixing console. You won’t be affected as much by standing waves; you will, however, still be getting reflections off the walls, and you should be careful you aren’t too near the pressure zone. The obvious flaw with being off to one side is, of course, if you use a lot of stereo imaging (such as panning guitars left and right) or effects that are in stereo; if this is the case, you won’t be able to hear the stereo imaging that is happening elsewhere in the room. Center-panned images will appear to you to be all the way toward the side on which you are standing.
Ideal Mix Positions
The ideal mix position is the center of the room. This is the sweet spot where all points of audio come together and are audibly in focus. If your system is set up correctly, you shouldn’t have any summing down the center line, which is caused when two identical soundwaves meet and then sum together, causing certain frequencies to be louder. As you are mixing the show, it’s always a good idea to move left and right on and off the center axis; sometimes you can’t get the system to sound completely perfect in the center, and being slightly off center can help. Remember, though, that summing can still occur for the same reasons, and when you are off center you can get some forms of cancellation. Remember that you are mixing for the audience; moving on- and off-axis will give you a better indication of what the audience is hearing.
As should be clear by now, mix position is just as important as speaker placement. Despite this, it isn’t always possible to get an ideal mix position in a venue—you will have to compromise from time to time.
About the Author
Mixing Engineer, Live and Studio Audio Engineer, Tour Manager, Tour Consultant Toured Extensively in Europe, North America, South America, Japan Mixed & Supervised countless sessions including: Itunes, Aol, Yahoo, BBC, B-side cuts… Live TV appearances include: Jay Leno, Saturday Night Live, Dave Letterman, Austin City Limits, Conan O’Brien, Regis & Kelly, VH1, Later with Jools Holland, Brit Awards, Live at Abbey Road, BBC One Sessions, Parkinson, Friday Night Project, Album Chart Show, E4, Taratata, New Pop, Jonathan Ross, Alan Carr, Top of The Pops, CD:UK, T4, Davina, Mobo Award