The Best Mix in the HouseBy Wade McGregorcopyright 1995 - First published in EQ Magazine
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As a live soundmixer on the road, generally the first question you ask when you walk onto the stage of an unfamiliar venue is: "Where's the mix position?" The staff may point to a little fenced-off area in the back of the balcony or a half-open window in the back wall just barely visible from the stage. When you regain your power of speech, you realize that you will need some very strong reasons to support your desire to mix the evening's show from a vantage point within earshot of the PA. This can be a serious test of your powers of persuasion; after all, you will be asking the promoter to give up some very expensive seats and perhaps withstand the wrath of a few of the same people that ultimately pay your wages. WHO CARES, I'M A PROWhat does it matter where you mix from, you're a professional, right? If you can see the loudspeakers from there, you must be able to mix from there, right? Is one location in the house vastly superior to another? Are there specific locations to be avoided at all costs? What constitutes a good mix position for live concerts? You had better have solid answers to all those questions if you are going to talk your way into the good seats. Otherwise you risk having to mix the show acoustically blinded. Not a pretty sight (or sound) and often not worth the price of admission. Mixing a live show means joining the audience in a unique experience. Making this experience meet their expectations and yours may mean making hundreds of adjustments to levels, equalization and effects during a show. These adjustments will be based on how the band plays, how they react to the audience, how the audience reacts to the band and how all of this sounds in the room. You need to transfer the sound the band creates to the audience and know how well you are doing this job every note of the way. Therefore, choosing a mix position in the venue will have an impact on every mixing decision you make during the show. Here are some hints on how to know a good mix position when you see one and what to expect when you can't mix from a good location. PLACES TO AVOID AT ALL COSTS
ACCEPTABLE MIX POSITIONS...WITH CAUTIONS
LOCATIONS YOU WILL FIGHT FOR
There are many other subtle effects to consider when you have lots of time on your hands. Effects such as: listening fatigue; lack of sleep; fans who know more about how to mix the show than you do; "grazing" (where the sound bounces across the heads of the audience and changes its tone); reflections from the console and effects racks (a major problem in some recording studios, this is often swamped by more severe problems encountered in live sound situations -the room, the system, audience members leaning over your shoulder); and so on. You can't talk your way into a good mix position in every venue, so then you must walk through the room during sound check and listen to the difference between the sound you hear at the mix position and the sound in the majority of seats. As you mix the show you must try to compensate with this difference in mind. If you can find yourself a reasonable place to twist the knobs during the show and get it all back into the truck in a condition that will get you through the rest of the tour, then everything is OK. Now, whenever you are offered a choice of mixing locations you'll be fully armed with reasons why you can't mix backstage or in a sound booth. Happy mixing. email: EQMagazine@aol.com
Check out the case study of a real theatre sound system that exhibits all these problems. |
The Sound Booth: Because you don't kill any seats or sight-lines-especially in older venues and theaters-this often is the promoter's favorite location. In practice, though, it might be better to mix from the tour bus. The sound you hear in a sound booth, no matter how large the window, is completely different from sound in the house. Many sound booths are out of sight of the entire system. But even if you can look right down the throat of your horns, the low frequencies do not pass through the window unscathed. You are in a different room with different acoustical properties. (Hint: If the sound booth is so great, why don't they trade those seats with the people sitting where you want to mix the show?)
Against the Back Wall or In a Corner: The walls of a venue will usually be very reflective, so sound will be bouncing off these walls and interfering with the direct sound from the system. This causes comb-filtering and other frequency-response aberrations. As you move away from the walls the level of the reflections will diminish relative to the direct sound from the stage. This reduces the effect of the interference and also adds to the randomness of the interference to make it less noticeable. Low frequencies are most noticeably affected even where the wall is treated with sound-absorbing material. The most audible effect close to a wall is the change in bass level relative to the mid and high frequencies. This is because you are in the Pressure Zone of frequencies below 100 Hz when you are within 10 feet of the wall (the same pressure zone that gives PZM mics 6 dB more output). The bass may also be boomy and indistinct, definitely not qualities to mix by.
Under Balconies: This situation is similar to being in a corner, but with two significant additions: 1) The ceiling is also reflecting interfering sound; and 2) If the balcony is very deep, you may actually be in a different room (acoustically). Now, not only can't you differentiate the sound from the system from the sound bouncing off the walls and underbalcony ceiling, but you also can't get a sense of the overall contribution of the main part of the room to the qualities of the music. Some balconies overhang to the point of blocking the direct sound from the main loudspeakers, especially the central loudspeaker cluster in theaters. Question: Do you wanna mix this show or just baby-sit the buttons for a couple of hours?
Close to or On the Stage: This is a location that offers a few advantages of the monitor-mix position (e.g., proximity to the band's refreshments, quick exit if the audience gets rough), but very little advantage when judging the balance of sound heard throughout much of the audience. Listening a few feet from high-compression horns can only be appreciated by devoted (possibly deaf) fans. This is not the place to judge the sound heard by most of the audience. Balancing the mix of stage sound with house system sound is nearly impossible from this location (unless you work with Philip Glass...).
Front of the Balcony: After those last two suggestions things are starting to look up. You have finally been offered a mix position you can work with, right? Well, even if we ignore the issues of lugging the equipment up those stairs and actually finding a way to make your mic snake reach this location, the problem of system coverage still remains. Is your sound system configured to give the exact same quality and level of sound in the balcony as on the main floor? If not, why have you been cheating the listeners in the cheap seats? Reconsider your system layout or buy some more gear. If your system does offer consistent sound throughout the venue (and why not?), then you can accept the front of the balcony as a reasonable compromise.
Off to the Side of the Room: This location has some of the deficiencies noted above in the discussion of corner locations . Obviously, if you depend on stereo effects then you should design a sound system that can produce these effects even in the worst seats-if you are going to mix the show from there. (You should have considered doing this before incorporating the stereo effects into the show anyway.) This is outside the scope of this article, but suffice it to say this is possible. It does, nonetheless, require additional loudspeakers and signal delays. If you are simply balancing an overall mix, then this location may work. Be wary, though, of any particularly loud and directional instruments (guitar amps, big keyboard rigs, etc.) that may not hit this location as much as the rest of the room.
Center of the Main Floor: This is perhaps the favorite location for most people that mix house sound. The best seat in the house-where not only is the balance of stage and system sound at its best, but the sight-line to the performers is also excellent. Of course, you now must be on your best behavior (or at least fit in with the audience) and try not to block the view of those seated behind you. This will mean reconfiguring your effects racks to rise only to seat height instead of the six-foot tower you use in the back of the room. There is one other consideration. The center of the venue is often called "Power Alley" because of the build up of bass from the two loudspeaker stacks on each side of the stage. Unless you are mixing on a more esoteric system with left-center-right loudspeaker arrays and carefully placed mono subwoofers, the Power Alley problem can be significant. Still, it's a location worth considering unless you are in the middle of a long row of continental-style (continuous) seating and want to be able to come and go after the audience has been seated.
Off Center of the Main Floor: This is the second-most favorite mixing location. It has the advantage of not being in Power Alley (this is wavelength dependent and therefore relative), but can be in an area of bumpy frequency response due to the same effects that created Power Alley. Now you are in the area of destructive interference instead of summation. The sound from each loudspeaker stack (again, we're just talking about the simple left/right stack) is arriving at slightly different times and so sounds that are common to both stacks (panned center) will interfere with one another. In spite of that problem, this has always been my preferred mixing location. It is usually at the end of a seating row offering good access. Listening to the show from slightly off-center allows you to really hear the show the way most of the audience will. After all, wasn't that the whole point of mixing the show from the house?
