Whether you’re a musician, a sound engineer or a major league baseball player, everyone has a bad day once in a while. But in these twenty-teens, technology has reached the point where there’s little excuse for bad sound. I just mixed a show at a major casino stop on the East Coast. Names and locations are withheld to prevent the guilty from personal injury and humiliation.
Both the casino and showroom are relatively new, and it’s obvious that a fair amount of money was spent on their construction. The showroom certainly didn’t lack for gear, with an Avid Profile at FOH and an SC48 for monitors. The system processor was a fine piece of gear — if you were wiring a restaurant. Club/showroom? Not so much. The loudspeakers were recent powered models made by a well-established manufacturer, and here is where things start to get ugly.
I have never designed a commercial loudspeaker, but I’m confident that most (if not all) major speaker manufacturers go through a lot of trouble to determine and share the manner in which their boxes should be deployed. One look at any company’s product data will reveal all the drawings you could ever need regarding power requirements, coverage, height, angle and the proper manner in which to hang multiple boxes. Manufacturers don’t want to suffer criticism for what boils down to operator error, and I don’t blame them.
The Problem
I wish you could have seen the flying junkyard that the install “engineer” passed off as a P.A. hang in this room. It was fairly obvious that the installers had no respect for the manufacturer’s design, nor did they have any clue regarding basic loudspeaker geometry. The main hang consisted of two clusters, one per side. Each side consisted of two large full-range boxes flanking a subwoofer, randomly pointing in haphazard directions. None of the boxes were flown to the same height. The outside box faced the side of the room (where there was little space for patrons), though at least it was aimed down toward the floor. The other full-range box was aimed toward the rear wall of the room, about 12 feet up — again, where there were no seats or standing room for audience members, and produced a nasty slap. Underneath the large boxes were several small fill speakers, placed with as much care as my nephew played with blocks when he was two. Come to think of it, my nephew was more careful about arranging his blocks. It doesn’t take a genius to understand that the audience should probably be within the coverage pattern of the speaker.
This sonic train wreck was amplified (pun intended) by the designer’s system processing, which featured the most obnoxious, bizarre sounding EQ curve I have ever heard, although it may have been appropriate for a car stereo competition. I haven’t experienced a P.A. system this bad since 1997, when I worked a dump in San Diego that shall also remain nameless to protect the guilty.
Problems and Non-Solutions
This system leaves us with two major issues: poor geometry and misuse of system processing. First the processing. So why didn’t I simply bypass that EQ curve or modify the crossover points on the system processor? Because the system processor was locked off by the installer and he would not release the code to the house audio tech (who really went out of his way to help me get a handle on this beast). Smoke was clearly coming out of my ears. The only thing I could say to the house tech was something like “I think you need to remind this #$@*#^ idiot that he works for you, not the other way round.” It was very clear that Mr. “I hooked up my Mom’s DVR and therefore I can design a P.A. system” never mixed on this rig, and I doubt he even listened to music over it (how he got the gig in the first place astonishes me). It was so wrong that I could barely wrap my brain around what to do with it. The fact that it was locked out was unacceptable. I did the best I could using EQ on the desk, but the bottom line is that — not only do manufacturers create great audio tools these days — they also take a fair amount of interest in making sure that their tools are used properly. If I had built these boxes, there’s no way I’d want anyone to hear this system. I’d be embarrassed. In addition to furnishing a plethora of tech data, I’d support the use of tools that ensure my products are properly used.
EASE of Use
One of the tools useful for P.A. system design is AMFG’s EASE: Enhanced Acoustic Simulator for Engineers (ease.afmg.eu). EASE is a suite of acoustic measurement and analysis tools that can be used to predict how a PA system will behave before it is installed in a venue. A CAD component to the software allows 3D modeling of a venue, whether it is closed (indoors) or open such as a arena or stadium; room models created in other CAD software can be imported to EASE, with ease. The software contains a database of more than 700 acoustic treatment materials, and by “assigning” such materials to the various venue surfaces, EASE takes into consideration the absorptive and/or reflective characteristics of the materials and their effects on room acoustics.
Given a relatively uncomplicated acoustic system (i.e., a human voice delivering speech to a person sitting in the audience), EASE can predict things like speech intelligibility and reverb time before the room has been built. Very powerful indeed, but as audio engineers we know that this type of unamplified acoustic system is rare — even for house of worship applications (when was the last time you mixed without a P.A. system?). And that’s where EASE steps it up another level.
More than a 100 loudspeaker manufacturer and engineers have contributed data for more than 3,000 different speaker models to the EASE open database. That data is not exclusive to “premium” speakers. There are EASE data profiles for simple and digitally steerable columns, line arrays, simple box loudspeakers and multi-way loudspeakers. This data is used by EASE to predict and analyze the performance of a given loudspeaker or cluster of loudspeakers in the room. A virtual sound system can be created, with control over parameters such as level, delay time, phase, and cabinet position across all three (X, Y, Z) axes. The resulting system mapping can include direct sound SPL, direct plus reflected sound field level, speech intelligibility, ratio of direct to reverberant sound, critical distance, arrival times, cabinet aiming, coverage, overlap, and other parameters — all of which greatly increases the likelihood of success in designing a P.A. system. A far cry from the room modeling software I ran on a Mac SE30 in the early 1990s (I’d go out for lunch after clicking “calculate”!)
When you combine software tools like EASE with hardware tools such as handheld laser tape measures, electronic protractors and advanced rigging hardware that in many cases allows speaker cabinet adjustment within 1-degree accuracy — there’s just no excuse for a flying junkyard.
