Divide and Conquer: PA Configurations – Jake Feldman

August 29, 2012 by Dan Walsh

During the years I’ve been in the business, I have seen a lot of people do a lot of strange and even dangerous things when it comes to sound. Most of the time, those errors are a result of ineptitude when it comes to the science of sound. Commonly, DJs mistake systems for “all-in-one” solutions when they may actually work best for only one application. They fail to realize that perhaps better tools exist that would accomplish the task at hand more efficiently and might even (gasp) sound better.

Let’s take a fresh look at some approaches to sound from an event-based perspective.

WEDDING CEREMONIES

Although it’s usually not the responsibility of the mobile DJ, you will inevitably be called upon to provide sound reinforcement for the pre-party portion of a nuptial event, especially if the ceremony is not being held in a house of worship. Sound at a wedding ceremony is two parts audio, two parts aesthetic. Sure, everything needs to be heard, but you also DO NOT WANT your system to be seen in the happy couple’s photographs. Unless they really love the black drape and road-case look, or were on the road crew for Skynyrd in their wild, pre-marriage, oats-sewing days, get the gear out of the way.

At the bare minimum, a service provider for a normal ceremony should have the following items to produce sound: a live sound mixer (DJ mixer will not do) with at least six channels of XLR Mic/Line input, two wireless lapel mics, a wireless handheld mic, two 1/8” adapter cables (for MP3 players), and a reliable CD player. Of course, it would be ideal to have two identical systems, with one as backup.

Of course, you will need at least one speaker to make sound, and I would recommend a powered speaker of small size (with an 8” or 10” subwoofer). This speaker would preferably be pole-mountable. Sound clarity is also something to think about, which is why I would buy a product from a reputable company and test the system out before you decide to hone your skills on a real (live) wedding.

WEDDING RECEPTIONS

These events by far are the ones that mobile DJs are known for–and yet some DJs get the idea of sound for a wedding reception way, way wrong. It does not involve the same kind of racks and stacks necessary for the Rolling Stones to take the stage; it should be something that keeps a low profile and sounds fantastic at the same time. And we’re not necessarily talking about the latest and greatest; we’ re talking about the tried and true. Until someone proves me wrong, I say you can’t go wrong with a high-quality pair of 12” or 15” powered speakers on tripods for a wedding reception. I know what you’re going to say–that the latest thin line array systems are the way to go, but remember I am all about sound quality first, looks second. And by the way, leave that big burly subwoofer at home–most grandmas don’t need their fillings shaken to enjoy the music.

For larger receptions, two more powered speakers may be necessary, and I have performed at up to 600-guest weddings with just four 12” powered speakers; the key to success being proper placement and knowing when to focus musical energy on the dance floor. Going down the list, the minimum required to properly make sound at a wedding reception would be a pair of 12” or 15” QUALITY powered speakers, a RELIABLE wireless microphone, your DJ mixer and your media player. Of course, make your “kit” look tidy by keeping your cables neat, masking your equipment with a facade, and keeping as low of a profile as possible.

MIDDLE SCHOOL DANCES

Here’s where we separate weddings from everything else a mobile DJ does. First, it all depends on the attendance and size of that particular middle school. I would arrive with no less than two 15” powered speakers and at least a 15” powered sub. If you must, you can be completely archaic and use unpowered speakers and sub(s) for this application (notice that’s the first time I’ve said that in this article).

The idea of a middle school dance sound is completely opposite of a wedding. At a wedding, especially during the dancing portion of the evening, the sound needs to be centered on the dance floor area. At a middle school, typically the sound needs to be projected to the whole room, because the whole room is a dance floor.

HIGH SCHOOL DANCES: LESS THAN 500 ATTENDEES

Think of these events as what they are–overgrown middle school dances. Sure, you need more lights (a different article altogether), and yes, you need to play sometimes drastically different music. But, the sound setup is similar. The minimum I would use would be two 15” full-range, high-quality tops, and two single 18” subwoofers paired (or a dual 18”) in the center of the stage or in the front of the DJ booth (pairing gains 3db of low-frequency boost per coupling of the same subs). It also should be noted that one should never mix types of subs (front loaded, folded horn, side loaded, or cardioid) or sizes–as massive frequency cancellation will occur and you will be left with massive dead spots on your dance floor and intense spots elsewhere. I’ve been at scene of that kind of disaster, and believe me, it ain’t pretty.

HIGH SCHOOL DANCES: 500 TO 1,000 ATTENDEES

For the bigger HS events, you should ditch the small-scale cabinets and bring in the heavy artillery. Ponder this: If they can’t hear you or feel you, you could be the best DJ In the world, but you will never get a return engagement at that school (the name of the game in school dances). This is where line arrays (real ones), tri-amped cabinets, power valleys, drive-racks, and power consumption issues come to the fore.

Especially important for this level of dance is the old adage: “If you can’t do something right, don’t do it at all.” I cannot begin to tell you how many schools have contacted us, and paid 3x what they paid their previous DJ, because the guy was a wedding DJ with a free Saturday but no clue about the gig’s real requirements.

This is also when you’ll find out how your placement of the “stacks” can seriously affect your event. The room’s natural acoustics can aide or hinder your sound. Rather than increase the length of this article beyond the printable range, I suggest you check out a book or take a class on live sound. (Stu Chisholm’s accompanying article on speaker setups is also a good place to start. – Ed.)

At the most basic level, I would suggest at least 10 watts of sound per person in attendance as a general rule of thumb. To make a long story even longer get, I would suggest the following to impress your clients with 500- to 1,000-person school dances: at least four high-quality, 1,000-watt-plus (RMS) tops (full-range), and at least four high-quality 1,200-watt or higher dual 18” or 21” subwoofers, in at least two pairs of two for maximum effect. Part of the experience—the “wow” factor, if you will–for these types of events is also the look of the system, which should approach the level of a small concert, in my opinion. This system would give you around 8,800 watts (RMS), which, if placed correctly, would be fairly burly sounding.

HIGH SCHOOL DANCES: 1,000+ ATTENDEES

Ah, here’s where many a DJ runs into trouble—providing walloping sound for 1,000 plus students without going into tons of debt and losing the gig due to overbidding. There are actually two schools of thought on tackling this, and both have their pros and cons.

Before covering them, first and foremost, if you’re not ready to take this plunge, don’t even try. A local competitor tried this and it hurt the company immensely. In fact, we now have the event and they are nearly out of the school market.

Once you’ve decided to try you can either rent the gear from a production house or own it. If you choose to rent, remember that it may cost you a bit more at first until you arrive at a point where your relationship with the rental house improves enough to offer you terms (net 30, etc.) or even below-spec pricing. In this case, typically you can either opt to set the system up yourself or pay the fee and have the professionals do it.  Either way, charge your client accordingly.

The next option, and this one is my favorite, is to purchase the system. Remember, you are making a 10-year purchase—that’s why the price tag is so high. But you can also rent out the system to other DJ companies who may not have the capital to purchase. It may be a dilemma, but the smart money is on purchasing. (I feel so Dave Ramsey right now.)

For these events, the 10-watt per body rule certainly applies, and I would consider the following minimum: six full-range cabinets of at least 1,200 watts each (RMS), and eight subwoofers at at least 1,400 watts each (RMS). This would bring your total watts RMS with this system to 18,400, which would accommodate 1800 students quite nicely (and require more than your mom’s station wagon to haul).

In any case, all that power means nothing if you don’t know how to properly use it. This kind of setup requires a serious grasp of proper audio concepts beyond the scope of this piece.

CONCLUSION

The bottom line is that sound is not child’s play. Unlike lighting, which has very few absolutes besides color temperature and hue, sound has a plethora of dos and a cornucopia of don’ts all ripe for the picking. Don’t leave home without first evaluating your system in relation to the type of event it’s intended for, and, for crying’ out loud, use the proper gear for the proper gig!

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Jake Feldman is Mobile Beat’s Gear Editor and Review Coordinator, as well as Production Manager for the Mobile Beat DJ Show.

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Dan Walsh Dan Walsh (89 Posts)


Filed Under: Exclusive Online News and Content, Issues from 2012, School Dances, Sound