Get Set for Great Sound by Stu Chisholm

September 15, 2012 by Stu Chisholm

Back in the March 2011 issue of Mobile Beat I outlined the basics of speaker placement and how a room can affect sound in an article called “Location, Location, Location.” I spoke of how echo can sometimes be cancelled out by simply angling speakers toward an imaginary point on the opposite wall, how subwoofer power can be maximized with acoustic coupling, and how all speakers can sound better by paying attention to the basics of sound.

Even though I’ve written on some other fairly controversial topics, this article is the one I still receive more calls and e-mails about than any other! So today I’d like to take a moment to apply these basics to a few typical mobile setups and show how I solved some of the sound problems encountered with each.

SMALL INDOOR VENUES: AVOID BIG FAIL With smaller parties ruling the mobile roost in the lower Michigan area, I’ve seen a whole lot more of the smaller venues recently.

While these venues, in general, are usually the easiest to play, they can also be the hardest in which to correct sound problems when they rear their ugly heads.

If you’re like me, you usually arrive at the hall to find an area that has been set aside for the DJ. Assuming you’ve discussed your concerns with the venue staff ahead of time and there are no obstacles or other placement problems, then you start out with your set-up routine, placing your gear for maximum visual impact (or perhaps the opposite, if you’re trying for a more discreet “white glove” approach). This becomes our first area of compromise: appearance vs. good sound. What looks good to the eye doesn’t always sound good to the ear. Before cords are taped down and the rig dressed up, this is the time to fire up the system, put on a familiar piece of music and let your ears be the judge. Even if you plan on using pink noise to create a sound profile, do an “ear audition” first. There is no better piece of test gear than the human ear.

The upside of the small venue is that echo is seldom a problem. The bigger enemy is the unnaturally boomy, brassy or tinny sound that can result from speakers being packed too close together. Too much bass? Just move any subwoofer(s) away from the corners and walls. Each surface you move away from drops the perceived volume by half. High/mid cabinets on tripods should have a bit of side-to-side latitude to move just in case there’s any frequency cancellation happening. You can actually seIssue 144-055e it by using a spectrum analyzer. Run the pink noise first on one side, then on the other, noting the level of each frequency. (Be careful!  Pink noise at high volume will kill your speakers.) Then, bring up both together. If the analyzer shows a drop in any frequencies, you know you have some speaker moving or EQ tweaking to do.

NOT A COMMERCIAL…REALLY

While I’m normally not one of the Bose brand choir, I must say that their L1 Line Array speakers are ideal for a smaller venue, not to mention much easier to make “vanish” into the background.

Many of the frequency cancellation effects and coloration issues are eliminated or minimized due to their construction. Looking a bit like a pole, you can even use a single speaker for those really tiny venues. Their B1 bass module should suffice for most small events, but I tend to prefer a more traditional subwoofer, such as a Mackie or my old Yorkville standby, when the guest count rises.

LARGE INDOOR VENUE: SPACE CASE

When the room expands, so must your sound. There are two common approaches:

1. Placing bigger speakers/speaker arrays at the front of the house (on the stage area).

2. Spreading the sound through the venue using smaller speakers.

Assuming your event is something like a traditional wedding reception, your aim will be to focus the biggest sound on the dance floor, but you will also want everyone to hear your music and announcements everywhere in the building. I solved this problem by setting up my standard rig/speakers in their usual position next to the dance floor, treating it as if it was the whole building. Then I strategically placed a row of active speakers down each wall of the venue all the way to the back. They were linked by an improvised wireless system so that long runs of cable wouldn’t be needed. (See sidebar on page 22.) By aiming the front-of-house speakers toward a single point on the back wall and running the volume much lower on the satellite speakers (on their own output with a separate volume control), I could keep the volume at reasonable “talk” levels in the periphery even as the volume was cranked-up on the dance floor.

Another way to spread sound through a big venue is to hijack their own in-ceiling PA. Using a direct box, an auxiliary output on a mixer can be converted into a mono XLR output. You can then run plain ol’ mic cable to the nearest microphone wall jack. Once you convince the venue to turn on their system, your announcements and music will then be piped throughout the entire venue. This is especially helpful if the venue’s system feeds the bathrooms and lobbies where bridal party members tend to gather. Just take care when you do this, because most 70-volt in-ceiling speaker systems are not made for dance volume! Turn down the “house” when you crank up the dance floor.

MOVIN’ OUT!

When playing outdoor events, you trade one set of problems for another. Unless there are walls and buildings nearby, gone are the pesky echo issues. Gone are the boomy, muddy bass artifacts caused by the venue’s construction. Instead, raw power becomes an issue, since the outdoors tends to eat decibels for lunch.

There’s seldom such a thing as too much power.

THE GREAT OUTDOORS (SMALL GROUP)

Parties held in tents can usually be treated much like those in a regular building, with the main exception being the lack of any kind of bass boost offered by the tent’s “walls.” Where a small single sub would normally do, you might decide that a second one, or maybe a slightly beefier subwoofer is in order. You’ll find that a tent without side walls may not seriously impact the perceived sound power under it.

Take away the tent and all of that changes. Even mids/ highs sound about half as loud as they did in the tent and bass becomes very difficult to hear. The issue of “throw” is now apparent; speakers need to be pushed twice as hard for half the sound. For the smaller outdoor backyard party, simply cranking up the power a bit might do the trick. Once again, though, I’m a fan of using more speakers rather than bigger ones. An extra sub and two extra high/mid cabinets should be able to solve most issues.

THE GREATER OUTDOORS (LARGE GROUP) When the wide open spaces get even wider and need to be covered by sound, your entire strategy might have to change.

Speaker cabinets that aren’t normally suited to indoor events because of their ability to throw sound now make perfect sense.

If you’ve ever been to an outdoor concert, you no doubt noticed the flying arrays and rows of bass bins designed to get sound out into a large area.

For the biggest outdoor parties we’re likely to encounter, DJs again can consider the same two strategies. If bigger speakers on the stage is your preference, then renting two or more bass cabinets such as the EAW SB1000 dual 18” concert speakers and four or more EAW KF760 3-way cabinets, not to mention a rack full of huge amps to push ‘em all is your best bet. Or, you can use the same strategy as described for the large indoor venue.

That’s what I did one summer when I was invited to act as the DJ and emcee for a huge car cruise. Classic cars would cover the entire parking lot of a strip mall, and the bar hosting the cruise wanted sound throughout the lot and spilling out onto the sidewalk and the street beyond. As I had done in the massive indoor hall, I put my main rig at the staging area near the bar’s entrance, where trophies and prizes would be awarded, and then positioned active speakers along the entire strip, out around the perimeter of the parking lot and along the sidewalk. It took a total of 18 active Mackie speakers, fed by wireless transmitters, their placement made just a bit easier because of the electrical outlets at the base of the lot’s numerous lighting poles which the bar owner made sure were turned on for the event. Anywhere you walked in the lot, there was smooth, even sound and even decent stereo separation! (And yes, before you e-mail me, I definitely had to RENT all of those Mackies as well as the extra wireless receivers.) It remains the largest cruise I’ve ever done by myself.

STANDING ON CEREMONY

Most mobile DJs have the occasional bride and groom ask if they can provide a PA system for their wedding ceremony, which is usually at a different location than their reception.

Again, the rules change because the goals here are different.

Even though these often take place outdoors, the concerns of ample bass and speaker throw are replaced by the need for clear announcements, multiple live microphones and a PA system that will not be obtrusive, especially if it is captured in photographs.

It is tempting to simply pick up one of the all-in-one PA systems such as the Peavey Escort or the Fender Passport, since the speakers and stands are small (and therefore discreet), and they can handle multiple microphones, which are needed during wedding ceremonies.

Truth be told, these are excellent for most small to mid-sized wedding ceremonies. Always concerned with better sound, however, I decided to build a ceremony system around a specific pair of speakers: the Mackie SRM-350s. These are a bit smaller than the SRM-450s used by many mobile DJs worldwide, yet have a surprisingly good bass response and a bit more power for bigger ceremonies. A small console containing a mixer, flash drive player and wireless mic 4-pack complete the system, supported by a keyboard stand. The system is all in black, and I also have a white drape and stand skirts, allowing it to blend into just about any décor. Set up in the back of the room or behind the wedding guests, the ability to be heard clearly but not seen satisfies the goals of a great wedding ceremony system.

GOOD SOUND AIN’T NO ACCIDENT… MOST OF THE TIME As much as we know technically, the real world often confronts us with exceptions to nearly every rule. The trick for the professional DJ is to learn as much about good sound as possible… and then be ready to adapt when circumstances show us that what we know doesn’t always work. The best data comes from experience, and I hope mine will prove useful to you and your business. If you have any real world knowledge on getting better sound that you would like to share, please feel free to send me your story (DJStuCrew@gmail.com) and I’ll include the best ones in future articles. Until next time, safe spinnin’!

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Stu Chisholm Stu Chisholm (45 Posts)

Stu Chisholm had been collecting music since he was about eight years old and began his DJ career in 1979. After much hard work, trial-and-error, and a stint at the Specs Howard School of Broadcast Arts, he studied the DJ arts with famous Michigan broadcaster, Bill Henning, at a local college. Stu interned at Detroit’s rock powerhouse, WRIF. To his radio and mobile work Stu later added club gigs at Detroit’s best venues, and voiceover work. He has shared his extensive DJ experience through his Mobile Beat columns, as a seminar speaker and through his book, “The Complete Disc Jockey: A Comprehensive Manual for the Professional DJ,” released in 2008.


Filed Under: Issue #144, Sound, Weddings