I’ve been researching: How do you do pro audio for a Fourth of July Parade? In this case, we’re trying to give a bunch of dancers some dancing music and share that music with the audience, but we could be playing music on a float or a trailer. I know lots of churches who are involved in parades nowadays, and their entries always involve music. How do we make parade music so that everybody can hear it, and so it doesn't sound like garbage?
We’ve all seen the little battery powered systems; they’re great for a small group in a quiet environment, but they aren’t enough for sound in a parade: the high school marching band two blocks away will overwhelm it. Let's save these for mission trips or fellowship halls (they're pretty good for that!).
I consulted with Fred Tomke an engineer at QSC Audio. Fred knows his stuff: he’s been using his own K12 speakers on top of a bus in his own local Fourth of July Parade for a few years. OK, Fred, what do I need to power them properly?
It turns out that the only thing you need is a competent inverter for the vehicle. He uses a “basic 800 watt” inverter to power his (2) K12 speakers (1000 watts each), a small mixer, and a CD player. He says he’s never run out of headroom. “The secret is in the power supplies on the speakers: they’ll handle anything from 85v to 240v.”
To connect multiple devices (like the mixer, CD player, and multiple amps), just use a power strip. And we ended up using the smaller, broader-dispersion K8 speakers on this project: The smaller size made it easier to load onto their minivan’s roof rack, and the 105º dispersion pattern means more people alongside the parade route will hear it, even if you lay the speakers on their side (as any sensible minivan driver would do!). It still has the same 1000 watt amp built in, so “loud enough” is not an issue.
The little JBL EON210P system will also work nicely in this environment: a little poweredmixer and two 10” main speakers.
There is one important detail: don’t use an inverter that connects via the vehicle’s cigarette lighter. That lighter is limited, typically, to about 5 amps, and you’ll pretty much need all 6.7 amps that an 800 watt inverter can provide. Instead, use one of the inverters that connects directly to the vehicle’s battery, or extend to the battery with 10- or 12- gauge cables.
Oh, and make sure you vehicle is running. This kind of power consumption will drain your battery pretty quickly.
With this kind of setup, you can get loud enough that the parade officials will come tell you to turn the music down! Or you can use this system for your concert-in-the-park after the parade!
Happy Fourth of July.