Quote:
Originally Posted by MichaelJHuman /forum/post/20897834
Not being a PA expert, I am confused why you would be using subwoofers and speakers with 15" drivers. Isn't that a bit of overlap? What's the standard for mid/high cabs in pro audio?
Most PA drivers don't dig down incredibly low (to get an example, grab your favorite modeling software, and put any of the Eminence 12 or 15" drivers in, they'll usually hit f3 at around 50hz), and even if they do, you want the overlap for re-enforcement - just to get the SPL target. Having a pair of 18" subs mated to a single 2x15 cabinet is not all that uncommon depending on the size of the venue. Generally using a single 15" driver and a horn, something like the JBL Eon, will get you that "megaphone" sound unless the level is fairly low and the room is fairly small.
To the OP:
I'm not an expert on this either, but I would suggest two things:
1) Use one amplifier per one or two speakers, not one amplifier for all four; you'll get more juice into each speaker which can mean higher output.
2) Determine if you really need four speakers.
You'll probably want an active-crossover to separate the subs from the mains, Behringer makes some affordable units. I'm sure you can get nicer boxes from dbx, BBE, etc.
I'd also make sure whatever speakers you get, you get all-weather covers for, if you're going to be playing outside.
Finally, if this is a mobile application, I'd strongly consider active speakers - Mackie or JBL should be fine, you'll just drive your board/mixer's output into an active xover, and drive that into your speakers. Any EQ/effects stuff will go in between the xover and the board. No heavy amps to lug around. However, if mains power is a concern, amps may solve that (as it centralizes your power needs) - ultimately weigh your options.
I'm sure any of the pro PA/broadcast guys will probably have some more refined and specific ideas.
