Behringer CX3400 setup

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Member Since: Dec 21, 2009

I'm just learning about crossovers so bear with me. We have a church system that's running mono from the mixer (thru EQ & compressor/limiter) to a QSC 2450 amp set to parallel the input to both channels. One amp output goes to 3 OSP SF15W main speakers (15" woofer and 72mm horn ) and the other channel to a sub, not sure of the details of the sub. No crossover.

We have a Behringer CX3400 crossover we'd like to use. The CX3400 has 2 way stereo, 3 way stereo and 4 way mono modes. I thought we'd just run the mono from the mixer into the CX3400, set it to 4 way mono and run the low o/p to the sub amp channel and the high o/p to the main speaker amp and set the crossover to about 100 or so.

The question is what to do with the Low Mid and High Mid settings and outputs? Can we just set the Low/Low Mid freq and send the Low o/p to the sub amp, the Low Mid o/p to the main amp and ignore the other settings and outputs? Am I even on the right track here?


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The Czar of BS
Since: Dec 31, 2007

Dec 21, 2009 06:17 pm

Sorry Tom.... Your not even close.

The setting that you want it in, is 2 way.

Your top box has an internal crossover in it. So, your sending the full range of information to it. Except for the information that is going to the subs.

Put it in 2 way, set the crossover point to about 125 hz, and you should be fine.

Now everything above 125 hz, will go to the tops. And everything below will go to the subs.

A 4 way crossover is sending very narrow bands of frequencies to each individual speakers in the system. That translates to:
Horn ( Usually a 1" Driver)
High/Mid (Typically a 6.5" to a 12" driver)
Low/mid (Most of the time, it's a 15" driver)
and Sub ( An 18" driver)

All of these drivers, are on one side of the stage. And have a separate amp for each driver. This is the type of set-up that we do for large shows. Such as arenas.

For your situation, you have a 1" with a 12" mid. This is feed by one side of an amp, due to the fact of the internal crossover.

The only other thing that you need, is an amp for the subs, being feed from your crossover. And life should be good.

Since: Dec 21, 2009

Dec 21, 2009 07:05 pm

Thanks, Rob. Actually, I WAS close at one point. My starting point was 2 way stereo with the highs going to the mains and the lows to the sub which is what you indicated. My problem was the manual seems to indicate that the CX3400 wants 2 inputs in either of the stereo modes. It doesn't look like there's a way to parallel the input. I got started down the mono path because that seemed the only mode that I didn't have to provide a signal on both of the two inputs. Is there a problem not using the 2nd input?

Thanks again.

The Czar of BS
Since: Dec 31, 2007

Dec 21, 2009 08:03 pm

No. Not at all.

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