Help please - Using passive bass bins with active speakers

[missis sumner]

Firstly, apologies.  I'm very inexperienced with this PA set-up malarky, so I'm sorry if what I'm saying makes no sense.  I've only just been dumped with it after our keys player was fired, lol.

 

Is there anyway we can connect our PASSIVE bass bins (Peavey HISYS 115 XT) to our ACTIVE PA speakers (Wharfedale Titan), so that the output from the bins is a "high-pass" - i.e. so the bass bins take care of the low frequencies and the normal PA speakers take higher stuff?

 

We have a Wharfedale R-2004FX mixing desk, with 4 main outputs on the back - a pair (L & R) of XLRs and a pair of jacks (L & R).

 

At the moment, we are taking the XLRs outputs from the desk to the PA speakers (L & R, marked with yellow and white tape), directly, because the speakers are active.  We are then using the jack outputs from the desk to run to a power amp (sorry, don't have the make, at the moment, but marked with green tape) and running the signal from the power amp to the bass bins (marked with red and blue tape(not shown)).  Thus the bass bins and the PA speakers are both getting the same signal (main output from the desk - just that one is amplified and one is not).  I'm not even sure we're supposed to be using the outputs from the mixer like that...

 

Can we use the outputs from the PASSIVE bass bins (marked "HI-OUTPUT") to run to the ACTIVE speakers?  I've attached photos of some of the connections, I hope it helps?

 

Thanks if anyone did manage to make it through this post.

[David Morison]

Short answer, no, unfortunately it wouldn't work like that.

 

Why - because the high pass filtering in the Peavey bins occurs after the signal has already been amplified, meaning you'd be passing a full power signal to the input of the Titans, which they very much won't like.

 

The right way to do this is to run your signal from the desk to an active crossover, which splits it by frequency and gives you separate outputs to feed one set to the Titans and another set to the amp that's driving your Peaveys.

 

The modern way of things (that gives you maximum control of what goes where) is to do it digitally - entry level units start around a hundred quid: Thomann Mini DSP.

 

For similar money, you can get new, analogue units that offer less control, or if you really want to save the shekels you could look for second hand rack gear. Behringer, Peavey, dbx have all made relatively affordable crossovers that should be findable for 50-100 s/h with a bit of patience.

 

HTH,

D.

[missis sumner]

Wow, thank you for that super fast reply!

 

I take it there is no obvious problem with what we are already doing, though, apart from sending bass frequencies to the Titans (which they seem to cope with quite well, when I do send some bass to the desk).  The only reason I am sending bass to the desk is for monitoring... which will probably be my next question. lol

[David Morison]

No worries, you're welcome.

 

Running as you are isn't going to blow anything up, but you're not getting the best out of your system as-is for sure.

At the moment, the Titans and the Peaveys are both getting fed the same signal, so they'll be overlapping each other. That usually doesn't sound as good as separating them so that only one type of speaker covers any given part of the audio spectrum.

 

Putting in a crossover would take a load off the Titans by filtering out everything below a set frequency (lets assume 100Hz for the sake of the example), meaning they do less work and (if need be) could maybe be pushed a little louder.

It would also ensure the Peaveys are only trying to reproduce content below that frequency, meaning they're less likely to contribute unwanted muddiness in the (low) mids.

[missis sumner]

Thanks again.  That's what I'd guessed.