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.

[Jack]

You might also notice it sounding kind of muddy as you're essentially getting 'double' signal from (guessing) 100-300Hz where both the tops and the subs can give meaningful reproduction. A cut in that range might help clean things up. 

 

Edit. Just got back to the thread and noticed this has been mentioned... 

Edited January 23 by Jack

[Phil Starr]

I ran a PA with a couple of Titans and some JBL subs which had no crossovers for a while. this was for an open mic/jam session which didn't really merit my taking my 'big' PA which at the time wouldn't fit in my car anyway.

 

The way I set up was to roll the bass off from the Titans which have a tone control, I notice the bass is actually boosted on yours but that may not be your gig setting. That gave a fairly thin sound from the tops but a 6db cut below 100Hz (bass control at 3 o'clock will give roughly that.  I then brought in the subs gradually until I got a balanced sound from a bass and the kick drum without making the bass overblown. Tuning by ear like this isn't ideal but you can make it work, none of the bands noticed anything 'wrong' with the PA and the overall band sound was great. Rolling off the bass from the tops will reduce the cone excursion which is one of the advantages using subs gives you. -6db is 1/4 the power going to your tops freeing them to go louder and less distorted for the rest of the frequency range.

 

Buying a crossover before  the signal reaches the amps would be better but it might be more cost effective to sell your subs and amp and save the cost of a crossover to buy a sub. A single wharfedale 15" sub would probably match your two Peaveys and has a stereo crossover built in so you can run the PA in mono or stereo with a single sub. The Wharfedale EVP15 sub weighs a ton but is relatively cheap on the used market and will be good with your Titans. I've used that exact set up in the past and still have two EVP15 subs. Other makes would probably work well as well. The Wharfedale T-sub AX is the same speaker as the EVP but has a plywood box and class  D amplification reducing the weight from 43kg to 27kg so if you see one of those used then go for it

[Suburban Man]

On 22/01/2025 at 13:48, missis sumner said:

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)

Can I assume that you are mixing in mono? If so, and you are feeling creative (you may not be!) you do have the option of running the active full-range speakers from the two left outputs and the bins from the two right outputs (just a jack-XLR adaptor or similar cable required)

That way by shifting the pan control left or right you can alter the amount of any channel that is running to either set of speakers.  Full left = Titans only, Full right = Peavey bass bins only, central = 50/50 split

It would enable you to run the bass-heavy channels more into the bass bins and vocals (for instance) only into the full range Titans.

Not a perfect solution at all, but would cost less than a tenner to try out...

[missis sumner]

16 hours ago, Suburban Man said:

Can I assume that you are mixing in mono? If so, and you are feeling creative (you may not be!) you do have the option of running the active full-range speakers from the two left outputs and the bins from the two right outputs (just a jack-XLR adaptor or similar cable required)

That way by shifting the pan control left or right you can alter the amount of any channel that is running to either set of speakers.  Full left = Titans only, Full right = Peavey bass bins only, central = 50/50 split

It would enable you to run the bass-heavy channels more into the bass bins and vocals (for instance) only into the full range Titans.

Not a perfect solution at all, but would cost less than a tenner to try out...

 

That sounds very creative!  Thanks for the suggestion - we'll try it!

[Chienmortbb]

On 22/01/2025 at 14:06, David Morison said:

 Thomann Mini DSP.

I have the powered version with a 4x50 watt amp included. It is very easy to use, has every feature I can think of and includes a signal generator. The UI is Windows only and looks dated, but it is funtional.

[Chienmortbb]

There are three units in that Thomann DSP range. The middle one, price wise, has XLR inputs and outputs plus three recallable memories. I think that is worth the extra cost https://www.thomann.co.uk/the_t.racks_dsp_4x4_mini_pro.htm

[missis sumner]

On 25/01/2025 at 19:46, Suburban Man said:

Can I assume that you are mixing in mono? If so, and you are feeling creative (you may not be!) you do have the option of running the active full-range speakers from the two left outputs and the bins from the two right outputs (just a jack-XLR adaptor or similar cable required)

That way by shifting the pan control left or right you can alter the amount of any channel that is running to either set of speakers.  Full left = Titans only, Full right = Peavey bass bins only, central = 50/50 split

It would enable you to run the bass-heavy channels more into the bass bins and vocals (for instance) only into the full range Titans.

Not a perfect solution at all, but would cost less than a tenner to try out...

 

Your solution worked!  We went in to our rehearsal room today, and set up all our own gear.  The L/R channel fix worked a treat!  We had a really good sound and plenty of volume in the room.  Thanks so much!