I'm reading the manual for a Behringer Feeback Destroyer and I'm scratching my head at this section about connecting it with the mixer...
Read Section 5.2 and look at Fig 5.2 (please!)... (on page 10)
http://www.pdf-manuals.com/pdf/behringer-feedback-destroyer-pro-fbq2496-feedback-fbq2496-b-h-38973-user-manual.pdf(I tried to post a picture of the page but I'm on an iPad and wasted the past hour twatting about trying to get a direct jpg URL out of a Flickr image before giving up!)
As luck has it, the mixer they've used in Fig5.2 is the exact one we have.
I get the explanation about using it with the mixer subgroups and how to feed the output of the FBQ2496 back into the mixer via an unused channel strip - IF your mixer doesn't have any subgroup inserts (ours does not). BUT... what's doing my head in is Fig 5.2!!! It's showing insert leads, one coming and going to/from a channel strip, the other where the subgroup
outputs are located on that (our) mixer. There are no subgroup inserts, so WTF is that insert cable doing on the right??
Also, what the hell are the mixer main outs doing going into the side of the FBQ2496????? There is only L & R inputs and outputs ? That illustration has SIX connections to it!
I'm wondering if they are just using that particular mixer as an example of "a mixer" without realising that the one they've used doesn't have any subgroup inserts, and that the main outputs are supposed to go to the power amp above, which isn't connected at all??
Donald Trump needs kicking out of a helicopter
Offset "(Emp) - a little heavy on the hyperbole."
Comments
The other thing they don't tell you about the FBQ2496 is that it comes set from the factory in graphic eq mode!
This defeated myself and 2 BBC sound engineers!
If you had inserts on the main left and right or subgroups you could use it on those but there's no advantage to doing so if your using it for global FOH correction
Offset "(Emp) - a little heavy on the hyperbole."
It's just that diagram - what they've drawn is impossible with the mixer they've used in the diagram and the main-outs are going back in to the FBQ2496 - which is also impossible, as you've already filled all the sockets on it anyway, as well as being logically incorrect. I'm pretty sure he diagram is wrong, after sleeping on it, but I just wanted to check in case anyone else disagreed.
Offset "(Emp) - a little heavy on the hyperbole."
As for the diagram in the manual, Behringer support have just confirmed they've got it wrong. The main outs should be going to the power amp in the drawing and the placement of the Right channel insert is misleading.
Brownie point for me!
Offset "(Emp) - a little heavy on the hyperbole."
I would do the lead vocal to one ch of the DSP and all the backing vocals to another if you can (spare aux and input chanels being the limiting factor). That way the keyboard players cheap mic badly placed won't hack holes in the freq response of the lead singers tone which will just be cut by it's own filters. Does that make sense?
Also: for heavens sake don't use more than two or max three auto filters on each chanel of the DSP, and once you've sound checked and rung out the system change them from auto to fixed to lock the settings and turn the volume down a touch for a nice stable decent sounding rig. If you leave them in auto they keep deepening and widening the hole carved in the frequency response making the whole thing seem quiter by the second set! Used correctly they can be useful, but over used or badly used they will make the sound awful and progressivly worse as the night wears on.
Offset "(Emp) - a little heavy on the hyperbole."
In the 70s and 80s a 32 band graphic was the best tool available to handle the problem unless you had a bunch of parametric eqs and knew how to use them! But as a valve amp loving guitar nut I have to admit in PA audio, digital is king. Big learning curve but Oh so well worth the benefits.
As tempting as it is to buy racks full of Behringer outboard (I see a lot of this with hobby PA) it generally causes more problems than it solves. With decent PA. correct mic placement and speaker placement you should be able to achieve more than sufficient gain before feedback without any feedback destroyers etc
If you do like playing with a lot of toys then your average entry level digital desk has everyone you need and non of the hassle of patching in .... plus you get iPad mix ability, IEM phone control, multitrack recording etc ..... Trying to take an old analog mixer and a bunch of outboard to achieve the same level will probably work out more money than buying a QU-SB or similar
Also put everyone on the same vocal mic, your life will be considerably easier.
Offset "(Emp) - a little heavy on the hyperbole."
Give me a Lab Gruppen PLM ticking over into Radian/EAW Micro wedges and well placed Beta 57a mics and you can have loud and clear stage monitors and not resort to outboard processing. But thats enough capital to buy a family car.
I've done gigs in the kind of rooms you describe, With no graphic etc when i was younger, fortunately its not something I have to do anymore. As you say the key to the feedback (fidelity)destroyer is probably setting it up properly. I Don"t know how he sets up his speakers but if he's getting feed back from FOH. I would suggest theres an issue with gain staging or speaker placement. Any way I would suggest the following:
Start with graphic flat
Engage hi pass filter @120 hz ish possibly higher, depends on singer
Get said singer coming into console with channel PFL'd. Aim for a level of around +3/+6Make sure their providing you with a level close to the one they'll be perfoming at. not mumbling 1-2. Bring fader up to 0db.
Is there feedback? If so bring fader down a touch, until feedback stops. Now go through the graphic and Boost frequencies where you think the problem is if it starts to feed back again then you're there! try a 3db cut then bring fader back to Zero.
If you're not sure where to start, Crossover points and Octaves/harmonics from there ie if the horn crosses over at 1.6k have a look at 12k/6.3k.3k/800/400/200.
Mute Keyboard players Mic until he gets the same one as everyone else. Or hack the life out the channel
Other feedback creators cupping mic, pointing in wedges idiocy in general. Also you can use the subgroup to get more level with less feedback. YMMV