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Need some tips on using Behringer Shark to fight feedback
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I also understand where you are coming from. I was a broadcasting major in college and have done many shoots where you have to roll with the punches.
Until you get the feedback under control, don’t use a compressor on the reinforcement mix. When the unit ceases to clamp down on the material, the feedback will come back with a vengeance from the newly-added gain.
Also, another potential solution might be to use a microphone with a Figure-8 pattern. Since there are deep, consistent nulls on the sides of the microphone, and very little bleed from surrounding sound sources, I think it may be worth a try. Just make sure that the other side of the pattern isn’t catching reflections from the top of the lectern.
Wolf
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Yah, here’s one of those penniless high school dropout dope smoking wannabes. Note position of his right hand:
James Cameron on set of Avatar -
Actually, I’ve got a couple of Behringer Sharks that I use with a Fender Passport sound system for meetings in hotel rooms up to 150-200 people.
That said, the Behringer Sharks are more trouble than they are worth. First, they are multi-function devices with a lot of modes and settings. And they have to be tuned to the room. Maybe if somebody was doing this gig day in day out, they would eventually learn to work the things. I have not tossed them out of my gear bag, but they simply never get pulled out and installed at shows anymore. Maybe if I had an extra hour to screw around with them, but considering I’ve usually pulled an all-nighter anyway, the Behringer sharks just don’t happen. They are marginal anyway. I’m more fascinated by their other features now; their feedback elimination is weak.
Back to basics:
Ty Ford and others here have given golden advice. The key is good mic technique.
My presenters use omni lavaliers. Once they amp up the volume in front of a live audience, it always works. Nobody I know believes in cardiod lavs, but it’s your money.
About good mic technique. Executives exist in a reality distortion field. When you say you have no control, this implies the executive holds your function in contempt, somehow implying that if the exec had a real audio pro, nature’s laws of physics would be suspended. Either get a new gig or go toe-to-toe and face to face with this arrogance. Sounds like you are dealing with a God complex, somebody who expects to roll forth heaven and earth with the sound of their voice.
Only their voice is not going to be heard without proper mic technique. If the President of the United States and Steve Jobs must both be wired or else speak directly into the mic, then your guys must do so also. You can look them in the eye and tell them this with absolute confidence.
After too many customer evaluation forms complaining about audio, I’ve had to get tough on our people. A major problem is non-professional talent who believe they don’t really need a PA at all, and treat the microphone like some kind of Harry Potter magic wand, a “talking stick” they hold when it is their turn to speak, to be held somewhere down around their belt buckle, with a thumb hooked into their pocket. One of our guys is a repeat offender for putting the wireless mic into his back pocket. Don’t know what they expect out of sound there, but it won’t be good!
One tip, though, other than “telling them how the cow ate the cabbage.”
There is no law written that says you must place the Fender Passport speakers to the left and right of the speaker’s podium as if you were setting up a home TV set. In most of my presentations, a large rear projection screen has center stage, with the presenter’s podium off to one side. I position the Passport speakers as close together as possible, cabinets side by side with front faces aligned in fact to reduce possibility of phase cancellation. But I setup the speakers on the side of the room opposite from the presenter. I also angle them away from the speaking position, to further reduce backwashing amplified sound back into the microphone.
There is no such thing as stereo audio in 99% of all sound reinforcement. If audio is right, nobody in the audience will notice there is audio.
The other thing to consider is positioning the Passport speakers forward of the presenter. Others here have said as much, but I tell people, “Feedback is due to the difference between the speed of light and the speed of sound.” Essentially, the audio path from the speaker’s mouth to the Passport loudspeaker occurs at the speed of light (electricity travels at roughly the same speed). The speed of sound, however, is vastly slower. So sound generated at the microphone comes out of the loudspeaker at essentially the same time. Once the loudspeaker converts the electrical signal into audible sound, however, the sound travels at a relatively leisurely rate through the meeting room. Feedback happens when the sound out of the loudspeaker reinters the microphone, then instantly comes out of the loudspeaker again. So you get an endless loop setup, first a little ringing, then an ear splitting howl.
That’s why I don’t think the Behringer Sharks are much good. They really don’t have much effect on feedback, but they can, with great care, be tuned to stop a bit of the precursory ringing. The Sharks are multiband, multi-frequency, which amounts to addressing the specifics of tuning — the exact frequency of feedback is affected by distance between mic and speakers, and standing reverberation waves in a specific room due to wall distances, etc.
So what if Behringer Sharks can notch these frequencies? This does not eliminate feedback, it only suppresses the early warnings of feedback. You can’t make a pig fly. An SUV is not a Porsche, even though the SUV does have stiff handling. If you make the mistake of thinking the SUV will corner like a Porsche, the SUV will simply flip and roll with no warning. Consider the ringing sound that precedes full blown feedback to be “body roll” — audible warning that things are about to go south. At that point, you are either going to be forced to gain down the volume, or else finesse mic placement.
The mixer is critical
When running multiple microphones, a simple mixer like my Mackie VLZ-1402 adds a critical additional safeguard against feedback. You cannot allow open mics. In our case, we have 3 people working the audience with wireless mics for Q&A, a wireless mic at the podium, plus lavalier body packs on one or two presenters.
Mixing can be a little hairy because I am usually the man behind the curtain. So I stick my head out during Q&A! I leave the VU channels gained up. Judicious use of the Mute and Solo buttons makes it easy to switch mics completely on or completely off as needed.
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Updating this thread as I have used the DSP110, then the nearly identical FBQ100 for years. First as a very affordable noise gate & compressor for several different ham radio rigs. Then more recently we were setting up for a remote interview and found a set of squeals we couldn’t remove easily. Rather than kill the audience participation mic, I had an FBQ100 with me and set this up:
We have had a great deal of success and carry either a DSP110 or FBQ100 with us for these remote interviews. We know FB suppression shouldn’t be needed, but often it is just not possible to reposition speakers and mics enough, so hit the FB suppression button and the monitor output is clean. We also have used a 2nd DSP110/FBQ100 for noise suppression and elementary compression on the both input mics after having success suppressing FB on simple remote monitors. The compression settings minimize post-processing of the audio.
Another downside, though is that the JK Audio RemoteMix does exactly that and we have no track separation between telephone audio and local. For this application, that is acceptable as the RemoteMix is far superior in audio quality to the previously used custom boxes with audio transformers!
This setup works well. We could really use some advice on a battery powered equivalent to the DSP110/FBQ100 for better portability. Everything else is battery powered in the diagram above.
Best, Mark
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