Karaoke Forums

I was just reading the new "Auto Tune" thread and it mentioned something else that reminded me of what I FEAR MOST- FEEDBACK.

I'm going to do my first real gig soon, in a 300 seat or so hall, and my friend, who's been around when I bring my karaoke setup around to friends houses for garage karaoke wants me do music and karaoke. I'm afraid my GTD audio wireless mics are gonna incur some feedback cause in Hawaii, we like to sing seated from our seats and sound will be directed to the back of the mics when the singers are singing. The mics have great feedback rejection in the past where I did small house parties/family parties/gatherings, again, with singers in their seats. There has been evidence of feedback in rare instances where the singer points the mic at the speakers by accident.

With this bigger gig, I'm gonna be putting out some serious SPL, I just want to make sure the audiences ears are protected if anyting happens. I just don't trust the general public with their knowledge of handling mics.

I'm looking at the Behringer Feedback Desroyer. Trouble is, I don't trust Behringer ever since the mixer I got from them went on the fritz and started making firecracker sounds through the PA. Almost broke a lot of family and friends' ears then too. I like to spend a bit more to avoild this being embarrased now, and nothing is worse then having unberable noise at high SPLs coming through the PA. Anybody got suggestions. I know there is also feedback rejection on the TC Helicon VoiceTone, which would be nice as you also have Auto Tune (Would help me a ton when I sing!). But I'm going to need 2 of these for both of the mic, so this may be out of the question as it'll be way too expensive. Please give me some suggestions.

One of the major solutions to each of the anticipated problems you list is making sure your system is set up with proper gain structure. With proper gain structure, your system puts out the most efficient sound possible, which equates to the most perceived volume at the lowest actual electric energy. With proper gain structure, your audience will have much less ear fatigue, even at higher volumes, and there will be almost no chance of feedback with proper mic technique. I can point my mics at my speakers at moderate volumes from about 10 feet away, and no feedback.

That said, you do still need to teach your singers proper mic technique. Even if they are in their seats, they really should always face the speakers. If you set up your lyric screen so they have to, that will take care of it most of the time. The mic has magnetic shielding that will prevent it from picking up sounds as long as the base of the mic is generally pointed in the direction of the singer. Then, of course, make sure they are holding the mic by the handle, instead of trying to be all gangsta by holding it by the ball.

Do a Google search for setting proper gain structure. It's one of the best upgrades you can do for your system, and it's completely free!

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C Mc
KJ, FL

I install the dbx 1046 in every system now. It allows me to limit screamers, boost whisperers, and eliminate feedback all in one unit.

http://dbxpro.com/en-US/products/1046

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-Chris

So others understand, the 1046 does not have feedback elimination circuitry like the Behringer FBQ1000 or Behringer Shark, for example. Compressing and limiting are separate processes. While a properly set compressor/limiter can help REDUCE feedback, it's not its primary function and should not be used as such. Even a simple 7 band eq on a mixer is more effective for eliminating feedback than a compressor/limiter. The 1046 will attenuate the entire signal rather than just the frequencies of the offending feedback.

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DJ Don

if your gain structure is wrong then you can end up introducing noises you don't want into your system. so make sure you setting you channels gain structures correctly as with any other devices your using inline with that channel and their gain setting on the device.

your behringer mixer must have been a powered pmp or pmh mixer. those are all crap. as i think all behringer powered mixers are crap. i've repaired several for people and when the amp dies i usually end up having to repair burnt traces where it's burnt a chunk of the circuit board away. stay away from behringer powered mixers.

feedback destroyers are just auto programming parametric EQ's.

if your system has parametric eq's lookup on youtube how to "ring out" your speakers.

when I "ring out" my speakers and stick the mic within a 1 foot of the speaker and wave them around and get no feedback at all.

and if your willing to spend a couple hundred for a compressor and feedback destroyer, don't!
replace your mixer with the behringer x air mixer and it has everything you need built in.

my new behringer xr12 air mixer has this feature and i love it! it has effects, compressors, eq's, parametric eq's. it has everything built in to the software. it runs from an adroid tablet or an ipad or PC. i can walk out into the audience and adjust levels while they are singing because it has it's own built in wifi.

my road case has gone from 4 components (mixer w/effects, eq/feedback dest, compressor, amp) to the xr12 mixer and an amp.

and for fun it has a usb recording port specifically record straight to a memory stick.

i posted a song in the showcase that i recorded on my first try out of the box. no edits or redo's it was a first shot deal.
http://karaokescene.com/ss/song.php?id=98355

I'm singing in my living room 5 feet in front of both speakers.

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It's all good!

Usually the only time I end up worrying about feedback is when I get a microphone cupper who covers the ports near the base of the head or when I try too hard to help a whisperer.

You have to figure out how high you can go and once you hit that point too bad.

Speakers out front of mics helps, but if you run a wireless good luck with that

Speaker placement & mic placement, proper gain & eq will go a lot farther than any band aid processor. If there is nothing to cause feedback in the first place, you will have nothing to worry about. Feedback eliminators exist for engineers that know nothing about setting up or extremely small rooms that nothing can be done in the first place.

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LIKE Lonman on Facebook - Lonman Productions Karaoke & my main site via my profile!

Well, maybe you're right as far as me worrying too much as my feedback issues in the past were minor ones... just beginning to feedback and not to the point where anybody has had to cup their ears from overwhelming sound. And the minor feedback situations were from singers walking to close to the speakers, so they knew to step back a little.

Getting a FB elimnitor will be more as an insurance against it, to guarantee no feedback the entire night.



Nah, the Behringer mixer's Effects circuitry blew. On the second use, it broke. I'm hesitant now to use Behringer stuff, but may have to with the Feedback eliminator as price will be an issue.

I have a Yamaha MGXU10 and 12, and been very happy with the fx and other features of it,... USB so you can go digitally from laptop to mixer. yada yada.

Like I said, obviously you can sing pretty close to your speakers and I have done so in my living room with bad acoustics and me sitting in the corner of room. Getting a feedback eliminator will be more for insurance. Just in case someone walks with the mic directly in fron of the speaker, stuff like that.



Ah yes, this drives me crazy. From "ice cream cone" to "ball cuppers" it just drives me up the wall. Maybe I'll just do some instruction right before hading off the mics. And yeah, obviously the mics have a cardioid type pattern, so most of the feedback rejectiion is in back of the mic.



Looks like the unit has compressors that help attenuate and boost. I already have 2 mixers with compressors- a Yamaha MGXU10 and MGXU12.

The DBX PA2 also looks like a great option, although it's more for sound management but also has feedbak suppression, but will be pricey with the need of another mic for that unit.

But hey, thanks for the great response and discussion.

Yes, I understand tech, so I do know what a feedback eliminator does- it attenuates the frequencies that are causing the feedback. Obviously, with an EQ, you can manually do this, but I want someting AUTO.

While most already know that proper gain structure will know that it maximises db before feedback; and obviously, speaker placement needs to ahead of the mics and not pointed at mics or walls, etc... THESE ARE SET THINGS.

But again, I will not have a stage setting set in the front where people will be singing with a set mike on a stand. The mics will be traveling around from table to table and the situations will be more DYNAMIC.

But like Lonman said, I may be overthinking this too much, and may not need one. I'm just worried about the high SPL as I'll be running 4 speakers and a subwoofer.

BTW, my setup currently, which i have had for a little over 2 years and was only inteded to be used at small family gatherings and at friends houses for singing in the garage-

2 Yamaha DBR10
Yamaha MGXU10 for portability, MGXU12 cause I needed a mixer in an emergency situation when the Behringer broke
GTD audio wireless mics.

I'll be adding 2 DBR12s and a DSX15subwoofer which should be coming in this week.

Anybody else got any other suggestions as far as what to add to the audio side of this rig?

This will be my first indoor and real "gig." A favor for a friend really, but I figure I'd take the advice, finally, from friends and family to take this professionally. I'm nervous as hell, as I'll be doing lights for the first time also, so....

Well just know that a fb eliminator can actually hurt the sound if it's relied on solely. The way they work is it senses feedback (basically senses the oversaturation of one frequency) and takes out small slices of that frequency until it's gone or reduced. Now on the flipside - if a singer is singing loud - it can give a false sense of frequency over saturation even though no feedback is occurring and the processor will pull slices of those frequencies anyway. Now since it does not reset itself, slices continue to be pulled out throughout the evening and the sound by the end of the night can be rather thin sounding. And if you continually reset it, it brings back all those initial feedback frequencies that were originally there and it will go through the process all over.
best way to avoid feedback is proper speaker placement, proper gain structure, and proper mic technique (which is hard to have with the typical singer. A good 31 band (or dual 31 band if you run stereo or both channels of the mixer) eq can go a long way as well for ringing out a room.

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Just curious how big is the 'indoor' gig. The 2 DBR 12 & 1 15 sub should be more than sufficient unless the room is just huge. Then I'd put the 12's & sub up front and run the two 10s in the back or halfway to the back to fill it out so you won't have to just crank the volume to reach the back.

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LIKE Lonman on Facebook - Lonman Productions Karaoke & my main site via my profile!

I've read how it works and understand it. I've read the reviews on the Behringer unit, and was wondering if it does reset once the offeding frequency is gone. It seems like there is a lock on mode, where it locks it. I'm going to have to call Sweetwater I guess, to see if there is a dynamic mode like I was describing above. Wouldn't that make much more sense though, if it "auto releases" the offending frequencies once they are gone? It also seems like the documentation is "difficult to grasp" from the reviews, so I'm hoping that those that did not like it had it in lock on mode, and those that did had it in some sort of dynamic mode.

Have you actually tried one?

As for ringing out the room, looks like the DBX PA2 will be the most discrete and easiest way to do it. But it'll be $450 with the mic. I can imagine me instucting a person to walk all over the hall while speaking into a mic while I fiddle away at the EQ. . And yes, I do know that the overloaded frequencies will light up with capable units. I guess that's the quesion now is EQ vs. DBX PA2, instead of the feedback eliminator. I do believe the DBX PA2 has some feedback eliminator circuitry also.



Here's some pics to the place:
http://www.yelp.com/biz_photos/hawaii-u ... 3CT1f6YUZw

I'd say roughly 60'x100'? It'll fit 300 people though.

Looking at those pics, I always imagined it bigger as I have been there multiple times, unfortunately, half the time hammered. .

As far as running the 10's in the rear or half way, the problem is that with you facing the stage, the left side of the hall is usually used for refreshments and "pupu." You can see in the first pic where the staff are standing- that's where the door is for the food as it's self serve. Traffic will make the wires a tripping hazard. But having the 10's in the rear or halfway back would be ideal.

I think I'll just run it evenly distributed along the front of the stage, with the 12's nearer center as the sub needs to be on the floor. One of the 12's will be pole mounted on the sub. The 10's would be to the far ends of the stage or slghtly past it. My position would also be on the floor slightly left/right of the tv, as I'll set up a tv on a stand in the center of the stage, but still on the floor. Everything's going to be on the floor and the stage not used. 2 reasons- sub sounds better on floor, and it'll look ridiculous with me front and center on that stage.

Apprecite the feedback!

http://www.soundonsound.com/sos/jun14/a ... -drpa2.htm

Here's a good review on the DBX PA2.

Most importantly, it highlights how the feedback eliminator portion works.

There are two modes, a locking one, that locks all the offending frequencies, AND A DYNAMIC ONE. Where, like I stated on my post above.

Quote:
The PA2 incorporates an automatic feedback suppressor (AFS), which can detect the onset of audio feedback at any particular frequency and then quickly apply a very sharp notch filter to attenuate it. There are 12 filters on tap, and each can operate in two ways — either as a fixed filter that, once set, remains in place until manually cleared, or as a dynamic filter, which is applied when feedback is detected during a live performance and has the option to automatically release after a predetermined time.

It may be users of the Behringer who don't like it may have it in lock mode and not in some dynamic mode.

Pros of PA2- Auto EQ of venue/room, little noise when EQing, feedback elimination. Versatile; can use active or passive speakers.
Cons- Price, learning curve?

yes i have used a couple different behringer FB devices.
deq2496
ultracurve 8000

the 8000 was a lot slower a capturing frequencies but did work.
the deq2496 is fast and all the other features it has are nice to have also

both have a 31 band stereo eq

but the deq2496 has more option like delay and compression. but i only used for the eq and the feedback.

my newest toy i purchased is a tc-helicon Perform V witch also handles feedback but it a single mic application.

in my audio engineering class each day first thing we talked about was gain structure and the path of audio from pre amp input to the main outputs. you need to learn proper gain structure! then you get into adding EQ's. 31-band eq's are nice but each slider is set at a specific frequency. with a parametric EQ's you can sweep to the exact frequency and adjust the width of the frequency to cover the area your having issues with.

say your FB issue is at 2.7K most eq's are 2.5k then 3.2k (that's a pretty big span across 2 controls). and your trouble freq is in the middle of that. sure you can decrease both the 2.5k & 3.2k and cover that area but that's the freq range for vocals. with a parametric EQ you can go to 2.7k exactly and then adjust the width of the freq 2.68 - 2.72k and get really specific to cut out that trouble some area. .5k compared to .05k using a parametric eq.

and that's what a feedback destroyer is doing. the negative is if it captures to many frequencies in close ranges then you will notice so losses depending where the problem is. my 2496 i think is set to auto capture 6 freq's then i had the option to program my own if needed. then if new FB pops in it will drop the oldest progam and capture then new FB. so it's always watching.

but since my audio engineering class and my new digital mixer i don't even use the 2496 anymore. just a mixer and an amp. and like i said earlier, i ring out the speakers and i don't have feedback issues anymore. i can walk up to my speakers and wave my mic's in front of them and they don't squeal.

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It's all good!

Thanks for the explanation! I didn't know that a parametric EQ lets you adjust to the freqencies you want to adjust. I thought they were all set to a specific frequency and you just adjusted those. Good info there.

I have some knowledge of gain structure, though I will reread more material on it as I can before the big day. There might be stuff I missed.

I'm leaning on the DBX PA2 route as EQing the room will be much simpler (automated), and it'll have dynamic FB rejection. There are used DBX PX for half the price, but the white noise to sweep the room I think will be a deal breaker for me; Buying an EQ will bring me halfway to the DBX, so I might as well go all in I think.

I owned and used that unit. Trust me, it doesn't reset.

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LIKE Lonman on Facebook - Lonman Productions Karaoke & my main site via my profile!

Wow this is way to much stuff to read all in one helping.

Please check out the DBX GoRack. It's all you need to use as a permanent solution to your feedback issues. It's the best $99.00 you will ever spend.

Cheers!

I LOVE my DBX driverack. BUT the "auto-EQ" does a very crappy job. The unit does a GREAT job of condensing several utilities into one unit, and they are all extremely useful if you know what you are doing and set them all manually, but the auto-EQ is junk, and isn't going to get you where you want to go. If you want to take the time to learn how to properly manually set each function, definitely get a Driverack PA. If you expect it to do some automatic magic, you're going to be VERY disappointed.

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C Mc
KJ, FL

I did the Driverack in one system. Spent a lot of time using the system to set up a venue. When compared to the other venues we work, It didn't give me $500 per system in value. We manage feedback pretty darn well with just an EQ. I know the compressors/limiters have a different function, but we have less feedback on systems using the dbx1046 than those without and of course it is a compressor.

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-Chris

For all you BOSE haters out there - the T1 ToneMatch Engine has ParaEQ built in and it is programmable to each venue along with all the other EFX. But, it is matched to the Bose systems, hence the objections of many on this forum. One less piece of gear to carry around and the T1 TME can be held with a thumb and forefinger, ha !

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You can never argue with a crazy mi-mi-mi-mi-mi-mind ----B. Joel
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I became insane, with long intervals of horrible sanity ----E.A. Poe
I don't know, I don't care, and it doesn't make any difference! ----A. Einstein
Double bubble, toil and trouble ----W. Shakespeare & Walt Disney
I hate it when I get on FaceBook ----Me
Karaoke might be Groundhog Day ----?
Of All the Martial Arts, Karaoke Inflicts the Most Pain ----?

I'll lay off the obvious "your mom" joke here

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C Mc
KJ, FL