posted
Feedback is caused when an audio input such as a microphone or guitar pickup "loops" it's signal repeatedly through the amplification. Too much volume on your source input (mic,guitar,etc..)can cause feedback OR being too close to the output speaker. Various frequencies can can feedback at different volumes. It's been my experience that midrange frequencies tend to be the main culprit in mic feedback, therefore, my graphic EQ has a "smile" on it. Low frequencies up, progressivly lowering throughout the mids, then back up at the highs. This setting , for me at least, gives the loudest volume without in fringing TOO MUCH on table conversation (mid range frequncies are much the same as human speach). It also keeps my mid range feedback to a minimum (if not non-existant).
And, if all else fails, get a Feedback Destroyer. Mine works well, for the most part, even though I have to reset it periodicaly due to it's suppresion of the desired frequncies.
------------------ The K-Wolf, Daron
Posts: 490 | From: Irving, TX. USA | Registered: May 1999
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Why would "cupping" your hand over the mic cause feedback, or lowering it towards your belly? A KJ I know claims that's the only thing the causes feedback (... it's the singer's fault).
Posts: 1487 | From: Irvine, CA, USA | Registered: Jun 1999
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posted
in a nutshell, feedback is caused by pa systems hearing themselves, thus causing feedback. if you have feedback you probably have the gain up too high somewhere in the signal path, or you will have to reconsider the placement of your speakers.
------------------ DJ Mad Maxx Karaoke done right!
Posts: 1898 | From: DuBois, PA | Registered: Jun 1997
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posted
I don't know to much about frequencies crossing and all that stuff!!,but, Feedback is all in the levels for the most part.Plain and simple,if you have lows to high,mids or highs to high it's gonna feedback.The EQ is not always a smiley face,if it was then why bother making an EQ!!It depends on your room that your in.Your gains and volume is a factor also,and being to close to the speakers.Fixing the problem is not that hard,if you hear a high piercing feedback that is your highs,if you hear a low feedback obviously thats your lows.I never really heard of mids feeding back because you really dont need so much lows cause all they do is bring the highs and lows together.
I disagree with it being the singers fault,Grateful,your buddy there is one of those people who thinks they know everything but they don't.It's not always the singers fault,you think live concerts dont get feedback?
posted
In a karaoke setting, feedback is almost always the result of a speaker interacting with a microphone. Sometimes this is because the singer wanders too close to a speaker or other times it is because you have the gain too high on the mic because the singer is so SOFT. I have never had to use my EQ to eliminate feedback in this type of environment. I use an EQ to make the mixture of music and vocals sound better in the different enviroments I play in.. (ie carpeted rooms versus hardwood floors, etc). Once it is set for the particular room, I rarely have to adjust it.
The way my speakers are usually situated, there is virtually no chance for the first type of feedback unless the singer decides to go off "working the room" and gets too close to one or the other. The second type of feedback is usually avoided by carefully adjusting the gain on the mic for less powerful singers and not adjusting it too far. Sometimes all it takes for these types is a little encouragement to sing a bit louder and the problem is solved.
Posts: 575 | From: West Hartford, CT USA | Registered: Apr 2000
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Vox - You're right....you don't know much about frequencies, etc., so please stop spreading misinformation. Most of the feedback (at karaoke shows) is caused by midrange frequencies, and mis-handling of the microphone by an inexperienced singer is a very common vehicle for it.
Let me just say this once for all the KJs and audio techs out there.....
Please DON'T wrap your hand around the top of the friggin' mic.....EVER!
It always (yes, ALWAYS) makes your voice sound like CRAP, and it makes you look like an idiot who knows nothing about how to use a microphone.
Here's the scoop, folks.....
Wrapping your hand around or "cupping" the top of the mic is a stupid thing that they do in music videos that doesn't work in real life. It's kinda like turning your gun sideways....it looks cool in the movies, but only idiots and amateurs use it in a live performance.
Yeah....sometimes you'll see "real" singers (mostly rappers) cupping mics at a live concert, and guess what? They sound like sh*t, too, and they're also annoying the hell out of their sound techs the whole time. Why do they do this? For the same reason that some karaoke singers do....because they're clueless. There are a lots of clueless "professional performers" out there....being a commercially successful singer doesn't necessarily mean you know anything about audio.
At one point in audio history (before there were good vocal effects available), cupping the mic was a way of creating your own "pseudo-reverb". However, mics were different pick-up patterns and sensitivities then...and most were omni-directional. Now, when you wrap your hand around a mic...chances are, you are condensing the signal in an improper and unbalanced way through a unidirectional cardiod, hypercardiod, or supercardiod pattern.
Depending on the individual circumstances, this usually generates a higher gain on certain frequencies...and consequently causes feedback. Even when you get lucky and don't get feedback, cupping the mic always causes, at the very least, severe distortion. It doesn't sound cool...it sounds lame, sharp, and annoying.
Bottom line - If you wrap your hand around the top of the mic, you'll sound like crap, and there's very little a KJ can do to make you sound better. It drops out your mids and lows, it screws up the effects (reverb, etc.), makes the tones thin and tinny, and generally makes you sound like you're singing Aqualung with a headcold on an old AM radio. Basically, it sucks....so don't do it.
I'm sorry to throw out such a harsh dissertation on this subject, but it's a sore one, and here's why....because when a singer causes a sound problem, it reflects badly on the job we (KJs) do.
When a singer causes sound problems by mishandling the mic (cupping, whispering, "eating" the mic, or won't get anywhere near it).....people who are listening will always blame the KJ....assuming that they can't run their sound properly.
Inevitably, someone will run up and try to tell the KJ that the singer doesn't sound right, and they never consider for one second that it could be the singer that's the source of the problem, not the host.
As a KJ, it can be very frustrating to take this kind of crap when you know it's not your fault in the first place.
Of course....on the flip-side.....I have little respect for operators who just set their levels and walk away. Track volumes vary, vocal volumes vary, and voices sound different at different projection levels....and it's my opinion that part of your job as a sound tech is to be on that stuff as much as possible.
Yes....we all know that there are about a ka-jillion KJs out there that either have crappy equipment, don't care about their sound, or don't know how to run it, and that sux. And yes, it is also the KJ's responsibility to instruct singers on how to use the mic properly, but you'd be surprised how many singers just decide to ignore it.
Sorry....but if the singer is told by the KJ something is wrong, and does it anyway (which is the case most of the time), then it IS the singers' fault. All I'm saying is think twice before you go automatically beating up the host....'cause there are two sides to every story.
One of the better ways to assist in eliminating a general feedback problem is to upgrade to a higher "gain before feedback" mic....such as a Shure Beta 58. It really helps a lot. - L .
[This message has been edited by Leigh Balton (edited September 05, 2000).]
posted
Hi Leigh, You are one hundred percent correct-a-mundo, DON'T CUP THE MIC!!!!!! unless of course you want to sound like an idiot
Posts: 29 | From: cresthill, Il. U.S.A. | Registered: Sep 2000
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posted
If you misinterpreted what I said about the KJ saying it's the singers fault, then I apologize and should have explained more!!
I wasn't attacking KJ's,I was stating!! It's not a singers fault if there's feedback.
I've been singing all my life and having feedback has not always been my fault!!
Spreading mis-information is something that I haven't done.If your saying that feedback has nothing to do with
levels
at all then I think I'm missing something!!I understand about all the inexperienced singers out there and the cupping of the mic,and being to close to the speakers!!
I took a simple approach to the situation!!that's all!!
What I want to know is how do Mids have most control over feedback?Doesn't it depend on the room?(that's a serious question,don't go getting all snappy at me please because I snap back!!lol!!)
Truths people....take it easy!!
------------------ Vox
[This message has been edited by Vox (edited September 05, 2000).]
posted
I'll have to add that there is a time and a place to cup the mic. Personally, there is one particular song that I sing which requires certain sections of the vocals to sound muffled and distorted. The only way to do this (without an effects processor and a sound man) is to cup the mic. I don't recommend it for 99.9 percent of the songs out there, and I also recommend learning how to cup it properly to gain the effect, but as is so often the case, "there can be no absolute rule".
Posts: 1691 | From: USA | Registered: May 1999
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posted
L'op...I know what you mean..."Mudshovel" by Staind has sections where the vocals ARE distorted and sound like "crap", so to speak...careful "cupping" can acheive this effect, but you HAVE to know how to control your OWN vocal volume (in your throat, that is) in order to pull it off, not just cup that sucker and HOOOWWWLLL!
------------------ The K-Wolf, Daron
Posts: 490 | From: Irving, TX. USA | Registered: May 1999
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posted
There are also parts of "Mexican Radio" where the lead is supposed to sound hollow, and cupping the mic in a certain way works just fine. (works better with Shure Beta 58's than regular SM-58's).
Of course, this is a professional mic technique, we all know just how good at mic technique most karaoke singers are. . . .
posted
My friend does all the Jethro Tull songs with the mic cupped, and he sounds great! (I was going to recommend him to Your Big Break).
But, sometimes some singers will cup the mic when they're not even singing... they're waiting through the instrumental break and don't know what to do with their hands. Now, that's quite annoying when there's feedback going on.
Posts: 1487 | From: Irvine, CA, USA | Registered: Jun 1999
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posted
I don't recommend cupping, ask the K.J. if he does have a processor (any accomplished K.J. does) and ask the K.J. to let the processor do the distortion, or megaphone technique, cupping only makes the sound system sound generic
Posts: 29 | From: cresthill, Il. U.S.A. | Registered: Sep 2000
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posted
But Kix- with my song there are a few parts that require effects, and the rest don't. Local KJ's aren't sound engineers, and they don't know the parts that need the effects. I do.
I reiterate, it is a mic technique, most singers don't know how to use it, some do.
Mid range levels, if not set up right will no doubt give you more chances of feed back by the people "Trying" to look like they know what they are doing, ie: singers cupping the mic,...Over-all sound levels settings, volume, depend completely on these settings being correct as feedback can happen even with the volume very low...cupping the mic screws this all up!
For example, anyone that does cup their mic that you see on a video or in concert, is usually: (a), is NOT really singing, OR (b), they are working with a sound person who knows when they are going to do it... THEN the sound person will usually turn the effects levels down or off...so the singer can sound like crap on his own. LOL.
High Squeal feedback happens mostly at band fq levels of 2000hz, sometimes 2500hz, and frequencies at 5000hz... Low-level frequency feedback, below 250hz, also can be pretty bad to experience if someone decides to get too close to the subs....
Yes, I do see many people who use the cupping method in karaoke and it is stupid.... don't do it! If I remember right, this is a method people use who can't afford a sound processor.
BTW, you can sing fairly close to the speakers IF you have the eq settings right even if the volume levels are high....just don't stick the stupid mic in it LOL..
[This message has been edited by fdcat (edited September 10, 2000).]
Posts: 176 | From: Orangevale, CA USA | Registered: Sep 1999
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posted
Someone metioned it early on, the best bet is to put a feedback eliminator in your system. The new one have very narrow filters and do a good job if you set them up properly.
Posts: 32 | From: St Peters, MO, USA | Registered: Aug 2000
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posted
Kix- to a degree, yes, KJ's are sound engineers, but if I give you Mexican Radio, are you going to sit there and turn on effects at just exactly the right moments? Didn't think so.
Posts: 1691 | From: USA | Registered: May 1999
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posted
Kix: "responisble for the sound" doesn't necessarily mean "knowledgeable about the technology involved with sound"...I for one keep an EQ in one fixed position. I dabble with echo, but until a company puts out a manual "Sound for Dummies"...that's about it. And I better not hear the smug "well, if you can't operate yer equipment you shouldn't KJ" spiel...it's not just technical stuff...I can drive my car, but I can't fix it. The same with my sound. I will NOT endeavor to repair my speakers. I don't know what I'm doing short of plugging and playing. I leave the tech work to the techies, and do what my job entails: ENTERTAIMENT THROUGH A GROUP INVOLVEMENT EXPERIENCE. (it was either that, or pump gas...KJing doesn't make your hands stink so badly)
------------------ The only thing better than karaoke is BAD karaoke!
Posts: 745 | From: Portland, OR, USA | Registered: Aug 2000
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posted
I use a 31 band (1/3 octave) eq. It's between the output of my mixer and my powered speakers. I have found that, in my particular case, by notching out (reducing by 3-6db) freq's at and around 400Hz, I eliminate virtually all feedback. And it doesn't affect the rest of the sound enough to make a difference to even the most trained ear. Trust me, no one has ever walked up to me and said, "man, your rig sounds like crap! Do you have 400Hz notched out or something?" My system: Mackie 1402VLZ Pro mixer, Rane Mojo ME302S eq, 3 Alesis NanoCompressors, Alesis MidiVerb, SM58 wired and wireless mics, EON Powered 15's. It all requires fine tuning, but once there, the quality of sound pays off. I play loud and hard when the need arises, and coach the singers as needed, and have virtually no feedback problems. Although feedback eliminators do work, they are expensive and finicky. Stay away from them. By the way, if ppl at my shows cup the mic or otherwise use what I consider bad mic technique, I'll quickly and politely try to coach them how to use the mic. After that, I'll adjust the gain as best I can to accomodate them and then after that, let them flounder. Hey ppl. Isn't Karaoke supposed to be FUN??? Sheesh.
Posts: 123 | From: Ocean County, NJ, USA | Registered: Jun 2000
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