Sound Advice - tips for fighting feedback in your live sound rig
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- เผยแพร่เมื่อ 29 ก.ย. 2024
- a quick and easy visualization of what feedback is and how to get rid of it from your PA system. This is not an all-inclusive tutorial, but it will help you understand the basics of what to look for and how to troubleshoot your rig and improve your sound!
Your info is very good. Too bad so many people complain instead of appreciate what your offering. I for one appreciate you posting this.
Cheers
Not cool with the levels bro... I had headphones in. This could have seriously fucked my ears man.
Great informative video! Thank you
Great
@chrisgee15 whats HF?
Next time, please raise the volume of your voice. I turned up the volume to hear you better, then BAM feedback effect.
Tanner Hoke That's *exactly* what I just did.
along with everyone else. I think he's just a live sound engineer and not an audio engineer.
You sound like an audience member after feedback.
Or not play yet feedback
I stopped watching as soon as the second LOUD AS FUCK feedback 'example' blew out my headphones.
are the speakers movable?
I think one main thing he missed, is very important in basic PA setup, is speaker placement. and I see people mess this up all the time.
there should be a shear line, where the speakers fire away into the crowd, and the microphone should never be in front of them. People want to stick the speakers at the back of the stage for aesthetics, but they wind up firing direct into the mic. make sure your mic doesn't pass the invisible line directly between the speakers.
Wireless mics give you fits. A performer does a hair flip and the wireless mic is 2" from the monitor followed by a high pitched feedback squeal. A performer runs around the stage with a wireless then goes out into the audience in front of the FOH speakers and you get squeal. The sound person gets the blame but in truth it was caused by the performer. You set a gate in the mic and the performer gets mad because they can't scream into the PA. The performer decided to whisper and nothing comes out because the noise gate is closed. Lol. You can teach all you want but the real learning comes with experience.
@Jonas Anderson You did fine with your computer mic. You just didn't have to play the feedback sample so loud to make a point.
you lost me right out of the gate with the feedback! A warning would have been smart. The level was so low I had turned it up in my ear buds..........ouch!!
There is no mention, but I think a short delay will works also. By using the short delay is synonymous with extending the distance between the microphone and the monitor speaker.
You really should never do that
Thanks for this video. But can you make one video in the actual of removing feedback? please... thanks in advance.
Don't gate vocals!!! It can get really nasty.
in live it is a trapbecause you can`t manage the stage level,it`s not the miracle solution against feedback, if you have enough freechannels, use one for the foh with a compressor the other one on another channel wiz
th a y cable to use a different eq.
REST IN FUCKKKKKING PEACE HEADPHONE USERS. WHAT THE FUCK?!!!??!?!?!!??!!?. Very helpful video though other wise
thanks it helped understand alot but my problrm is not while speaking its as soon as i turn the pa system on or the channels for my condenser mics, we used it before not a problem now bigger room and diffrent cables and as soon as i turn it on its an instant loud mid tone the gain has to be turned way low but then i run into very little pick up any sugestions..
You sound so young like you could be 17 and you have the best video on the topic lol thanks a lot !
Thanks dude. I'm using nylon string guitar,harmonizer,zoom A3 w feedback suppressor. I was aimims speakers at mic. This and the room created mega problems at practice. Now I know what to do..... THANX
Very nice presentation. I've never really had feedback issues. I mute unused mics and cut the lows on the vocals. I love the panic as someone drops ALL the faders on the desk when they hear feedback though.
lol your mic level itself is distorting and making it pop...and your trying to teach people about feedback when you cant even get your mic levels right? lmao
Thanks, good tutorial. Last week I experimented with my Bose S1 Pro which I use with a Shure SM58. I found that IF I TURNED THE BASS WAY UP, THE FEEDBACK GOT SIGNIFICANTLY WORSE. Most people on stage only have access to Treble, Mid and Bass; (the S1 Pro only has bass and treble) so I guess they have to fiddle around and find out which frequencies are making feedback worse.
1. Your voice volume is way too low... 2. You do NOT need to insert loud annoying feedback noises into your video...everyone knows what feedback is or they wouldn't be watching this video to begin with. 3. Otherwise good explanation and advice.
FYI: most analog 1/3 octave EQs have octave-wide filters centered every 1/3 octave. So, you're not cutting or boosting only 4 notes, you're cutting/boosting up to 12 notes. If you cut a graphic at 1k, it will affect down to 500 Hz and up to 2k. Some digital EQs allow you to set how wide the filter is, but most start with a default of an octave wide. Depends on the hardware/software.
1. Pre-amp gain does not change the "size" of the polar pattern. This is a common mis- representation.
2. GEQ is for tone shaping. PEQ is for "surgical" adjustments.
3. FBX units are not a cure-all and when you understand how they work you won't need them.
4. Never, NEVER use compression in monitors.
The best way to decrease the chance of feedback is to use learn how to position, aim and process your PA speaker system. Anything else will be in the realm of surgical dressing for what should have been preventable wounds.
Turning up the gain affects the polar pattern! This is not an accurate visualization. Turning up the gain amplifies the signal entering the channel. Everything before the gain knob performs exactly the same before touching the gain or trim knob.
Use a behringer ultra feedback destroyer.... it’s quite good
compression does not make anything louder. compressors squish/compress the opposing sound. another words it allows one sound to duck under another to allow those frequencies to be more present in the mix. example... when the kick drum hits, you want your bass to kind of quiet down to give the kick more presence. The kick does not become louder, It is still at the same Db.
the video was done with the built in mic on my computer. those mics are typically not known for high fidelity :) I hope it didn't take too much away from the content of the information.
thumbs down only for the annoying loud feedback sound about 20 seconds in, and then you played it again at 53 seconds, I'm out.
"Feedback, It's very unpleasant" - Yes, it is! Thank you for demonstrating that! My neighbours really appreciate it. You could present the example at lower volume; a warning, perhaps!? I'm surprised you weren't more judicious considering the work you put in. A good video all the same
Found out what it was. It was the pc mic on my laptop. Don’t know why it turned on by it’s self. Smh.
Well, you need to turn up your mic on this video. Can't hear you.
Great presentation: very informative, concise, and yet pretty thorough! Thank you for taking the time to prepare this video. I didn't realize that the cardiod field expanded/condensed in direct proportion to the gain. Also, the tips to fighting feedback were insightful. I can't wait to implement the info at our church. Thanks a lot, Jonas!
Your guna give people hearing damage if you don’t turn up your fuckin voice my guy, holy hell.
sounds like i can avoid feedback by not watching your video thanks
I thank you very much it is so help full .not only for me but also for all our staffs .
Daniel from Ethiopian national theater.
thank you, my church will definitely benefit from the gained knowledge.
Fantastic explanation, Jonas. Your tutorial was obviously intended for those of us who don't call ourselves "sound engineers". It is very helpful to me. Thank you!
My philosophy is the same as yours... I shoot for 0 db on the LED's and go from there. It is OK for the meters to jump past that - in the sense that if it spikes once or twice, it's unlikely to cause any permanent damage to your gear. I still try to avoid it, better safe than sorry. Live sound is an unpredictable field, it helps to know the rules and then be ready to break them if the situation calls for it (especially with human vocalists... the most unpredictable!). Hope this helps!
Jonas you're very good at replying to comments , I used to habe a friend called Jonas , he was a nice guy. Also my cousins surname is Anderson, my uncle tels me it is of Swedish origin. So ye, love your name too, was Jonas I'm the bible or something, lol, don't get me started on that, I've been listening to the audio book version, did like 3 books, got bored. 😅
Lesson learned: it's all the vocalist' fault
Good, vid. A simple math method to spot the most likely feedback freqs: divide the speed of sound by the distance between the mic and the nearest monitor. Most often, in a open space, it's around 1.8khz.
1.8 kHz would indicate a very short distance according to your formula, about 0.6 feet (speed of sound is 1100 feet per second, divided by 0.6 feet gives 1800 Hz). I'm just trying to understand how the formula works. A monitor that is 10 feet away would resonate at 110 Hz (1100/10 = 110)? But in an open space, the distance is somehow shorter (less than one foot)? I wasn't able to find this formula elsewhere. Thanks.
Lol, can this guy make all the videos about live sound on TH-cam please, like give him a monopoly on it, he deserves it for this superb video, I learned a great deal and I've been gigging in tight spaces all my life, always battled with feedback even now after like 15 years of doing it. The video taught me a lot and I'm going to try theses things at my next gig. Because tonight I had this massive runaway rumble during one of the songs , I'm not sure weather is was the microphone or the guitar but it was so bad a actually had to stop the song and turn the mixer down, luckily it was towards the end of the song and I pretty much got away with it with a sympathetic o you fu×ed it up clap, lol.
O ye, I forgot to say, I was standing right at the back of the room as well with my back against the wall, that didn't occur to me something I learnedin your video, because I'm an idiot, who can't be arsed practicing with his full pa at home, but i should realy, but you cant make nosie as my house, so have to learn on the job, which in this instance isn't a very good place to learn because you're under pressure 😀
I am so happy that you cleared up my confusion about: unpleasant or pleasant. ;)
I really like this video, thank you so much for the help! I do wish the feedback sound effect was turned down by half though!!
that's exactly what my vocalist looks like. lol
It’s not the mic doing it for me. Trying to find out why I’m getting feed back. The mike doesn’t give me feed back. I wonder if the speakers is to close together. I’m getting it when my PC goes into the mixer only. And only at high volumes
Ha ha haaa! Such a great feedback tutorial!
ouch.....my ears are broken
No matter what feedback destroyer you use, if the acoustics of your room is bad, the sound is gonna be bad. If you don't covers the walls and ceiling of your auditorium with foam or glass wool, it's gonna be crap.
ThalesPo foam was a very bad idea at The Station (big huge fire in 2003, killed 100 people) and I can't imagine the average person spending the $$ to buy the expensive stuff that's fire *resistant.* Fire proof, is of course, another, VERY expensive animal.
Could just turn down a bit, back up from the monitors/mains, use in ear monitors, back off on the reverb, use a better mic that's not as finicky...the cheaper the more prone to feedback. I've seen total garbage Radio Shack crap with rules about "you can't walk around with the mic." Which is stupid. Just buy a Shure 58 or better...I like the 58s, never have bad issues with them, and I play drums and sing in my house. Big, acoustic drums. 9 foot ceilings probably help out with that, but the rooms aren't that big. Things I've heard used to dampen sound that are as safe as you'll get: record or book collections. Natural fiber rugs, such as wool. Wool doesn't burn easily should something bad happen. And I've had stuff short out, and heard about fires under stages during shows run by professionals. It's an unbelievable smell; if you know an audio dork, ask them for a speaker that got that funky burnt smell. You'll never forget it, and you'll know you have a serious problem on your hands. But look out near the drummer, they always have fans, and when they're on, you couldn't smell ANYTHING burning...
I’m deaf now thanks
Hi can feedback destroy a microphone?
Nope. It's not pleasant, but it's more dangerous to your ears than the microphone. It also takes a MASSIVE amount of feedback volume to be dangerous to your speakers or microphones. Feedback is more annoying than destructive, but hopefully the tips in this tutorial will help you to keep it at a minimum.
Mate, if I'm looking for a video about how to correct feedback, I probably know what it is, good video though, thanks for your efforts!
I'm sorry about my first sarcastic comment, your video is actually very informative, and you clearly have a good insight into how live sound works. 👍
This is the best video I've seen for ages. Wel done man, you did a belter of a video.
Thanks a lot for sharing the invaluable information.
Good!! Thank's, this is a nice tutorial with pro knowledge.
When I set a vocalist's mic should I try to shoot for 0db on the LED Meter on the mixer ? I have an issue with another sound man he say that I do not use enough gain he says that it is ok for the meters to jump up above 0db or unity is this true ?
This was really helpful :)
Some sound guys try to really max the gain level right at the edge of clipping , You can get away with this depending on you gear's over all capacity however I alway give myself a little gap just before clipping by allowing the meter to ride slightly into the yellow zone. If I hear any distortion in the speakers then I will back down on the gain. and try going up at the fader instead 0db is the safest though.
This is what I deal with all the time in church. I handle all sound and play the piano as well (no one to do it plus I'm inexperienced) so I have the singers constantly telling me to turn this person's mic up or someone else's mic up and there is a whole lot of feedback going on. I would love to improve so I won't have to deal with that problem anymore
That's the whole reason I did this. I worked at a music store and was constantly heading from churches about feedback issues. Good luck! I hope this video helped.
In my opinion it's not a matter of turning up everything all the time. You get a sort of battle of volumes then... you can also think of leaving some information out on certain monitor channels, like instruments a singer doesn't need to sing properly.
Or just start all over at lower overall volume.
When you have multiple singers you could also try shift the phase of some mics. Most panels do have a button for this next to the gain.
@Ryanincambonia
1) make sure you are not "cupping" the mic- this will almost always cause feedback
2) make sure your mic trim is not too hot....put your channel into "solo" and shout "HEY!" ..the mixers meters will show your level- if it is going into the red or close, turn the trim for your mic DOWN.
3) your speaker/amp combo may just be too modest. get a more powerful system. And tell your band to turn down!
4) if none of this helps, get in-ear monitors :)
It wasn't mentioned, but you forgot the problem with using crappy gear. I don't get feedback much, but the OLD JBL monitors are WAY less tinny, so less feedback, warmer sound. You can get all the bass and drums in without needing subs most of the time.
Reverb units can be problematic without a compressor first. I've also NEVER been able to get a headset to work right at my house, and neither could my Columbia professor. It was Sennheiser, too.
Could also turn down from the trim at the top, NOT from the fader, because the signal runs top down.
there are a couple of in-line things called "feedback eliminators" made by Behringer or Sabine. I would recommend trying one and see if it works for your situation. I haven't used any feedback busting software yet. In a single mic situation, spend a little time with a feedback eliminator. Also, don't discount mic placement (closer to the mouth or throat) and speaker placement (try to point them away or at an angle). You might also want to check out the mic pattern. I have a mic vid that may help
I agree. It's the least effective thing a person can do... like turning the car off after accidentally grinding the gears. Muting the unused mics is a great way to reduce the overall noise floor, and most vocalists don't have voices that go down to 80-100hz, so dropping the lows is another great way to manage your live mics. thanks for watching!
Great video! Can you explain how each slider is 4 notes on a piano? An 88 key piano starts at roughly 26 Hz and goes up to 4.2 KHz. So to EQ a piano with a 31 band EQ would you only use 25 Hz up to 4KHz? This would give you 23 (or 22) bands you could use for the piano. 88 divide by 22 = 4. Thank you!
LOL!!! There are no bad notes! There's a simpler explanation. In open air you need little eq if any at all. This is because all frequencies generally react the same in the open air outdoors. Indoors, sound will bounce around the room, some will get absorbed, some will actually get amplified by characteristics of the room, making those frequencies react more violently in kinetic energy than other frequencies. Yes loops occur, but there's room ring, room ring return (looping from the room ring), return ring (loop), and presence. 4 kinds of feedback, and the first 2 are the ones pros usually fight, while the last two are usually handled by placing speakers and mics correctly, and are also handled by taking care of the first 2. Why? Simple... ...If you eq for the room as it is set with speakers mics and all, you can get it done all at once, except for presence. Presence is also related to "Color" of the sound of the mic, and can be adjusted at the board's 3 or 4 band parametric EQ (hi mid and low adjusters). First, clear the room. Some run pink for really dead rooms or difficult rooms. I do occasionally to speed it along, but you don't need it every time. Place a 31band graphic eq on the output busses going to speakers. This will be important later. Keep a keyboard with a mono headphone nearby, preferrably one in which you have taped the frequencies of notes onto it so you can compare. If your eq has a feedback detection system, forget the keyboard for now. Set the master or output faders you are working with to zero. Get each mic channel checked to about -6 for vocals or -12 for instruments at unity fader. Now push the mic faders all the way up, and slowly increase the master or output section, when you hear a ring, pull back until it goes away, then push up slightly, and use the keyboard or feedback detection to find the frequency, then drop that by 6 (most say 3 but this method requires more kick drop 6 if you've got it), and continue boosting the master or output until a bunch of frequencies react at once. You are now at a relative zero point accross the board, or the point at which the sound reacts as it would outside in open air. Now check the mics at unity faders, yell at them etc to get ring, and take it out by 3 to start then 6 and so on. Now you should be able to talk into them and adjust your color subtractively---This means you decide what you want more of, and drop everything else by 3 using the 3 band parametric eq on the board. The last check and yell takes care of loop ring and some presence ring, but the coloring of the mic makes it more real sounding, and lets you gear it for the sound source. IF you decide you want more mid and try to raise it, you've just reversed your backend eq. Drop the Lows and the Highs and you'll be working WITH the EQ, pushing down the trouble areas more for the areas you drop for that mic, but the effect is not completely cumulative. It's logarithmic. For two mics the effect doubles, then again at four mics, then again at 8, and again at 16, so more mics affect it less and less, and color becomes less adjusting at the back end eq, but adds more flair to your sound. This whole process takes about 20 minutes, and has worked for almost every live venue I've done without pink noise generation. One or two were really dead or I had a bad cold or something and my ears weren't great at the time, so I relied on pink to help force a faster and louder overreaction.
Just as important, if not more so to reducing feedback is mic technique. Keeping the mic very close to the source allows you to keep the input gain down which will reduce the chance of getting feedback. I had a retirement home client that was experiencing feedback in their dining hall. It didn't help that the speakers were in the ceiling. I trained the staff to hold the cardioid mic level with the ground and almost touching their mouth. I turned the gain down on the mixer and the problem disappeared.
MY NAME IS JONAS
I'm going to use parts of this to show my vocal students how to.use microphones properly. And save themselves from a bad mix due to guys being paid in beer...
@Ryanincambonia: where and when is the feedback happening? email me direct, and i will try to solve this with you.... also, define "loud enough". it might be situational. let me know, i'll do what i can. thanks!
Thank you so much! Excellent video! Now I have a better understanding of how to go about fighting feedback.
Excellent video man, very informative.
Just as a side note, compressors don't make quiet sounds loud, they only do that in the sense that you are using makeup gain. And after you have set the levels of the compressor, I don't think you would ring out a room with your band still playing.
Compressors can be troublesome with feedback, but more than likely would be when you have to go back to it and adjust the settings after you have rung out the room.
Still though, great video.
How to identify which frequencies are causing the feedback?
You already mentioned it's not an all-inclusive tutorial, but I think people who are watching this can be helped a lot with a practical approach. So I have decided to give this a try - at least in the way I should do it. Please comment!
In the right order:
1. When you set up the sound system in a new room with unknown acoustics, first "beep out" the feedback frequencies. Put a reference microphone on a stand on the stage, and crank it up carefully over the PA until you can hear some feedback. Search the frequency and suppress it. Now push it further and you will probably notice another frequency will give you feedback. Repeat until you're done. (B.tw. the reference mic is not some fancy microphone, just use one you need for vocals and put it on the spot they're going to use it)
2. Do the same with EQ-ing your monitors.
3. Let (for example) a vocalist sing and try to figure out at what main frequency his or her voice acts. When you have a parametric EQ: boost the mid heavily and go sweeping until you hear where the most amplification is. Compare the voice with and without amplifying it to give it a natural sound. You might turn the gain a bit down now - don't exegerate.
Now, take the rest out. It will prevent "bleeding" and thus feedback. Bleeding happens when a microphone picks up sound from other sources which are in the direct vicinity. You can not prevent it, but you can reduce it - also by good placing of the mics to other sources and eventually shifting the phase.
Be careful though not to take too much out, because you will end up listening to a singer singing in a tin can....
Of course you can do this with everything you mic, not just vocals.
That's about it for now :). Have a good gig!
thanks a lot.... I've actually got a couple cued up and haven't gotten around to narrating and uploading them yet. I'm out of school for the summer, and they're now on my "to-do" list. Thanks again!
jonas
Great video.
Hey Mahcsm, in my experience, once you find the feedback, using a sweepable EQ from your board (if it has one) or an outboard EQ is the most effective way of getting rid of it. The XTI's are wonderful amps, but real-time feedback isn't really one of their strong points. I hope this helps! Jonas
Wish you would of covered board channel eq. Pre and post eq. How board channel eq affects the monitors with most analog mixing boards and digital you can change pre and post via built in adjustments. However all n all good.
Wow, thanks! I thought he was poorly cast as Spiderman, but I appreciate the compliment! I'm glad you benefitted from the video. Good luck and God bless!
That's great info! Most hardware EQ's have a fairly wide Q (width), and they do effect more than just the fundamental 4 notes... sometimes dramatically so. Thanks!
Jonas
Lo
I love my gates and compressors- especially with mics on instruments.
This video (was uploaded 10 years ago) has the best way to explain about feedback problems. I love the funny pictures and the hilarious way to teach the amateur like me! Thanks Jonas!
A tutorial on sound with poorly recorded sound. Pass.
Wow! There was more info packed into this vid than any other vid about this stuff that I have watched in the last 6 months! It was so clear that I didn't need to rewind to "get it."
Thank you, thank you, thank you! :)
Thanks for taking the time to explain through your presentation. I found it extremely helpful. :)
Dude, great vid, even 9 years later. Apprently having good content, good sound quality and some jokes sparkled throughout goes a long way
Hey Jonas its Chris Morita hows it going? Great vids you posted take care.
very dangerous.......
easy fighting feedback with Behringer feedback destroy
I thought the piano was a full range instrument. full spectrum in the eq
Excellent really useful. Cheers from Bonnie Scotland.
ive tryed all these things and i still cant get my volume loud enough without feedback, someone help mee!
Thank you very much! This video was extremely helpful! I am a mobile dj for small bars, so naturally my speakers are close to my booth. I have been getting unwanted feedback from the mic and speakers and I didn't know what to do. This cleared up everything for me. I'm glad i don't have to go out and buy new mics or speakers now, or some gigantic mix board, just to fight feedback. THANK YOU THANK THANK YOU 1000 THANK YOUS!
Nicely done! Your explanation was simple yet effective, especially for a neophyte like me. Thanks. BTW - I thought it was Tobey Maguire speaking.
SUPERB presentation - All meat, no fat - a GREAT roundup of core concepts!
(Bonus points for being so young and delivering such polish - that was a corporate board-room quality presentation)
Thanks!
I looked and didn't see anymore vids from you like this one. I'm shocked! You are a fantastic instructor! You should really make more, more, more! Please:)
I loved the video, but what is it that you did exactly to help you with the feedback. I am in the same boat... I do everything I can with Speaker Placement and I love my setup,, would hate to add unnecessary equipment. Did you get an EQ, Feedback Suppressor?? My CrownXTIs have DSP/EQ, but hard to use in real time to eliminate feedback...
Thx
great video.
The sad thing is that as soon as you stick eq on any speaker it creates all sorts of issues with the sound and will ruin almost everything that goes through it. Although most speaker manufactures do it as it is easier to make speakers that way, definitely not better though.
Hey Jonas. Great video man! I loved how simple and informative you made it. Thanks for sharing your knowledge hear dude. :)
Dude you helped me sooo much. Me and my band can practice a little more peacefully now. Thanks
The video is a great packed lesson against feedback. Apart from the definition of feedback (I find it a bit simplistic and questionable)
For me it is interesting your video because I work WITH feedback.