I am researching ways to minimise microphone feedback in a live situation with a rock band using a PA, backline and wedge monitors.

I was watching a very helpful and insightful video about this subject. One of the things it mentioned was that increasing mic gain (not volume) on a mixer actually increases feedback and background noise going into the mic. The guy in the video says to prevent this you should set the mic input gain low, just loud enough so you're hardly picking up any background noise through the mic, and then to increase the level through the PA you should turn up the volume (not gain) of the mixer channel and your powered speakers.

This sounds very logical, however I was always led to believe that when setting the input levels of mics and instruments on a mixer (for both live sound and recording), you should set the level just about the point or slightly below where the clip indicator light comes on. That way you'll know you're getting the maximum possible input signal without clipping. However what this guy said in the video contradicts this, so I'd like some clarification on this subject.

Here is the video btw. The bit about setting input gains comes in around 6m04:

https://www.youtube.com/watch?v=GISdJKWhEls

Gain is gain so it doesn't matter where you get it, in any given situation there is only so much total gain a system will tolerate before feedback becomes a problem.

In my experience doing live events that doesn't work well at all, the mic gain should be hot but never get anywhere near clipping.. there needs to be some clean headroom available or the mic becomes feedback prone. The reason for this is that clipping is effectively a form of compression which also raises the gain but in an uncontrolled way and you can't do that when the system is already at the threshold of feedback.

This vid popped up on my YouTube feed after I watched a few others on the same channel. I've found this guy's videos in general to be very good. I hope this helps.

https://www.youtube.com/watch?v=nsulprafYWU

NEWSFLASH don't ever take sound advice from a DJ. I didn't watch the video and what he is saying could be right. You want to minimize feedback don't use a zoom livetrack that doesn't have graphic/parametric EQs available on the outputs.

The Zoom L-20 has a 15 band graphic EQ on the master outputs, which is controllable by iPad.

In this day and age where you can have parametric EQ on all inputs, master out and monitor sends, a 15 band is laughable - it's not even a 30 band so you're just notching out giant chunks of the frequency range.

For live shows, there are a lot better choices in digital mixers to fight feedback and have better control.

You can adjust the Q setting of each frequency, so that will allow you to zone in on more specific frequencies.

I'm not sure why you think you need graphic EQ on every input and output. Sometimes keeping it simpler with EQ settings is easier and better than spending hours trying to be too perfect and precise with 30 band EQ.

Such as what? What is better than the Zoom L-20 in the same price range? Sure, you can buy a Behringer X32 compact, but they're twice the price of the L-20.

The only mixer I can think of that is similar in the L-20's price range is the Presonus StudioLive 16.0.2 USB. Can this do separate graphic EQ on every input and every output?

One advantage to the Zoom L-20 is that you can record on it, rather than having to hook up a computer and DAW, so it's a lot easier to record a rehearsal or live show and then transfer the audio to your DAW later. Also the L-20 has 6 built in headphone amps, so you can rehearse and record with a full band through headphones. No mixer in this price range or even much more expensive ones such as the X32 can do either of these things - you'd have to buy extra headphone amps, thus adding to the cost and hassle. I think the L-20 is good value for money.

You and Modusman's reply smack of the typical 'mixer snobbery' on this site again!

So if your vocals sound great in your FOH speakers and your monitors are feeding back if you try and fix it with your channel EQ you will change your FOH settings as well. Epic fail. My snobbery comes from the fact that I have been doing this for 40 years and sort have it figured out. You on the other hand not so much.

Not if your wedge monitor has onboard EQ controls. You can tweak the EQ from those. Or you can add a graphic EQ unit between the monitor out on the desk and the monitor. You can also use a feedback destroyer to control feedback too. Or just turn your wedge monitor down.

I'm not a gear snob. I started off like you with what I could afford. I've been doing this for many years, and from your posts it's clear you're young, inexperienced, or both. Be humble and learn from others.

Is the L-20 a good mixer for rehearsals? Sure. Does that make it a good live mixer? No.

You don't even know what's out there. A Midas XR-18 costs less and has far more functionality and can also record via USB. Same with the Behringer XR-18. You're talking about monitors anyway, so why not practice with monitors to learn to dial them in vs. headphones? If you really need headphones, plenty of headphone amps from Ross and others that are inexpensive and still would be less than your Zoom mixer.

Don't confuse advice from people who have bought their way up used and know what works and what doesn't in live music as gear snobbery - it isn't. When you proudly proclaim your mixer has a 15 band graphic EQ on the master, it shows that you have learning to do.

I also understand the need to defend your purchase - it's a $1000 mixer and it's tough to hear that it may not be the right one for live music based on needing more control. Take the advice for what it's worth - free, and if you're humble, you may learn something.

IIRC you are in a 4 piece band. So if everyone had a monitor and you decided you need Graphic EQs You could easily spend about $600.00 buying 2 stereo EQs and a rack mount case for them. Not to mention the cabling you would need. Suddenly your $1000.00 dollar mixer costs you $1600.00 to make it usable. Buy one of these instead. https://www.sweetwater.com/store/det...-digital-mixer I owned one for years until I sold it to my bandleader. Never had a problem with it. We will be using it Thursday night this week.

Thanks for the suggestion. Could you also tell me whether the Presonus StudioLive 16.0.2 USB has separate graphic or parametric EQ on every channel and every output (master and aux outs)? One option I'm considering instead of the Zoom L-20 is the Presonus. The fact that it doesn't have headphone amps built in isn't an issue as I could just keep my L-12 for headphone rehearsals, and use the Presonus for live work and full volume rehearsals.

The studiolive has 3 band semi parametric on the input channels and a stereo 31 band for the main outputs. No EQ on the monitor sends.

Get super hyper cardiod mics. The mic pattern helps a lot in feedback mitigation. Mic placement. Speaker placement. Compression. Cranking the preamp. Poor EQ.

A good mic that has a tight pattern is best.

Feedback is when the sound from the source goes through the PA and back into the mic ad infinitum. Sometimes it’s a specific frequency. Most of the time it’s a bad room with tons of reflections or poor speaker placement. Of course, cranking the mic preamp, using compression and adding high end EQ does it, too. But for exactly the same reason.

Mostly, you need to turn it all down or find the freq, mic, speaker that is causing it.

So there should be no compression on any of the vocal mics for live use? I think I had a bit of compression on them via the mixing desk, so perhaps that was contributing to the problem?

there IS a benefit in using lower gain settings (which need to get compensated further down the signal path though) to prevent feedback...

however, mic selection, impedance matching, proper positioning of mics and wedges, using enough but not too many mics in critical positions, using expanders to bring down background noise/spill, adjusting the wedges' response, splitting signals for monitor and pa feed etc. are equally critical if not more important.

Getting deja vu here DD...

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I wouldn’t. I would use only limiters. One on the main for an outright catastrophe. And on the vocalists who require more gain. That way if feedback kicks in the limiter stops it fast.

One knob compressors usually crank the gain. That gain is sucking in all the sound on the stage, which can be what is coming through the mains, creating a feedback loop.

It’s all about the mic pattern, speaker placement, EQ’ing for the room, a lot of room reflections.

I did sound for years in small rooms around Brooklyn. I had a residency at a place in Bushwick. Small room. 24 x 50. I remember someone filled in for me one week. The booker complained about all the feedback. When I checked the system, the fill-in had cranked all the one knob compressors and boosted the lead vocal high EQ.

The best thing I did for that space was buy super hyper cardiod mics, new speakers with tighter dispersion, so that I could aim them better away from the stage and put up some wall and ceiling artwork with noise absorption behind it.

I remember the day I walked into Brownies in the East Village and thought “WTF is this crap?” When the band started playing I completely understood. I never grasped this as a teen at CBGBs. When you walk into some clubs and it’s like walking into a carpeted van. Brownies and CBGBs (Mercury Lounge, too) were great rooms.

My point is that it’s not gonna be just one thing. It’s a basket of things.

Four IMPORTANT things are mics, mic placement and speaker placement and room.

Other things: avoid compression, put a limiter, let the mic breathe but have the speaker destroying ear destroying screeches and pops LIMITED. Avoid EQ’ing like crazy, Buy better speakers for better sound. More bass? Get a suitable speaker with MORE power than the room needs. Don’t CRANK the low on the board.

Turn it down. Get a good balance of a mix using levels rather than some elaborate 8-dimensional EQ scheme. Let the performers, mics, speakers and room work as one. Bring your mains up to a good level. If you need more sub turn your sub up, not the low eq.

Eventually you will find a sweet spot for the space.

They call this “the soundcheck”,

well, level isn't just 'voltage on the fader' (as we used to say in the analog days): it still matters how you get there (even in the digital age) and laws of physics haven't changed lately so i'm not quite getting your point - fact is that most professionals will insist on using different gain settings for foh, monitors and broadcasting but feel free to stick to another approach/technique.

What are some good examples of super hyper cardiod mics that could be used for lead and backing vocals in a rock band? Why are they better than cardiod or hyper cardiod mics?

https://service.shure.com/s/article/...language=en_US
the BETA87A (supercardioid), and the VP89 (hypercardioid).

https://www.shure.com/en-US/performa...nd-subcardioid


https://microphonegeeks.com/differen...olar-patterns/

Audix made the OM7 once.

Every company has a super / hypercardioid line.

From Shure:

A hypercardioid mic is like a supercardioid on steroids; the front pickup angle is even narrower and focused, which results in greater rejection of unwanted noise and feedback. To give you an idea, the typical pickup angle on a supercardioid mic is around 115 degrees, whereas a hypercardioid can be as low as 105 degrees.

This increased focus is especially beneficial when operating in very loud stage environments where unwanted sound bleeding back into the mic can be a real headache. Controlling bleed is imperative on a loud stage; because, if left unchecked, it can result in a washy, unfocused sound - or even worse, feedback. When used correctly, a hypercardioid mic is your best defence against troublesome stage noise thanks to superior off-axis rejection.

There are, however, a few points to be aware of:

1) Because hypercardioid mics are so directional, they require very precise mic technique - even more so than supercardioid. If a singer moves off-axis, the performance of the mic will change, and this can adversely affect the sound quality. In other words, your singer had better keep that mic pointed at their mouth!

2) As is the case with supercardioid mics, a tighter directional response on the front of the mic has an impact on the microphones sensitivity to sound arriving from behind. While a cardioid polar pattern is least sensitive at the rear (180 degrees off-axis), a supercardioid mic is least sensitive at 125 degrees and the hypercardioid at 110 degrees; you will need to take this into consideration when placing stage wedges.

Also, the amount of sensitivity from the rear of a hypercardioid mic is greater than that of a supercardioid - meaning you need to take extra care of any sound coming from directly in front of the singer or sound-source.

3) On many hypercardioid mics, there's a concern about there being too much proximity effect. While this is the case for many microphones on the market, Shure's KSM9 cartridge uses a dual diaphragm element, which helps keep the proximity effect under control.

Try to understand that not everyone has the budget to spend thousands on a mixer that can do everything. Everyone has to work within their budget and then perhaps upgrade in the future when they've worked their way up and got a bit more cash. That's what you and various other users on this site fail to understand.

I'm not such a fan of tablet only controlled mixers. I'd prefer something with real, physical faders. It would be ok if it was a hybrid of physical faders and tablet control, but tablet only is asking for trouble and potentially more technical problems. Plus there's the added cost buying a decent size tablet to have the faders and other mixer controls etc on.

I'd like to get a Behringer X32 compact if I can stretch to it, or find one used. But even this doesn't have headphone amps built in, nor the ability to record onto SD card like the Zoom L-20.

I don't think the L-20 is a bad mixer at all. Sure, it doesn't have as many features as the ones you mixer snobs use haha, but it can do most of what is required for mixing a live band for the budget it's in.

Another possible mixer for me could be the Tascam Model 24.

People have done great live sound with Mackies and a few TC M-One and some DBX limiters for decades. Limiters will save your ears and equipment. Maybe try some noisegates, as well. These are pretty cheap. You can oftentimes find a quad Drawmer unit online for a couple of hundred bucks. Slap it on your vocal mics. With a super hyper mic pattern it should tighten things up quite a bit.

Mackie used to make a rack mixer — I think it was called LM3204 or something.

I think A&H and Soundcraft offer mixers with 4-band EQs low and high shelf with swept mids.

Thanks for the suggestions. You know, I was thinking that I could go for an analogue mixing desk and get more value for money. I mean, is a digital mixer REALLY necessary? You can get 16 to 24 channel analogue mixers a lot cheaper than digital mixers. But then again, they won't have independent graphic EQ for the master and monitor mixes I suppose. They probably won't be able to do independent/customised monitor mixes either. I've seen some analogue mixers with USB outputs so you can record multitracks into a DAW too.

You like a graphic EQ on the 2-bus? Not looking for an argument. Are you using to find feedback freqs or to define a sound? For the monitors? Man, you are too nice to the performers with all these special mixes. I would always just use the simple EQ on the monitor — if they asked. Which was maybe one time. Most people just ask for “more guitar” “more vocals” etc With 4-6 Aux that’s a lot of monitors on a typical club / bar stage.

Depends on how many Aux’s you have. If you have 6 AUX or something you can send something different to almost everyone. Many of these analogue mixers have a usb port for a usb pen drive or to a laptop to record. Or grab a small recorder and hit it with the RCA outputs almost all of these analog mixers have.

It’s really hard to gauge how complex a setup you have and what you need.

I had 4 monitors onstage and a three way stack on each side with two flying 2-ways above on the light rig to reach the back of the room. I used 1 monitor each at the drummer, guitarist, bassist and lead singer. All off axis because we used mostly super hyper cardoid mics. Everyone was professional and used to junky setups at clubs and bars, so very few cry babies. Just great shows. And I got a ton of recording and mixing jobs out of it.

Buy once cry once. You need to decide what is more important sounding good live or getting a killer recording of your mustang sally solo. BTW the tascam is probably even a worse choice than the zoom since it only has 2 aux outs.

Mackie's LM3204 is a Line Mixer with 16 stereo channels and 2 pairs of stereo outputs, hence the 3204. 4 Aux sends, but you can only select either 1 & 3 or 2&4 for each channel. 2 mic pres that can be patched into any line input. 3 band EQ on each channel, none on outputs.

I owned one and it was great for summing up 4 synths, 2 drum machines, 2 stereo guitar racks, but it would be a nightmare for live use. Also almost 10" deep and 5RU high, so meant for in a rack, definitely not tabletop.

FFS, for any decent kind of requirements, any reasonable contemporary digital mixer offers loads of inputs, loads of outputs, all the dynamics/EQ/effects that you'll ever need, full scene recall and recording. All that in one box is the point of a digital mixer. Just pick against your channel count and make sure you're happy with the interface/workflow.

Note, the above list of "standard" requirements precludes a few - Presonus StudioLive pre Series 3, QSC Touchmix, Zoom Livetrak, Yamaha 01v - all on full recall, as none have recallable headamps, and some lack other features too. Why anyone would buy such a neutered mixer, when there are so many full functionality desks at the budget end of the market, remains a mystery. They might sound a great idea to begin with, but you'll soon hit up against the limits - as the OP has, despite doing his best to defend his crappy Livetrak and telling people who know what's what that they're gear snobs. I'm no snob at all, but know that I don't want to be held back by lack of functionality.

I had moved up from a Mackie 1202 to a used Mackie 1642, dbx 231 30 band graphic EQ, dbx1040 quad limiter/gate, SPX90, MPX 500 and a massive rack case - and sold it all for a used 01v for $350. Night and day. Then sold that to move to a DL1608 - again night and day. No one needs to use budget analog anymore when used digital consoles are available.