Live Channel-by-Channel sound canceling?

[kwelch007]

Hi Folks,

 

Thanks in advance for any suggestions you might be able to make!

 

I'm a live-music sound-guy in Central Illinois...I work primarily for a regional band called "90's Daughter," but you know how it is...you always end up doing other gigs. However, my question regards that band.

 

Basically, my problem is that our drummer is a hard hitter, and his stage noise comes through the vocal mics something fierce. He's literally louder in our singer's mic than she is. (And yes, we have a drum-shield.) What I'm trying to find is something that I can use to "cancel" noise selectively between mics, live. Basically, I'd like to tell this theoretical processor or whatever "if you're picking up the same sound in the vocal mic channel that you're getting from the snare mic, cancel the snare out of the vocal mic." I know my recording software will do this, but I'm not sure how to do it live.

 

FYI - here's info on the PA I generally use:

 

- 4-Piece Band...6 piece drum kit with a sample pad. Usually run an overhead due to the shield, bu rarely use it or the snare mic due to this problem. Basically, I'm "over the drums."

 

- I run everything into an Aviom A16II Personal Mixer system for their wireless in-ears (which is part of the problem...my singers don't even have any drums in their mix, but they come through their mics so loud that it hurts them.)

 

- Out from the Aviom to the snake and, generally, into a A&H MixWiz16 (occasionally into a Yamaha O1V) or whatever I end up with that night...you know how that goes. Pretty simple and standard effects rack.

 

- Back into the snake, through a crossover and into the amps, and then to dual15"+2-1/2" trumpet tops (Peavey SP4's I think) and single 18" subs (SP-118's maybe? Forget.)

 

Obviously, the ideal way to fix this would be to just get the drummer to play softer, which we've tried, but he just can't do it. So, I've gotta figure something else out. And, it's gotta happen before it gets to the Avioms, so I don't think anything FOH is really gonna solve my problem, but I could be wrong.

 

Any ideas would be appreciated!

Thanks!

Kendell

[dbuckley]

Point your drummer here.

 

You can't fix this problem with the PA.

[Stuart91]

One possible line of improvement is to try different vocal mics. The Audix OM7 in particular has a very tight pickup pattern, and will pick up far less of the drums than, say, an SM58. However it will only work effectively if your vocalist can stay close on the mic.

[Tony Lake]

a drummer hitting lighter always helps. If you have a good working relationship with the band that would be a good start. There have been times where I've been doing monitors and that has been "no go" territory though, so here's a few other ideas.

 

Different mics are a good option: if your using anything cardioid like a 58, this won't massively help, although, if a hyper-cardioid (say a B57,) was head on with the snare drum, then your problem may get worse.

 

SO:

 

if you go for a mic with a tighter pick-up pattern, make sure the microphone isn't head on with the drum kit. IDEALLY if the stage is large enough, stagger the drums and lead vocal either side of centre stage, this will help the spill a bit, angle the mic away from the drum kit as far as you can get away with as well.

 

I've tried all kinds on fancy phase inverting tricks for iems, to help with lots of drum bleed, especially with lots of vocal mics on stage. VERY rarely have I found phase inverting microphones helps in most live situations. My theory is that there are simply to many reflections going on. we've all had the physics class demonstrating how superposition of sound waves works, but I can only speculate the math get pretty complicated if you start taking multiple sources, RT60's and absorption coefficients into account.

 

ANYWAY

try to get as much air between the vocal mic and the drumset as possible. that'll help. and also live, (especially in smaller places,) I find with issues like this, fairly aggressive EQ to notch the beans out of the snare in the vocal microphone will help.

 

one other thing you could do is take a heavy curtain of something of the sort around with you, to go around the edge of whatever stage your playing. it's a bit of a pain and might be impractical in some venues, but I guarantee it will make the stage a bit quieter, and essentially it sounds like that's the battle your fighting.

 

 

Please excuse any spelling errors, It's late, but you get the idea I'm sure!

 

Tony

[Bobbsy]

A big +1 for Stuart91's suggestion of using OM7 mics for vocals. I've got a couple in the mic box and use them as my go to solution when I have a problem of high stage noise, whatever the source. (It tends to be 50/50 lead guitarists and drummers.)

 

To give an example of the usefulness of the OM7, I've used it in that horror situation where an over-loud drummer also wants to sing. The OM7 gave very usable results!

 

The other thing I always try is hitting the polarity reverse switch on the mixer. Sometimes it does nothing, other times it helps--so always worth playing with.

[S&L]

+1 for getting a drummer who can volume control and pick an appropriate kit/snare for the gig - but often you are stuck with the drummer and not in a position to be able to influence the gear he uses - particularly when you are starting out with the band

+1 for ditching the 58's and going for an audix. more often than not I'm working on tight bar stages - an OM2 will still give a better control than a 58 and then as you go up in audix spec the mic control gets better. for female vocalists I also keep a focusrite voicemaster platinum in the rack to insert into her channel. on bad snare days I engage the gate - meanwhile the compression and the eq tailor an otherwise slightly thin female voice to fill out and project better,

I won't give 58's house room if I have a choice. my front line for bars is a mixture of Audix and red5, there are plenty of other decent mics you can try (sennheisser e845, old AKG D880 etc.) but 58's are the worst offenders.

[Dave SA]

OM7 as suggested.

[mervaka]

This is considered very unorthodox these days, but differential microphone techniques were once used to remedy this same problem. Two identical mics placed within inches of each other, and the vocalist uses one. The second mic's signal is subtracted from the first, leaving (hopefully) only the desired signal.

 

Hopefully we'll see this make a comeback soon, perhaps as mics with an integrated second transducer and some DSP?

[mackerr]

This is considered very unorthodox these days, but differential microphone techniques were once used to remedy this same problem. Two identical mics placed within inches of each other, and the vocalist uses one. The second mic's signal is subtracted from the first, leaving (hopefully) only the desired signal.

 

Hopefully we'll see this make a comeback soon, perhaps as mics with an integrated second transducer and some DSP?

 

Like this one?

 

http://www.akg.com/site/products/powerslave,id,1095,pid,1095,nodeid,2,_language,EN.html

 

Mac

[GaryNattrass]

Never heard of anti phasing being used in PA applications and question if it would actually do anything as it would cancel out the vocalist too, in the old days it was pre mic splitters with one mic for the PA and the other for monitors or more likely for recording purposes!

[Richard P-W]

Differential vocal mics, in a famous application.

 

http://www.dozin.com/wallofsound/index.html

[Brian]

Never heard of anti phasing being used in PA applications...

Really? It used to be quite common. I don't have time to go and dig through the library downstairs but it's in a couple of older books I've got and IIRC I've seen an old app note from someone like Shure on it along with some transformer-based 2-in, 1-out boxes to do the anti-phase mix for you.

 

 

[E2A]

In fact, the AKG D222 had two separate capsules inside connected in anti-phase to improve the rear rejection.

[GaryNattrass]

Rear rejection is one thing and a totally different design but putting two identical mic's side by side with one out of phase is pure bunkum and will cause more problems than it's worth!

 

Sorry if I have mis-understood but I doubt if phase cancellation is a quick fix for a loud drummer, we have hypercardioid vocal mics to help in this situation and it's more about the right mic for the right job.

[nb705]

If you'd have read the linked article, two phase reversed mics with a small seperation is not bunkum, but has been used successfully in the past for reducing noise from unwanted sources.

[alistermorton]

In the photographs of the famous Stones gig at Hyde park Mick is shown using two mics taped together, with the business ends pointing in opposite directions. Is this for differential noise cancelling?

 

http://i2.mail.com/822/1691822,h=425,pd=1,w=620.jpg