# Best mic for gain-before-feedback?



## madkayaker (Feb 14, 2007)

I'm doing a Battle of the Bands at the local high school in a month, and the sound system that we (the high school) have is notoriously prone to feedback. What sorts of microphones do people recommend for getting the best gain before feedback? I've heard various recommendations for the Crown CM-310A and the Audix OM7, but I wanted to know if anyone had any other suggestions, as well as experience in this sort of situation.

Also, in terms of other solutions for reducing feedback, what exists besides EQs (and fancy auto-feedback-reducing-EQ's) and just moving the microphones and speakers?


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## avkid (Feb 14, 2007)

This is way too general a question. What kind of setup do you have currently?
mics,cabs,mixer,processing?


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## Eboy87 (Feb 14, 2007)

To echo avkid's sentiments, what are you using this for? What are you using for monitors, and where?

To throw a few names out there, there's the stand-by of the Shure sm57 for guitar cabs and the sm58 for vocals. I've heard good things about audix's OM5, but I've never used them. If this is a quick "git 'er done" sort of deals, I'd avoid Sennheiser. Don't get me wrong, I love them to death, but they take a lot of TLC to get to sound good and not feed back, at least in my experience.


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## audioslavematt (Feb 14, 2007)

I pity your soul. I hope they pay you well. The Beta58A doesn't do too bad in terms of gain before feedback. If you're doing one wedge, put it right in front of the performer, if two, spread them out 45 degrees from the performer. Keep them as far behind the mains as you can. Run the gain up high enough that it rings. Figure out the frequency and dump it on the graphic EQs (or preferably parametrics if you have them). Do that again. I would dump as much of those frequencies as possible, because BOTB type events tend to draw every idiot band in the world and they'll insist on playing with their amps on 11 (been there done that). You'll have those wedges on the brink of ringing all night.


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## madkayaker (Feb 14, 2007)

Part of the problem is I'm not exactly sure what the setup's going to be... band's refuse to share amps/drums/keys, and the organizer won't make them. The rest of the gear will be either the school's (4 SM-58's, 2 JBL M-Pro 225's as mains, 4 nondescript JBL wedges, and amps) or borrowed (1 or 2 Yamaha 01v mixers, Countryman DIs, 2 Mackie SRM-450's for either mains or monitors, 2 audix shotguns, and 4 Audix CX-211's, as well as a Neumann KMS 104). For processing I'll have access to (in addition to the built in channel effects in the 01v, such as noise gates and compressors) 2 1/3 octave EQ's, as well as a 2-channel Sabine FBX unit with 1/3 octave EQ's. I'll probably end up using the Sabine on the main out as well as the vocal monitors, with the EQ's inserted on the drum monitors.

This is just my current thought-- as you can probably tell, I'm not actually a professional sound engineer (I actually go to the high school, but have done a large deal of sound with my father/through the school), so I don't have much of my own gear-- though I'd like to change that. I do, however, have access to some other gear, either through borrowing or renting, so any suggestions as to how to make the event sound best (and feed back least) would be welcome as well.


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## avkid (Feb 14, 2007)

I say make this as uncomplicated as possible, ditch the outboard processors and use the internal processing instead.


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## Eboy87 (Feb 14, 2007)

Studio Manager will definitly come in handy here. Get it at Yamaha's site, and download the 01V editor as well. 

p.s. sorry if that seems redundant and you already know that. I've jsut worked with far too many people who have no idea what the heck they're doing.


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## mbandgeek (Feb 14, 2007)

The best way to battle feedback is to ring out the system before the first performance.

I am not sure it ring out the system is the correct phrase, but take an RTA and a eq and get the most out of the system.


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## madkayaker (Feb 14, 2007)

Eboy, after examining Yamaha's site, I found studio Manager, but the link appears to be broken. http://www.yamahaproaudio.com/download/utility/index.html#scv2host
I also found something that yamaha calls the "CBX driver." I wasn't able to find the O1v editor.

Any idea where to find these?


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## Eboy87 (Feb 14, 2007)

Yeah, Yamaha has all the good SR products under Yamaha Commercial Audio. The link for the XP version of Studio Manager is here http://www.studioconnections.org/download/sm217w.zip
The Mac OSX version is here. (I don't know what OS you're running). http://www.studioconnections.org/download/sm218mx.zip
The 01V Editor is here, again, for XP and Mac respectively
http://www.yamahaproaudio.com/downloads/firm_soft/01v96/editor/edt213/01v96_edt213_win.zip
http://www.yamahaproaudio.com/downloads/firm_soft/01v96/editor/edt213/01v96_edt213_mac.zip
And the firmware is here (should you need it)
http://www.yamahaproaudio.com/downloads/firm_soft/01v96/01v96v2_frm.html
I got tired of doing it for each OS, but those links should work. I got these from this page, and I have those pages working in Safari
http://www.yamahaproaudio.com/downloads/firm_soft/index.html
Studio Manager is pretty cool once you get learn to get around in it. You can even set up parts of the show in advace, like channel assignments, what exf are going to be used, patching, etc., and then transfer them to the desk once you get to the venue. Let us know if you need more help


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## madkayaker (Feb 14, 2007)

Thanks so much, Eboy. With the time constraints we'll be operating under, this will go miles towards making my life easier. Again, thanks to all.


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## madkayaker (Feb 14, 2007)

One last question...will this utility only work for the O1v96, or will it work for the original 01v as well?


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## Eboy87 (Feb 14, 2007)

Uhh...good question. I assumed you were using the 01V96. I don't have an answer for that. You can try, but I'm sure someone will be along shortly to set the record straight.


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## SHARYNF (Feb 15, 2007)

TYPICALLY it is less of a mic issue, and more of a speaker placement or monitor placement. Keep the FOH speakers forward of the furthest area forward that a mic is going to be used, It is a very BAD idea in these types of setups to have the speakers aligned with the edge of the stage. Remember that if you angle the speakers inward that you are going to get some of the sound from speakers to be going on to the stage.

Make sure that the singers don't decide to drip the mic down to their side, this is typically what is done, with the mic right in front of the monitor.f

Fun fun fun

Sharyn


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## Eboy87 (Feb 15, 2007)

SHARYNF said:


> Make sure that the singers don't decide to drip the mic down to their side, this is typically what is done, with the mic right in front of the monitor.f
> Fun fun fun
> Sharyn



Oh, on that note, cupping the mic is bad. I realize trying to get screamo bands (or any high school band, with a few exceptions) to not cup the mic is like trying to teach a cat to speak Russian, but warn them that the wedges will squeal if they do.


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## Andy_Leviss (Feb 17, 2007)

madkayaker said:


> One last question...will this utility only work for the O1v96, or will it work for the original 01v as well?



Unfortunately not. The original came out long before Yamaha started supplying Studio Manager; there might be a third party manager (I know there was one, whose name I'm blanking on, for the 02R), but it might be hard to find these days, and might not be cheap.

Sorry 

--Andy


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## SHARYNF (Feb 19, 2007)

Here is the link for some control software, know it works with 03d and 02r not sure about anything else, it was from a company called c mexx
\ 
http://www.sfb.net/acatalog/C_Mexx.html 

Sharyn


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## tblan (Feb 19, 2007)

Consider splitting each signal before it comes into the board, send one channel to the mains and the other back through the monitors. This will give you more control over eq for the monitors vs. the mains and should help to manage feedback a bit better.


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## BenFranske (Feb 25, 2007)

A couple of things. First, as far as I know there is no Yamaha mixing software for the 01V; however there is third party mixing software for the 01V and the even older Promix 01 (a very early digital board from Yamaha) but I can't recall the manufacturer. Note that these older, pre-Ethernet boards require a MIDI port on the computer for control.

Secondly, while speaker placement, EQ, etc. can have a great impact on gain before feedback there IS a distinct difference between microphones. When I work in a difficult feedback environment my (dynamic) mics of choice are the Audix OM series, I have the most experience with the OM5 which is fantastic, I would expect at least as good a job from the OM7. For comparison, these are significantly better than the everpresent SM58. AudioTechnica also makes some good dynamic mics.


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## TimmyP1955 (Mar 25, 2007)

The CM311A is the go too mic for drummers and percussionists.

Otherwise the OM7 is the mic for feedback rejection. I also prefer its sound to any other dynamic I've tried so far.


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## Robert Linkroum (Dec 22, 2013)

Dear MadKayaker,
In your Battle of the Bands event, if different bands bring some or all of their own gear, the following is a stellar solution:
In addition to, or instead of, the "slash and burn" EQ solutions listed here, try first using a high quality Compressor / Limiter such as the DBX 1066 - about $ 500 USD (has XLR and quarter-inch In and Out connections with lots of status indicators to verify the different operational settings).
Music and vocals that have potential for wide variations in dynamic range will have momentary peaks that can send a sound reinforcement system into howling feedback.
The use of a Limiter to put a brick wall on the peaks will go far in reducing the peaks that can trigger feedback and place a ceiling on the overall sound for the seated audience.
This sound ceiling will be esecially helpful if a audio feed is going to a video camera.
If you choose to EQ the system, use an Automatic Feedback Supressor such as the Behringer Shark - about $100 USD (again XLR and quarter-inch In and Outs with multiple helpful indicators). Both the use of the Limiter and the Feedback Supressor work well in a unknown room and performance situation.
when correctly used, this audio trickery will work and do it in a invisible manor.
A quick check with the bands, may find that one of them has these devices already.
The Auto Feedback Supressor does the work of a deep notch Parametric EQ, but just does if faster and better. 
The audience will just remember a fun time without a hint of nasty feedback.
-Robert Linkroum
Belmont Shore, California 
("The Come As You Are Section" of Long Beach, CA)
310 951 9985


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## FMEng (Dec 22, 2013)

This thread is six years old. Not sure why it needs a response now. Controlling levels and peaks with a compressor/limiter will not reduce the chance for feedback. If that were true, it would be harder to drive a system into feedback with mics sitting on a quiet stage. It isn't hard to demonstrate that the same amount of gain will result in feedback regardless of the sound levels. Compression is an important tool, but using it actually makes it harder to control feedback, because the compressor is effectively turning up the gain when the loudness of the source is getting softer. It is like having an invisible hand pushing up the fader.


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## Floobydust (Dec 22, 2013)

Audix OM7 is a winner for my band gigs.

Very narrow pattern, so the performer has to be right on it.


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## museav (Dec 24, 2013)

Robert Linkroum said:


> In your Battle of the Bands event, if different bands bring some or all of their own gear, the following is a stellar solution:
> In addition to, or instead of, the "slash and burn" EQ solutions listed here, try first using a high quality Compressor / Limiter such as the DBX 1066 - about $ 500 USD (has XLR and quarter-inch In and Out connections with lots of status indicators to verify the different operational settings).
> Music and vocals that have potential for wide variations in dynamic range will have momentary peaks that can send a sound reinforcement system into howling feedback.
> The use of a Limiter to put a brick wall on the peaks will go far in reducing the peaks that can trigger feedback and place a ceiling on the overall sound for the seated audience.
> ...


Perhaps we should start with whether you are advocating inserting this gear on individual channels, subgroups or the overall mix as those could give quite different results.

Feedback is not a factor of dynamics or absolute level, it is a factor of having an electroacoustical loop gain of greater than 1. The typical situation that causes feedback is a microphone seeing a level from the sound system that is greater than the original source level at that same microphone, thus the sound 'loops' through the system buidling in level with each pass. As that can be a factor of many relative phase related issues, feedback also tends to be very frequency specific. However, whether the source level at a microphone is 120dB and the level from the system at the same mic 125dB or the source level is 40dB and the level from the system 45dB, there is the same 5dB above unity gain and thus the same susceptibility to feedback. Dynamics and absolute level are not really relevant unless they somehow also cause a change in the associated loop gain.

So a limiter may be able to limit the feedback level to whatever threshold level you have set but it won't avoid or elminate feedback. In addition, you have to watch how you use 'makeup' gain on a comp/limiter. If you compress or limit the peaks of the signal by some amount and then apply a makeup gain equal to that reduction you end up with the same peak levels but a greater average level. That may be good for getting a source up out of the mix but it may actually make a system more susceptible to feedback. So lots of good reasons to use a comp/limiter but avoiding feedback is not one of them.

An Automatic Feedback Suppressor usually works best if used on individual inputs, if assigned to the overall mix can affect the quality of the sound. I find that an AFS is too often used as a 'band aid' to treat feedback that occurs rather than trying to avoid feedback in the first place. An AFS may make it a great 'backup' to have in place for those unexpected situtations but you probably still want to maximize gain before feedback as much as you can without the Automatic Feedback Suppressor.


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