Graphic, Parametric, or Feedback Buster?

[JD]

Working with a choral group that tours and doing sound. Tricky, as I am singing as well. (Kind of reminds me of driving down a road with newspaper over the windshield.) In any case, always needing more gain and the ratios of microphone to speaker are not as good as I like. Old School in me would think about using a 31 band or a parametric to level out prone notches/peaks. Lots of people pushing the idea of using one of these "feedback busters" (Behringer FBQ1000, etc.) My concern is that in a choral group, some parts sung sound an awful lot like feedback! How easy are these things fooled into miss-setting themselves? My gut is telling me to stick with a graphic or parametric as I am pretty good at ID'ing frequencies, but hey, am I living in the past?
Just collecting thoughts. Stay old school with manual controls, or trust the new "magic box"?

 

[cbarrett92]

I agree with the 31 band. I've never been completely satisfied with the automatic feedback destroyers I've seen in use over the years.

But maybe I'm just missing the magic make/model...

 

[FMEng]

A graphic EQ is a response shaping tool, not very effective for controlling feedback. Feedback destroyers do work with some compromises in sound quality, as there is no free lunch. I'd rather apply some narrow notches with a feedback destroyer than heavily apply the wider filters of a graphic. I've used a Sabine FBX2410, and you can apply filters before the show starts and lock it, or let it adjust dynamically.

That said, I'd be looking more at how the mics are used to reduce feedback. Getting the mics closer to singers reduces the gain needed, even if it requires more mics. Sometimes, just careful arrangement of the singers around the mics works wonders. How many voices does the group have?

 

[JD]

About 30. Therein lies the problem. Four SM81's used overhead. Very small system. As we play some pretty odd locations as far as size and shape and usually have only 15 minutes to set up, we have to keep it simple. It is rare that we can even pull off a sound check, so often I have to fly by the seat of my pants and hope for the best. If we had FOH sound, then a parametric would do the trick as some of the problem points are easy to recognize. Problem is, I have to dive out of position usually in a dimly lit area to make any adjustments, so a graphic is a bit more visible even thought it doesn't give you the tight cut you can get on a parametric. I guess I have a hangup about turning it over to automation when it comes to a "feedback buster". All has been working pretty well, but the stage area (usually quite small) rapidly changes it's characteristics once you pack that many bodies in. Although I spent a lot of time in sound, that was over 25 years ago, so I figured it was time for a reality check to make sure I am not living in the past! Technology moves on, but the same old problem persists: Ask someone, and they will try to sell you whatever it is they are selling. Still, if the automation has become a mainstay, then I should be open to that.

 

[FMEng]

Interesting. I have worked at a venue that gets a lot of touring college and professional choirs around that size. I have yet to see one that would want any sound re-enforcement at all. Most conductors would flip their lid at the suggestion of such a thing. Even the larger, more skilled children's choirs shun mics. Once in awhile, a mic or two is used for solos or for an acoustic guitar, but that's all.

 

[sdauditorium]

I echo the same. For choral concerts, I do all I can to not mic the group. Unless there's a solo or acoustic guitar as noted above, the "less-is-more" treatment is preferential.

 

[JD]

Interesting. When I joined, it was SOP. The vocals do compete with piano, bass, drums accompaniment which changes the acoustic landscape. If it was a straight choir, then al-natural would make sense. Yes, solos etc., but they do a lot in the nursing home circuit (didn't even know there was one of those till I joined) and the rooms are usually very dead (acoustically speaking) , lots of cloth, carpets, etc that eat up sound. Have had far more complaints about people not being able to hear the shows than anything else (will leave out the hard-of-hearing comments.) Although the Bass is variable, drums and piano are not. They pace themselves pretty well, so it's not the "obnoxious musician" syndrome that we all know and love. As simple as their system is, it is a tricky balancing act. Some processing should give me the 3 to 6 Db edge that is lacking, thus the question. I figured I would donate what is needed since it is an all volunteer NPO, but am up in the air with the three choices.
(Picture of typical gig)

 

[robartsd]

Where are the speakers?

 

[JD]

Where are the speakers?

Out of view on that shot. Basic JBL stand speakers (older model, 12 and a horn, don't remember the model off hand.) Monitors are same vintage JBL, 10 and a horn, but only foldback the solo mic when used and the director's mic. In that shot they would be right of the drums and left of the piano. No problems on this gig, but we are often forced by room layout to locate them BEHIND the front mic line. Yea, such is life. Although it's really a processor question, I might as well fill in the other details; Behringer XENYX X2442USB mixer, QSC power amp. Did a gig that was so cramped last week, I had to put the mixer and amps under a Christmas tree! Improvement budget consists of the following, "open your mouth = open your wallet", so I'll stick with tweeks!

 

[TimmyP1955]

Parametric. In your situation, the 'crank it till it feeds back' would likely be OK (preferably with a little noise generation on stage such as clapping). Use an FFT app on your phone or pad to ID the frequencies for you (since with a tight parametric band, in the lower frequency bands you need to be within a few Hz).

 

[JD]

After careful consideration, I concur that the Parametric would be the best solution, that is why I went with a 31 band graphic
If I were running this FOH, it would be parametric hands down. What finally made my decision is that I will be running this thing from 8 feet away, so the visual is easier with the graphic. Beheringer (yea, I know) makes a graphic that illuminates the slider if there is a ring in that frequency. It does not alter anything, that is manual, but it is helpful. Since we are using JBL stand speakers, I have the roll-off set around 80Hz, so very low frequencies are not a big issue. The board itself has a single band Parametric on each channel so I can "slap the hand" of any quarrelsome peak. Thanks for the input everyone!

 

[Senorfish]

You're putting the four overhead SM81's all on the choir? I'd try cutting that down to just one SM81, or two if you feel like it needs it. But the group does not look very wide. Less mics will help with the gain before feedback equation, offers simplicity, and avoids phase issues.

I'd go with the 31 band graphic as well... more control. For a 15 minute sound check... set your gains just near the feedback threshold then one at a time pump each band on the graphic up to see if it rings. Cut proportionally per how much it's ringing. Start with the bass frequencies (after rolling off the very bottom) since bass frequencies have the most kinetic energy and tend to 'feed' the mathematic octaves above themselves with more feedback.

I had some self powered JBL Eons that were very unstable speakers and would whine all the time. Changed those out to QSC K12 speakers and the results were astounding.... a much more stable speaker.

And for any gig that you have to locate the speakers behind the mic line, I would just turn the whole thing off for best results.

Money permitting you could get a Berhinger X32 Compact or Producer digital console....(has graphic and parametric EQ's internally all in one package) and pair that with a 2nd or 3rd generation Ipad that would allow you to tune wirelessly from the stage.

 

[TimmyP1955]

The Behringer blinky lights tell you the relative levels of sound in each band. Ok for finding which band has a ring if everything is quiet, not so informative if something is close to taking off but hasn't yet.

 

[JD]

The Behringer blinky lights tell you the relative levels of sound in each band. Ok for finding which band has a ring if everything is quiet, not so informative if something is close to taking off but hasn't yet.

Yea, been playing around with it over the extended weekend. Looks like it will do the trick just fine. Behringer spooks me a bit because they are so cheap, yet so far, their other units have been holding up. Having spent 20 years in electronic service it's easy to see they are NOT service friendly and would have to be considered disposable for the most part. Always try to work with a "plan B" in mind if something goes down. The "blinky light" spectrum analyzer is what it is, and is ok for ring-out before a show. I go more by my ear identifying problem areas anyway.

 

[StradivariusBone]

Yea, been playing around with it over the extended weekend. Looks like it will do the trick just fine. Behringer spooks me a bit because they are so cheap, yet so far, their other units have been holding up. Having spent 20 years in electronic service it's easy to see they are NOT service friendly and would have to be considered disposable for the most part. Always try to work with a "plan B" in mind if something goes down. The "blinky light" spectrum analyzer is what it is, and is ok for ring-out before a show. I go more by my ear identifying problem areas anyway.

I've had decent luck w/ Behringer's EQs. Just don't drop them (they'll break) and don't let them overheat. I've got 2 that are sitting right now very happily inside a nice, safe rack and have been doing so for about two years.

 

[CanYouHearMeNow]

I was going to recommend getting a 31 band with the LEDs so good choice there. I was also going to mention the Sabine feedback destroyer with the option of running it before the show, but if you can't get a quiet room, it is not as nice. If you are just in a talking situation it can catch things, but a real EQ is a better solution.