I just installed a new mixer and remounded some speakers. The new mixer is a allen&heath and the speakers are ev250sx with a 2 moniters and a sub. The main speakers are controlled seperate from the moniter and the sub. One moniter is pointed at a choir and the other at pulpit. I get a ringing or backfeed from the moniter pointed at the pulpit. I can turn the volume down on the moniter and it stops but if I turn the mic down on the pulpit then its hard to hear the pastor. When I turn the volume down on the moniter then the choir cannot hear. Can the moniter pointed at the pulpit cause the ringing or is there something else.
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Sound system feedback&ringing
- Thread starter rkbean
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whoaru99
Epic Member
I'd guess that monitor pointed at the pulpit mic is the likely culprit.
I'd advise you to go to JBL's website and look at their white papers on PA system information. It's almost certain they have something that advises about feedback problems. Doesn't matter if your gear is JBL or not, the same principles pretty much apply to all of it.
JBL sound system design part 1
JBL sound system design part 2
There may be other relevant stuff there too.
I'd advise you to go to JBL's website and look at their white papers on PA system information. It's almost certain they have something that advises about feedback problems. Doesn't matter if your gear is JBL or not, the same principles pretty much apply to all of it.
JBL sound system design part 1
JBL sound system design part 2
There may be other relevant stuff there too.
Hi - my business is live sound, so hopefully I can help.
What you need to do is EQ out the ringing frequencies - that way you'll get a lot more level. Simplest way to do this is buy a standard 31-band graphic EQ, and 'insert' it over the monitor sends. You may find that the FOH boxes, if placed close to the mics, will still affect the mic even if they're facing away.
That should give you a decent amount of level!
Thanks
Mike
What you need to do is EQ out the ringing frequencies - that way you'll get a lot more level. Simplest way to do this is buy a standard 31-band graphic EQ, and 'insert' it over the monitor sends. You may find that the FOH boxes, if placed close to the mics, will still affect the mic even if they're facing away.
That should give you a decent amount of level!
Thanks
Mike
whoaru99
Epic Member
EQ might help, but if the approach must be to ring out the offending frequencies, a dedicated feedback eliminator device would be a better choice.
This sort of device is a PEQ that uses very narrow band filters to notch out the offending frequencies rather than the fairly broad band approach with a 1/3 octave GEQ.
Without regard to a product recommendation/endorsement, the Behringer FBQ2496 is the type of device to consider if the physical setup can't be adequately changed to eliminate the feedback. Similar devices are available from any number of different pro audio companies.
This sort of device is a PEQ that uses very narrow band filters to notch out the offending frequencies rather than the fairly broad band approach with a 1/3 octave GEQ.
Without regard to a product recommendation/endorsement, the Behringer FBQ2496 is the type of device to consider if the physical setup can't be adequately changed to eliminate the feedback. Similar devices are available from any number of different pro audio companies.
FalconEddy
Audio Mastering Engineer
Ok, first of all, you'll need to give us more information about the setup. There are just too many variables in live sound reinforcement that can create feedback issues.
- Does each monitor have it's own channel and level control? If not, they should.
- Are the monitors on the floor, flying from the ceiling, or pole stand mounted?
- What make and model are the monitors?
- Is the ringing always present when one monitor is pointed at the pulpit, or only when someone is speaking?
- Is the pulpit mic always open throughout the entire service? How is it positioned in regards to the monitor?
- Are all mics fixed, or do you also have handhelds, walk-arounds, and lavaliers?
- What make and model mics?
- Is the issue more pronounced when someone with a lavalier speaks at the pulpit? (e.g. minister/priest)
This will give me a start at a rough visualization of the setup, and perhaps an idea or two for a resolution to your feedback issue.
I also recommend a multiple notch filter type stereo feedback eliminator for this setup, one channel dedicated to each monitor.
. . Falcon
The moniters are ev250sx self amplified have their own volume control one the speaker with the main signal being controlled from the mixer. One moniter is on the floor facing away from the mic and the other is sitting on a table facing the mic. The pulpit mic is permatly mounted but shut down and a lavilier mic is used. The ringing happens when it is in use but stops when the volume to the moniter is turned down at the mixer.
It's more simple than EQing the system- move the speaker so it's not aimed at the mic. You'll need to find a better location for it. The system should be equalized anyway, but you won't have good sound if the speaker is aimed at the mic. If the mic is omni-directional, get a uni-directional one.
FalconEddy
Audio Mastering Engineer
Ok.
You have several things going on here.
First, is that the EV model you're using is actually the SxA250; NOT the Sx250. This self-powered model has both low and high frequency shelving EQ. Have you tried cranking down the 5K knob to see if that helps?
Second, the lavalier mic is most likely omni-directional. Although these are generally acceptable for live broadcast and theatrical applications, I've always found them to be a PITA for live sound reinforcement when a direct monitoring system is used in addition to the main FOH. A better choice is a cardioid lavalier mic like the Audio Technica AT831B (or MUCH better. . . a cardioid headset) to help control feedback issues. But, a headset isn't generally an option for a religious service application.
So, you need to identify the problem frequencies and drop them out of that pulpit monitor. Many omnidirectional proximity-type lavaliers reject a fair amount of background noise, but are also fine-tuned to boost high frequencies in a couple of places. This is done to compensate for muffling issues when worn under the clothing. But, if worn fully exposed, they start singing on their own fairly easily when exposed to a monitoring system speaker.
What make and model lavalier???
Do you currently have access to either a 31-band EQ or feedback eliminator?
Just tryin' to help and give you a little information at the same time.
. . Falcon
The EV are self amplified. I think the lavilier mic is a audio technic. The speaker at the pulpit is a self amplifed but not an EV. The one at pulpit was put there because the choir director could not hear the EV pointed at the choir. I have suggested a hearing aid for him. The speaker is usually pointed in the direction of the pulpit. I appreciate all the help. I have only been working with this for a couple of years so it is a learning experiance for me. I think the pulpit mic is omni directional.
bowtie427ss
Lunatic Member
In a nutshell.:yes:
But, since church sound systems are most often operated in anything but a "pro" environment by anyone but a "pro", this might be the exception where a stand alone feedback eliminator is the most ideal solution.
Just my .02 y'all understand...................
I think the best thing to do is list the needs of the pastor, choir director, choir and congregation. If any special needs exist, list them, too. House of Worship is an entire sub-industry of the audio business and many products are available for hard of hearing, mics, monitors, mixers, EQ, etc. Shure has a section on their website for this and I would think AT does, too. I agree with the recommendation for the AT 831 mic (make sure to have extra batteries). Reposition the speakers, use EQ/feedback eliminator properly and look at the area where this is happening. Is it carpeted or bare floor? Close to walls or far away? High ceiling or low?
FYI- if you see anyone slap the mic transmitter in their hand to remove the batteries, tell them that it will break. They don't like this and it's only a matter of time before the sound begins to cut out.
I worked for an audio contractor that did mostly LDS facilities and they had an electrical/audio engineer who designed the systems so the person at the mic could speak at a normal level. With Atlas 8" ceiling speakers (really nothing special, but properly placed), a parametric/graphic EQ and his JBL software, the goal was to be able for the congregation to hear the speaker at a normal level, without coloring their voice. The mics were cardioid, voice and music sounded great and once it was set up, there was no reason for anyone to do more than occasionally adjust the volume for loud or soft speakers. We could cup our hand around the mic only a few inches away and get no feedback but they also had treated the acoustics. Other than us, the engineer, the PM Manager (Preventive maintenance) or maybe a couple of trusted members, nobody had any access to the equipment racks. The cabinets were locked and in a locked room.
Bottom line, it can be done, without feedback issues but it will need to be addressed correctly. Details of the space, levels, needs and setting it up correctly are needed.
FalconEddy
Audio Mastering Engineer
Possibly. . .
BUT, you have so much conflicting information here in your replies that it's hard to get a handle on this.
You've stated that the pulpit monitor is an 'ev250sx' (not an accurate model number), but also stated later that it's NOT an EV powered monitor. :scratch2:
Also, you've stated the pulpit mic is permanently mounted, but shut down. In another reply you said it's turned on when others speak from there (but, not for the pastor). Is THIS the mic that's ringing, and not the lavalier from the pastor? Or, does it only ring when the pastor is up there and both lavalier and fixed mic's are on? What make and model is the fixed pulpit mic?
Plus, you've also recently stated that the monitor at the pulpit is usually pointed in that direction. Which, to me, says it's getting moved around at some point during services. If true, that's also a problem.
Additionally, this is a set of unmatched powered monitors that are being daisy chained off a single feed from one channel on the A&H board; which is also feeding a subwoofer first. I'm guessing the subwoofer is also powered.
Have I omitted anything, or pictured this installation incorrectly?
. . Falcon
signal-dude
Just one good watt.......
"BUT, you have so much conflicting information here in your replies that it's hard to get a handle on this."
It sounds to me like he really needs a PRO sound guy in there to have a look around and offer some suggestions to fix the problem. This does not sound like something that can be fixed over the phone so to speak.
I run the sound for my church and we had a Pro come in to design and set up the system. Including the Behringer feedback eliminator, model escapes me at the moment.
And even with all this I still fight with the darn omni choir mics that squeal at the slightest wrong setting on the mixer.
It sounds to me like he really needs a PRO sound guy in there to have a look around and offer some suggestions to fix the problem. This does not sound like something that can be fixed over the phone so to speak.
I run the sound for my church and we had a Pro come in to design and set up the system. Including the Behringer feedback eliminator, model escapes me at the moment.
And even with all this I still fight with the darn omni choir mics that squeal at the slightest wrong setting on the mixer.
For recording a choir with the intention of picking up the ambiance, omni mics are great but for sound reinforcement, cardioid is much better. You may need to add one or more, but you'll have far less problem with feedback.