Jump to content

Feedback issues


Recommended Posts

  • Members

Ok, another question concerning the sound at my church. After not having anything to do with the system for close to a month now, they have been having some issues. I told them I would assist some and see if I could figure out the mess that the sound company had created when setting the stuff up incorrectly.

 

First off, after using the built in crossovers in the amps, I switched to the Peavey 32fx built in crossover in sub mode. Running mono mains out of the right side and mono subs out the left. This was nice as now, I have overall sub volume control..

 

Also at the same time, I unhooked the 30 band eq from the mains because it was just being bypassed and when they set it up, they did a horrible job. The sound sounded better bypassed then when it was being used. I in turn adjusted the internal eq of the board to what seemed to sound the best.

 

I also have the feedback ferret turned on, inside the board as well.

 

Now we are having issues with one of the two wireless mics that we have. First off, it has had issues for a while, but they seem to have gotten a lot worse over the past 2-3 weeks and they are blaming them on me so I want to see if anything I might have done would have affected it. It is an old Audio-technica mic.. uses a new battery every service cause they constantly go dead. one of the two antennas is broke off the receiver.

 

I have told them it is time to upgrade their wireless mics. They dont like this opinion, but the last service, I had to keep muting the mic because either it was giving feedback every few minutes, or it would go from soft to loud. At one point I had the fader almost to the 0db line and it suddenly got way loud.. after I muted it to let it stop feeding back, I had to drop it almost to the lowest point before it wasting too loud.. Does this sound like it is just a bad mic and receiver? Forgive me if I haven't really included the info you need. I can try to get model numbers tomorrow night.

Link to comment
Share on other sites

  • Replies 50
  • Created
  • Last Reply
  • Members

Re-connect the 31-band EQ and learn how to use it properly. For every output that leaves the mixer, there should be a channel of 31-band EQ on it.

 

Set all the EQ faders flat, and have someone walk around with the wireless, to mimic an actual service. When it starts to feed back, try to find which frequency is the culprit... this gets easier with experience, but try cutting a frequency (say 1k) and if the feedback stops, leave it cut out. If it's still feeding back, bring the slider back up to 0 and try the next one. Keep doing this until you find the frequencies that are causing problems. Bring up the mic volume until it feeds back again, and repeat until your helper can walk around the room with adequate volume and no feedback.

Link to comment
Share on other sites

  • Members

Frankly you sound angry at the people in charge. I suggest you step away from the situation and examine what is going on and why you feel the way that you do.

 

After you figure this out I would start trying to troubleshoot whats going on. If the volume jumps only effect that one mic it sounds like either the mic or the channel is bad. Is this a lapel mic? First try switching to a new channel on the board, if it keeps happening and it's a lapel mic i would try swapping the actual microphone on the receiver. If the problem persists bring the wireless mic system in for repair or replace it.

 

Feedback is usually a sign of poor system deployment. Are the speakers behind the person talking? If this is a lapel system I suggest replacing the lapel with a headset style mic. They give you a MUCH more consistant signal and much higher gain before feedback. I think you need to approach this from a system solution rather than trying fix the problem by replacing random components or slapping band-aids on the problem.

 

Overall I think the most important thing is to check the attitude. If you exhibit the same attitude their that you are showing here, it's no wonder you are having troubles getting people to cooperate with you.

Link to comment
Share on other sites

  • Members

No I'm not angry. Not at all, but if only you knew their attitude towards me.. I did a month or so research on sound equipment, got several good quotes, one from a member on here.. all was nice equipment for the money.. They in turn shot me to the curb and went with a local company that in the end has screwed them over and so far has not impressed me one bit. That explains the attitude, it isn't toward them directly, more so toward the sound company they went with.

 

As far as the system setup, The three mains are being flown right above the edge of the stage, maybe a foot past, so the mic is behind the speakers. The mic itself is a hand held which dual purposes as the lead singer's mic as well as the pastors speaking mic.

Link to comment
Share on other sites

  • Members

Assuming there aren't any monitors, Mogwix's advice the proper process to follow. If you find you're pulling the EQ down too much, you may want to try an alternate mic in the same offending locations.

 

If there are monitors, you'll want to check their levels as well. If they aren't too loud, you'll have to run the same process on them to find the feedback frequencies.

 

As to the sudden volume changes, check the cables, snakes, wireless receiver jack, etc...

Link to comment
Share on other sites

  • Members

There are monitors, two main monitors, and several hot spots scattered about the stage.. They are not very loud though because we have one on pretty much every instrument so overall stage volume is relatively low.

 

All cables, snake and board are brand new.. The only thing used in this system was the mics and receivers.

 

I'll try the eq approach tomorrow if I get a chance.

Link to comment
Share on other sites

  • Members

 

As far as the system setup, The three mains are being flown right above the edge of the stage, maybe a foot past, so the mic is behind the speakers. The mic itself is a hand held which dual purposes as the lead singer's mic as well as the pastors speaking mic.

 

 

There is something wrong with the set-up or tuning of the system. Do you have a quality sound service company available that can walk through all the details and troubleshoot to discover what the REAL problems are?

Link to comment
Share on other sites

  • Members

I'm close to 75 miles from Little Rock, where I figure the best place would be located and even then I don't have a clue who it would be.. This local company that already set us up is the only one around that I know of. So I am pretty much on my own.. Even if there was someone else, We couldn't pay.. Their budget is already gone for the sound, so I am left trying to fix the mess they payed for.

Link to comment
Share on other sites

  • Members

You will maybe create more of a mess trying to fix it without knowing what you are doing rather than getting it done right.

 

What's with folks saving money trying to do it on the cheap then spending even more money trying to fix it on the cheap etc.

 

No wonder us pros are disgusted with the market??? Hmmmm.

Link to comment
Share on other sites

  • Members

I wish they would pay someone to do it. Heck I'd pay if I had the extra cash but with my upcoming wedding in less then 6 months, I'm saving my extra for that. But I totally agree that they need a professional. I am no way qualified to fix this, but all I can do it try to do it the best I can. I guarantee I can produce a higher quality sound then the company that installed it. It is just going to take some tweaking.

 

After getting everything setup the way it is, it sounds pretty good. I just have to fix this feedback issue and it will be pretty much done.

Link to comment
Share on other sites

  • Members

Looks like you've got two, maybe three separate issues.

 

The first is that something is wrong with either the wireless mic, gain structure or signal path.

 

One easy (but not foolproof) way to check is to simply switch the two receivers right at the start of your signal chain.

 

If the original offending mic still offends, then it's likely, the mic, receiver, interference, squelch control....

 

If the okay mic presents the same problems as the original bad one AND the "bad one" is now okay, then you can figure it's probably not the mic or receiver, but rather cables, channel and so on. Don't try this during a service...

 

Your second problem is the basic PA set-up. If you've got subs, and speakers behind the mics, you'll want to get that 31 band EQ working somehow. You'll need to learn how to ring the system out and set all your gains properly (if they aren't already).

 

Your third issue is that you are willing to work with substandard or broken equipment. You need to explain to them that you would be willing to help get things under control with wired mics, or functioning wireless, but you're not a magician. You can't make something broken, work, just because they want it that way. Only your Big Fella can and He helps those who help themselves.

 

Good luck.

Link to comment
Share on other sites

  • Members

 

No I'm not angry. Not at all, but if only you knew their attitude towards me.. I did a month or so research on sound equipment, got several good quotes, one from a member on here.. all was nice equipment for the money.. They in turn shot me to the curb and went with a local company that in the end has screwed them over and so far has not impressed me one bit. That explains the attitude, it isn't toward them directly, more so toward the sound company they went with.


As far as the system setup, The three mains are being flown right above the edge of the stage, maybe a foot past, so the mic is behind the speakers. The mic itself is a hand held which dual purposes as the lead singer's mic as well as the pastors speaking mic.

 

 

 

Gotcha, there is always room for interpretation in writing. If you go back and read what you wrote it does come across wrong and it does sound like you are frustrated with the decisions made by those in the church. I would counsel you to sit down with the folks in charge and calmly and rationally explain why you are frustrated. Hopefully you can make them see why the decision they made turned out badly and hopefully move toward a solution.

 

First, you need to isolate the issue. Just like Shaster said (and I said above) you need to figure out what is going wrong with the wireless mic / signal chain.

 

Next, when dealing with bad installs, one of the biggest issues is that there are a ton of things that could have been done wrong. What exact speakers/amps/processing do you have in the system? What are the settings on each piece of equipment?

Link to comment
Share on other sites

  • Members

Sounds like a plan, I havent had a chance to adjust the one that was there, but I'll make time..

 

Not that it is your problem, but I just purchased a 24fx and it is based off of the same design. I have read the manual a few times. In the manual it states that (I believe) if your using ( some ) wireless mic system and your phantom power at the same time it can cause damage to the mic systems and or board. Might be something to check into..................:wave:

Link to comment
Share on other sites

  • Members

Are you using the Feedback Ferret in "static" or "Dynamic" mode? I'm guessing static. Switch it to dynamic! I'm guessing that it will do a far better job than you could ever do with a GEQ.

 

Your problem is that every time you move your mic position the feedback center frequencies change. That pretty much makes a 31 band a poor tool to stop feedback.

 

Squelch, gain structure, phantom power have nothing to do with generating feedback. You are simply exceeding unity gain (which is ALWAYS the same reason anyone gets feedback)

Link to comment
Share on other sites

  • Members

 

Are you using the Feedback Ferret in "static" or "Dynamic" mode? I'm guessing static. Switch it to dynamic! I'm guessing that it will do a far better job than you could ever do with a GEQ.


Your problem is that every time you move your mic position the feedback center frequencies change. That pretty much makes a 31 band a poor tool to stop feedback.


Squelch, gain structure, phantom power have nothing to do with generating feedback. You are simply exceeding unity gain (which is ALWAYS the same reason anyone gets feedback)

 

 

Agreed, though it sounds like there may be something wrong with the mic that it making it's volume jump around, therefore exceeding the GBF unexpectadly without any user input. This seems to be the heart of the issue, and he needs to figure out what's causing it (bad capsule, transmitter, receiver or mixer channel).

Link to comment
Share on other sites

  • Members

 

Are you using the Feedback Ferret in "static" or "Dynamic" mode? I'm guessing static. Switch it to dynamic! I'm guessing that it will do a far better job than you could ever do with a GEQ.


Your problem is that every time you move your mic position the feedback center frequencies change. That pretty much makes a 31 band a poor tool to stop feedback.


Squelch, gain structure, phantom power have nothing to do with generating feedback. You are simply exceeding unity gain (which is ALWAYS the same reason anyone gets feedback)

 

 

Here is what I was referring to on Phantom Power.......not necessarily feedback but a problem with wirless mic damage. This is from the owners manual...

 

Phantom Power Switch

This switch applies +48 VDC voltage

to the input XLR connectors to power

condenser microphones requiring phantom

power. This switch is recessed into

the console and requires a small

Link to comment
Share on other sites

  • Members

 

Here is what I was referring to on Phantom Power.......not necessarily feedback but a problem with wirless mic damage. This is from the owners manual...

 

Phantom Power Switch

This switch applies +48 VDC voltage

to the input XLR connectors to power

condenser microphones requiring phantom

power. This switch is recessed into

the console and requires a small

Link to comment
Share on other sites

  • Members

 

Agreed, though it sounds like there may be something wrong with the mic that it making it's volume jump around, therefore exceeding the GBF unexpectadly without any user input. This seems to be the heart of the issue, and
he needs to figure out what's causing it (bad capsule, transmitter, receiver or mixer channel).

 

 

Couldn't it also be the result of interference from newly assigned users on the OP's "old" probably (700mhz) channel wireless?

 

I would also go back to using the amps or a dedicated real crossover instead of the one in the board. Having sub level control available at the board to relatively unskilled operators is not in my opinion a good thing.

 

Good luck, Winston.

Link to comment
Share on other sites

  • Members

It's like painting in the dark., the old internet diagnostic conundrum. Many of the suggestions presented here are in the "leave no stone unturned" category. But, one might as well have as many things right as one can. One of them might be the ticket.

 

And as Gregidon has pointed out, the mic is taking off suddenly. The OP can't operate a show without solving that.

 

Currently he's losing respect for a problem he (presumably) hasn't created.

Link to comment
Share on other sites

Archived

This topic is now archived and is closed to further replies.


×
×
  • Create New...