SOLVED: Audio problem - HELP!

A long term solution would be to use one of the auxiliary mix buses on your mixer (I believe there are two on your model) to feed the choir's monitor speaker. This would require a separate (probably small) power amplifier for the choir speaker. You could send them sound from the preacher's microphone without mixing in the choir mics or any others that might be active, and you could turn it down while they're singing to completely silence that speaker as a source of feedback. That's the kind of thing those auxiliary mix channels were designed to do.

- Greg
 
Greg Smith said:
A long term solution would be to use one of the auxiliary mix buses on your mixer (I believe there are two on your model) to feed the choir's monitor speaker. This would require a separate (probably small) power amplifier for the choir speaker. You could send them sound from the preacher's microphone without mixing in the choir mics or any others that might be active, and you could turn it down while they're singing to completely silence that speaker as a source of feedback. That's the kind of thing those auxiliary mix channels were designed to do.

- Greg
Click to expand...

True, but again that requires doing a cable run through the high ceiling of our sanctuary. Hard to get anyone do to that, and I'm not able to do it myself.
 
If you really can't control the choir monitor speaker separately, then I can see why the previous guy said the next-best solution is to just disconnect it.
It sounds like it is seriously compromising the ability of the system to deliver sound to the primary audience, the congregation.
 
Richard Crowley said:
If you really can't control the choir monitor speaker separately, then I can see why the previous guy said the next-best solution is to just disconnect it.
It sounds like it is seriously compromising the ability of the system to deliver sound to the primary audience, the congregation.
Click to expand...

Totally agree.

I've just been informed that there is a SECOND amplifier. It's located in a closet at the opposite end of the sanctuary from where our setup is. There are conflicting reports from people who are just guessing as to what it does. My guess is that it controls that one speaker pointed at the choir, and isn't connected to our system at all. I'm going to go investigate. Let you know what I learn.
 
I found out what the 2nd amplifier does. As I suspected, it connects the mics which hang over the choir loft to the speaker which is pointed at the choir loft, so the choir can better hear themselves singing.

It's not directly tied into our mixer and amp, although those same mics are connected to our mixer. I'm not sure how all of that is wired together. I do know now that the speaker aimed at the choir loft is not connected to our system at all, but only to that second amplifier.

Good to know.
 
David W. Richardson said:
I found out what the 2nd amplifier does. As I suspected, it connects the mics which hang over the choir loft to the speaker which is pointed at the choir loft, so the choir can better hear themselves singing.
Click to expand...

WOW! It would be difficult to find a better way of sabotaging the sound system if you really worked at it!

Your system sounds like it was cobbled together by people who didn't really know what they were doing or what the overall consequences would be.

My deepest condolences. That wouldn't last until next week if it were under my control.
 
Richard Crowley said:
WOW! It would be difficult to find a better way of sabotaging the sound system if you really worked at it!
Click to expand...

My thoughts exactly.

Your system sounds like it was cobbled together by people who didn't really know what they were doing or what the overall consequences would be.
Click to expand...

I believe that's exactly what happened.

My deepest condolences. That wouldn't last until next week if it were under my control.
Click to expand...

Well feel free to come down here and fix it. :-)

I'll have to do the best I can, learning as I go. But there's no way I can climb a tall, tall ladder to get into the ceiling to follow wires if need be. So I hope to Heaven that all the connections were made at ground level.

BTW, I have ordered the -33dB attenuating cable. Should be here in a couple of days. Hoping for the best.
 
On a related (maybe) note, someone used a term with me the other day that I had never heard before, and am having a hard time understanding how to apply it.

What can anyone tell me about the concept of 'unity gain'? In layman's terms, please. Maybe mentally-challenged layman's terms. :-)
 
"Unity" gain would refer to an audio stage or amplifier adjusted so that the output level is equal to the input level; it has a "gain" of 1.0, or 0 dB. An amplifier specifically designed this way could be used as an isolating buffer between stages of a device, or to match impedances, or it might just be a marking on the gain knob of a mixer indicating where the input and output levels are the same.

- Greg
 
Greg Smith said:
"Unity" gain would refer to an audio stage or amplifier adjusted so that the output level is equal to the input level; it has a "gain" of 1.0, or 0 dB. An amplifier specifically designed this way could be used as an isolating buffer between stages of a device, or to match impedances, or it might just be a marking on the gain knob of a mixer indicating where the input and output levels are the same.

- Greg
Click to expand...

Okay....I understood a percentage of that.

If a mixer has numerous inputs, they can't all be coming in at the exact same level, right? So how does one make this work in the real world when you have a mixer into which run 3 cabled mics, 3 wireless mics, and a CD player, and which feeds a PA amplifier that runs a single speaker, while also feeding audio outs to a camcorder, a DVD recorder, and an RF modulator which sends the signal via coax to multiple TV's in an adjacent building? Oh, and also outputs to a wireless transmitter?
 
Unity often is used to refer to a particular stage of the audio chain. So for instance Mackie mixers have a U marking for unity for the fader. In this case you may well have a lot of amplification going on with the mic preamp at the input stage but at the fader level you are just passing the signal through. In theory and usually in practice unity of a fader is the point where you get the least noise (from that section). So if you have really good mic pres and they are giving you enough gain you can have a fader at close to unity and you are not adding more noise to the signal.

On most mixers you generally have three places where you can add gain to the signal. The input "trim" or mic preamp, the channel fader, and the output fader. Generally the gain on the mic pre/ channel trim is "cleaner" than the gain on the other two, though the reality can vary a lot. It's a safe assumption though on any decent board. They are expecting you to set up the trims so that everything else is getting a healthy signal and that faders are going to be used mostly for lowering levels. Masters are generally set up to balance out speaker set ups or just left at unity. Anyway, neither are designed to do a lot of gain so it's not the place to be adding it if you can avoid it.


It's very weird to me that you choir can't hear themselves, if they had a hard time hearing the organ maybe but?

I did work for a theatre that had been so treated to deaden it that when we did (rarely) do something with live music or singing we had to ring the stage with monitors because they "couldn't hear themselves". They could of course but they had a hard time because they were not getting the bounce off the back wall.

Smaller church setups tend to be hell (and how ironic is that!). I will mention that my brother in law was sort of in your position. For some reason he agreed to "fix" the sound system at his church. It was an insane set up and they were getting into feedback all the time. he lives a couple of thousand miles away so I only saw the place once. Anyway as much as it will make some cringe the solution that worked for him/ them was to get a couple of the Behringer feedback eliminators. The little boxes also did some level balancing so the system over all worked much better for them.

This is NOT the "proper" solution in that it's kind of a band aid that lets them ignore the problem but it fit the budget and it's basically a set and forget setup so that also fit the skill level of the various folks who were helping out.

I've worked on everything from mega budget films to small theatres where the lighting was clip lights controlled from household dimmers and hung on PVC pipes. Sometimes the proper solution is just not going to happen so whatever works is what you have to go for.

That said I would stick two asterisks on the above. It is really useful to know what the problem actually is even if you can't actually fix it. It will make your kluged solution work better and let you trouble shoot a LOT faster when it eventually fails. And every effort should be made to come up with a robust kludge so you are not having to constantly "fix" it.

If you can get your levels sorted out then something like the feedback eliminators may let you reconnect the choir monitors. I didn't see how this is set up but if it's just a monitor FOR the choir then you should be able to position the mics so you are not creating feedback loops. As you can geter in sound "loops" are usually a bad thing ;~)
 
Your Spirit Folio 10 2 has a red knob at the top of each input strip named "GAIN".
Because various sources are coming in at various "nominal" levels, the "GAIN" control is provided to "equalize" or "normalize" the different source signal levels.

Notice also that the mixing slider controls at the bottom of each input strip have a spot about 3/4 full travel which is labeled "0".
0dB means no gain and no attenuation (i.e. "unity" or multiplication by 1 which is the "design point" of the mixer.

Ideally, we set the "GAIN" controls so that with the mixer sliders at "0", we get the perfect signal levels.
Then, with the main output sliders set around the same place (around -"10" on the scale)
you should be seeing "nominal" audio indication on the LED-ladder meters.

The average audio level (for example when someone is speaking) I would expect to be varying up and down between -15 and -6 (dB)
With peaks hitting the "0" (dB) many times per minute. And occasional peaks well up into the yellow region.
If peaks are constantly exceeding "0" (dB), then it is time to reduce the "GAIN" on that input strip.

And, conversely, if peaks are rarely making it up to -3 or even -6, then it is time to bump up the "GAIN" control for that source.

Of course, common sense should be applied as well, the level indicator can't replace the intelligent hearing of the operator.
It doesn't make sense to over-amplify something naturally quiet, nor to let a very loud sound overwhelm the system.

When the input strip mixer slider is at "0", it is said to be at "unity gain".
Any number HIGHER than 0 incidates that "gain" is being added into the system.
And a number LOWER than 0 incidates that "attenuation" is being done to the signal.

Some mixers have the main sliders marked like the input mixer sliders on your unit.
When the channel input mixing slider is at "0" and the main "mix" pots are set to their nominal position, the mixer path (from input to output) is said to have "unity gain".

Setting EACH piece of gear in the signal path INDEPENDENTLY to its optimal operating levels is an important part of system design, installation, integration and operation.
It is called "gain staging". So that each link in the chain is operating at their optimum point of maximum signal-to-noise ratio.
 
Richard Crowley said:
Your Spirit Folio 10 2 has a red knob at the top of each input strip named "GAIN".
Because various sources are coming in at various "nominal" levels, the "GAIN" control is provided to "equalize" or "normalize" the different source signal levels.

Notice also that the mixing slider controls at the bottom of each input strip have a spot about 3/4 full travel which is labeled "0".
0dB means no gain and no attenuation (i.e. "unity" or multiplication by 1 which is the "design point" of the mixer.

Ideally, we set the "GAIN" controls so that with the mixer sliders at "0", we get the perfect signal levels.
Then, with the main output sliders set around the same place (around -"10" on the scale)
you should be seeing "nominal" audio indication on the LED-ladder meters.

The average audio level (for example when someone is speaking) I would expect to be varying up and down between -15 and -6 (dB)
With peaks hitting the "0" (dB) many times per minute. And occasional peaks well up into the yellow region.
If peaks are constantly exceeding "0" (dB), then it is time to reduce the "GAIN" on that input strip.

And, conversely, if peaks are rarely making it up to -3 or even -6, then it is time to bump up the "GAIN" control for that source.

Of course, common sense should be applied as well, the level indicator can't replace the intelligent hearing of the operator.
It doesn't make sense to over-amplify something naturally quiet, nor to let a very loud sound overwhelm the system.

When the input strip mixer slider is at "0", it is said to be at "unity gain".
Any number HIGHER than 0 incidates that "gain" is being added into the system.
And a number LOWER than 0 incidates that "attenuation" is being done to the signal.

Some mixers have the main sliders marked like the input mixer sliders on your unit.
When the channel input mixing slider is at "0" and the main "mix" pots are set to their nominal position, the mixer path (from input to output) is said to have "unity gain".

Setting EACH piece of gear in the signal path INDEPENDENTLY to its optimal operating levels is an important part of system design, installation, integration and operation.
It is called "gain staging". So that each link in the chain is operating at their optimum point of maximum signal-to-noise ratio.
Click to expand...

THANK YOU!!!!

Not only did I understand that, but I think I can now actually go and APPLY it!

Just so you know, we don't have the Folio 10 2 anymore -- we replaced it with the very similar Soundcraft ECM-8. Controls are almost identical, so this helps a LOT!
 
Noiz2 said:
It's very weird to me that you choir can't hear themselves, if they had a hard time hearing the organ maybe but?
Click to expand...

Well I've stood in that choir loft and spoken loudly, both with the second amplifier ON and also OFF. There is a distinct difference. Keep in mind that quite a few of the choir members are pretty old and their hearing might not be the best. I don't know exactly what the reasoning was for doing it.

The second amplifier can be turned off, of course, which will eliminate that speaker that points at the choir. I really don't think we have a serious feedback problem because of that amp, though. Not based on my experimentation the last couple of days. I've had stuff running pretty loud over the main speaker -- much louder than would be normal during a service -- and I've noticed no feedback issues.

Thanks again for all the help!
 
Another thing. I suspect the amplifier is connected to the mixer incorrectly.

Currently it's connected via a 1/4" that runs from the L MONITOR output of the mixer to the HIGH Z (Channel 2) input on the amplifier. But if I'm reading the mixer's manual correctly, the amplifier should be connected to the XLR (MIX-L and MIX-R) jacks on the mixer. Is that right? If so, what input on the amplifier should it connect to?
 
If the choir foldback amplifier/speaker only has the choir mics feeding into it, then how is it feeding the other PA system sounds (such as the pastor's sermon, etc.) back to the choir?
Perhaps we don't know everything about how things are arranged yet.
 
David W. Richardson said:
Another thing. I suspect the amplifier is connected to the mixer incorrectly.

Currently it's connected via a 1/4" that runs from the L MONITOR output of the mixer to the HIGH Z (Channel 2) input on the amplifier. But if I'm reading the mixer's manual correctly, the amplifier should be connected to the XLR (MIX-L and MIX-R) jacks on the mixer. Is that right? If so, what input on the amplifier should it connect to?
Click to expand...

I would use the "MIX-L" output from the Soundcraft EPM8 mixer.
(And leave the "PAN" pots on all the inputs set to the Center position.)

I would connect that "MIX-L" ouptut to the "PWR.AMP" input on the Peavy XR600C amplifier.

Unfortunately, the pittiful manual I found gives us NO information about levels, impedance, or balancing.
http://assets.peavey.com/literature/manuals/80301434.pdf
There is a former Peavey engineer (John Roberts) over on another discussion board (GearSlutz) who may have access to proper info.

I would try a proper XLR-F (female) to male 1/4 inch TRS (balanced) cable first.
But it seems quite possible that the "PWR.AMP" input is unbalanced, so be prepared to use an XLR-F to TS (unbalanced) plug.

With input audio hitting the mixer meter at "nominal" levels, set the gain control on the Peavey amp for "normal" sound levels in the audience area.
Remember that "normal" for an empty room is not necessarily the same as with the congregation in place.
 
Richard Crowley said:
If the choir foldback amplifier/speaker only has the choir mics feeding into it, then how is it feeding the other PA system sounds (such as the pastor's sermon, etc.) back to the choir?
Perhaps we don't know everything about how things are arranged yet.
Click to expand...

I don't believe it IS feeding any other sounds back to the choir. The only inputs connected to that amplifier are the 4 mics suspended above the choir. The piano and organ both sit right in front of them, so I doubt they have any problem hearing those. I don't know if they hear the preacher well or not. I'll ask my wife -- she's in the choir. :-)
 
Richard Crowley said:
I would use the "MIX-L" output from the Soundcraft EPM8 mixer.
(And leave the "PAN" pots on all the inputs set to the Center position.)

I would connect that "MIX-L" ouptut to the "PWR.AMP" input on the Peavy XR600C amplifier.

Unfortunately, the pittiful manual I found gives us NO information about levels, impedance, or balancing.
http://assets.peavey.com/literature/manuals/80301434.pdf
There is a former Peavey engineer (John Roberts) over on another discussion board (GearSlutz) who may have access to proper info.

I would try a proper XLR-F (female) to male 1/4 inch TRS (balanced) cable first.
But it seems quite possible that the "PWR.AMP" input is unbalanced, so be prepared to use an XLR-F to TS (unbalanced) plug.

With input audio hitting the mixer meter at "nominal" levels, set the gain control on the Peavey amp for "normal" sound levels in the audience area.
Remember that "normal" for an empty room is not necessarily the same as with the congregation in place.
Click to expand...

Yeah, that's the same pitiful manual that I've found.

I'd really like to know which is the right cable before I buy it. It starts to get expensive buying cables just to see if they are the right ones.

FYI, with the mixer-to-amp cabling as it currently is, the amp's "MAIN MASTER" gain can only be set to 1. Any more is much too loud. So clearly that's not optimal. Probably not "unity". :-)
 
Richard Crowley said:
I would use the "MIX-L" output from the Soundcraft EPM8 mixer.
(And leave the "PAN" pots on all the inputs set to the Center position.)

I would connect that "MIX-L" ouptut to the "PWR.AMP" input on the Peavy XR600C amplifier.

Unfortunately, the pittiful manual I found gives us NO information about levels, impedance, or balancing.
http://assets.peavey.com/literature/manuals/80301434.pdf
There is a former Peavey engineer (John Roberts) over on another discussion board (GearSlutz) who may have access to proper info.

I would try a proper XLR-F (female) to male 1/4 inch TRS (balanced) cable first.
But it seems quite possible that the "PWR.AMP" input is unbalanced, so be prepared to use an XLR-F to TS (unbalanced) plug.

With input audio hitting the mixer meter at "nominal" levels, set the gain control on the Peavey amp for "normal" sound levels in the audience area.
Remember that "normal" for an empty room is not necessarily the same as with the congregation in place.
Click to expand...

So this cable then?

http://www.amazon.com/Hosa-Cable-ST...=1444252505&sr=8-26&keywords=xlr+to+1/4+cable
 
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