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Church and H.O.W. – Forums for HOW Sound and AV - Your Displayed Name Must Be Your Real Full Name To Post In The Church and HOW Forums => Church Sound => Topic started by: Billy Snody on January 27, 2017, 05:32:08 PM
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Good day sir.
My name is Billy Snody. I saw some of your posts on a pro sound web forum and was hoping to get some ideas. I am a rookie chasing a “wabbit.” I am working on chasing an intermittent muting of the house channels in our Church. I am new to this and am tackling it because I am tired of it occurring. I live in a spot in a chug hole with no one to turn to for assistance. The company that sold and installed us is out of business. Our system is about five years old and started this “muting” activity about a year and a half ago and is getting more frequent. We have an Allen Heath GL2400-32 mixer, XLR “M” is outputting to a Sabine NAV 360, input 1 only, (nothing from mixer L or R which makes little sense to me) and nothing to input 2 or 3 on the Sabine. So one input to the DSP. From there it sends channel 1 and 2 out to a QSC RMX1850HD amp in stereo and then to house speakers hanging way up in ceiling, 2 paralleled (3.3 ohms on dvom)on one channel flanking the center speaker (5.7 ohms on dvom)wired solo on the other. Mixer AUX 1 and 2 go out on TRS connections into XLR’s plugging into a DBX 231 EQ whose outputs feed a QSC RMX1450 in stereo to the 3 stage monitors through floor boxes for I/O. My quandary is that the Sabine only has the 1 input connected but it has 3 outputs connected. I just got software for the Sabine and am sure it is going to blow my mind when I connect and see what this is all about. By the way, the input and output connections on the Sabine are all bare wires into small multi-terminal connectors (Phoenix connectors maybe). Output 1 and 2 got to the main (FOH) amp. Output three is a cable bundled with our 2 main speaker wires to somewhere/something that I have yet to determine. Our organ outputs to a passive x-over network with its own speaker array. Might you have any suggestions what I should look for to find out what this third output is connected to, even if I have to go up into the ceiling. We have no subs anywhere. We do have a lighting control box for some stage lighting that is also malfunctioning but I have found nothing but a power wire and a control wire that leads up to the power packs plugged into that controller. I have sent the FOH amp to a QSC authorized repair center for a diagnosis, a physical so to speak. I moved the inputs and outputs from the house amp to the monitor amp and my muting followed my move. I wanted to make sure the house amp had not been damaged. We have a Furman PS8R 15 amp sequencer and an M-8X2 conditioner for supply. They are on a 20 amp breaker. QSC tech’s and Furman told me all should be well as far as electrical supply goes. I was trying to bypass the Sabine but with only 1 output “M” from the mixer I don’t know if it is safe to drive an amp on only one channel at a time. Have you ever heard of a DSP’s output signal being intermittent. I think bypassing the Sabine is my next logical step but how to do it without messing something else up. Would you agree? Sorry for the length. Any suggestions appreciated.
Thanks, Billy.
response to email to Mr. Spense and I thank you so much for the input and helpful suggestion!
The single out of the mixer simply means your speaker system runs in mono. Pretty normal. The first 2 outputs are from a crossover in the NAV. One will be HF and the other LF. The third output likely feeds another room, possibly the foyer or a basement overflow room.
I suggest you post your pretty well written description in the church sound forum. Don't forget to have your display name be set to your real name.
In the forum, not only will you get more eyes on your problem, but others may learn from the dialog.
You use the term muting but do you simply mean the sound is silenced periodically?
How long does the sound go away and how often?
You have an install version of the NAV which is why the connector blocks.
I use a NAV480 and it has level indicators on the front for all inputs and outputs.
Look at them when the sound drops and see if it is an input or an output?
Good luck and see you on the forums.
Rob Spence
Lynx Audio Services
" We Get Live!"
I learned today that we have a "Gigrac" 1000st in our fellowship hall that is connected to our sound system. I was unaware of this and thought it was a separate system on its own. I'll bet that this is the elusive third connection. By the way, do the green "Phoenix" connectors unplug from the back of the NAV 360 before I do some damage or must I unscrew the leads from them?
Thanks for the help!
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Does the system mute at a certain time? Loud music etc?
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As mentioned, when the system mutes check and see what level meters
are showing any signal level. I the DSP input meter still shows signal your mixer is not the problem, if the output meters sill show signal level most likely the DSP is not the problem, though it maybe possible that the meters would show an output level and the actual outputs are dead/muted.
If the meters on the DSP all show signal level when the main system mutes do you have signal to the system in the fellowship hall?
When the system mutes check if you see any of the green signal
lights on the QSC amp are still blinking showing that the amp is getting audio signal.
Does the system start acting up at random times or only after it have been turned a while.
What does it take to make the system un-mute after it has muted or is it a fast in and out of mute at random times.
From your description of the speaker wiring it sounds like the speakers are passive so the DSP is more than likely providing high pass filtering, EQ and limiting, than again depending on the installer it maybe acting as no more than a line level split feeding the three amp inputs.
To bypass the dsp all you need to do is take a mic cable from the output on the mixer and connect it directly to the amps input.
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One possibilty and a simple check is that the M output is dropping out do to an internal intermittent connection.
Since L & R are unused I assume you are running mono. In that case, as long as all pans are centered, you should be able to run off L or R just like M so switch to one of those and use its master as the sytem master see if the problem continues.
You are headed the right way seeing that the problem continued with a different amp- just need to think through what you change to see what the problem follows.
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The system mutes totally at random, with and without instruments and or vocals, sometimes briefly and sometimes for an extended period. it has muted for as long as thirty-ish minutes on a couple of instances. I don't know if it is related but when it mutes I always attenuate the levels on the mixer because when it comes back on it is usually LOUD if I don't adjust it before.
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If things go as planed I am going to connect do the DSP this weekend and see if I can notice what is happening. From what I've been able to tell so far the three main speakers are all running full range as we have no subs and no outboard crossovers between the EQ or the DSP and the amps. The DBX EQ is strictly on the stage monitor circuit which as far as I can tell is not effected by the "muting" scenario. I think you may be correct with the line level splitter being the primary reason for the DSP. If I attenuate the L or R main slider it does change the overall volume level and texture of the sound. We do have all three (LRM) up near 0 in normal operation. Questions does "unity" equal "0" and should I found a switch somewhere on the mixer for stereo/mono output. I think you are saying unplug the "M" XLR and move it to "L" or "R" and see if the condition follows.
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I forgot to mention that when this muting happens I never lose the power lamps or cooling fans on either amp. Most of the time I do lose the signal lights on the house amp (sometimes they just get very dim)but never on the monitor amp and have yet to see a clip light on either amp. The only time I ever see a clip level on the mixer is once in a while when on our Pastors wireless channel as his mic is fairly sensitive and he projects well. We usually have his channel below 0 around 15 on the slider I think.
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One thing I didn't ask was where are you located? There are forum members in the darnnest places.
Sent from my iPad using Tapatalk HD
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I just Googled the 1850 manual. Page 19 addresses safe operating levels and cooling issues: ventilation/airflow.
Page 23 addresses the auto-muting brought on by excessive interior temperatures.
A good guess would be that something like clogged filters (have they EVER been cleaned?) or obstruction of the intake of cooling air or the exhausting of heated air has happened.
Check these issues. Cleaning the filters is simple. Insuring unrestricted air flow is likewise a simple matter. If the filters are obviously clogged from lack of the recommended periodic maintenance it might be advisable to have an electronics repairman remove the casing and blow any dust and dirt out of the interior.
As always, the first thing to do before WAGing is to RTBM.
Good luck.
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I just Googled the 1850 manual. Page 19 addresses safe operating levels and cooling issues: ventilation/airflow.
Page 23 addresses the auto-muting brought on by excessive interior temperatures.
I'm with Dick on this one.
Considering the timing and duration of the mute, overheated amps could be the issue.
Start there and work back.
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If you rule out heat protection in the amps I would look into your power. I've had sound equipment act up all weird like, only to find after an extensive fault searching session that the voltage in the wall outlet was only 70V... Plugging into a good outlet with 230V (I live in Europe, we have REAL power in our walls...) and the problems vanished.
Heating, hot water heaters, AC etc. could screw up your voltage if there's something wrong.
...but check the temp overload protection first.
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Is the Mixer or the Sabine unit on a UPS? Could there be a temporary power drop triggered by, say a coffee urn or other electrical device elsewhere in the building? Similar questions around the HVAC system. Does the muting occur whether the building is full of members during service or empty for rehearsals? Just raising a few other possibilities to look into..
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The system mutes totally at random, with and without instruments and or vocals, sometimes briefly and sometimes for an extended period. it has muted for as long as thirty-ish minutes on a couple of instances. I don't know if it is related but when it mutes I always attenuate the levels on the mixer because when it comes back on it is usually LOUD if I don't adjust it before.
So if your using the system and everything is working good up to the moment it cuts out if you touch nothing else at that point when the system comes back to life it is louder than it was before it cut out/muted?
Have you tried the ole fashioned tapping on the various pieces of equipment and moving cables around to see it that brings it back.
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If you rule out heat protection in the amps I would look into your power. I've had sound equipment act up all weird like, only to find after an extensive fault searching session that the voltage in the wall outlet was only 70V... Plugging into a good outlet with 230V (I live in Europe, we have REAL power in our walls...) and the problems vanished.
Heating, hot water heaters, AC etc. could screw up your voltage if there's something wrong.
...but check the temp overload protection first.
If you do find that you have extreme voltage swings, either below 110 volts or above 125 volts, the culprit may be a faulty connection on the neutral wire supplying an electrical breaker panel.
(The reason why is too complex for me to type on my phone.)
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It comes back at normal volume but it is abrupt and just seems loud phsycoacoustically. I have fiddled with cables and tickled sliders and buttons but the only thing that I have done that was probably a coincidence was banging on the audio rack at the bottom by the amps when I was on the floor trying to see if I could will the thing back into service.
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All of the circuits in our sound booth ( 2 Breakers) according to our breaker boxes are supposed to be separate from everything else. I guess I need to get one of those circuit chaser kits, Fox and Hound I think they call it, and do some verification on those outlets.
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It comes back at normal volume but it is abrupt and just seems loud phsycoacoustically. I have fiddled with cables and tickled sliders and buttons but the only thing that I have done that was probably a coincidence was banging on the audio rack at the bottom by the amps when I was on the floor trying to see if I could will the thing back into service.
Sometimes it a takes a good rap on a piece of equipment to get it to act up!
Did you have the muting problem today?
Try using either the left or right outputs on the board to feed the system, there is a recessed mono out source select switch on the right above the mono out fader, maybe try cycling that switch a few times.
The ribbon cable in the mixer may need to be re-seated.
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We do have a coffee urn in our foyer, although according to the labeling in our breaker boxes, our sound booth circuits are on a separate breaker. We do not have a UPS on our system. I may look into getting one once I figure out what is creating our issue and correct it if funds allow.
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Yes sir, it happened once today. It was about a minute long. I did lose signal lamps on the amp but saw no other indicators that lead me anywhere. I usually am working the power point instead of the sound board but saw no other indicators that suggested anything.
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You are welcome to elaborate in an email if you would prefer.
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Yes sir, it happened once today. It was about a minute long. I did lose signal lamps on the amp but saw no other indicators that lead me anywhere. I usually am working the power point instead of the sound board but saw no other indicators that suggested anything.
So did the meters on the DSP unit still show full active signal level?
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After church this morning I was able to connect to the DSP and view it with the software. WOW, this is neat. (newbie!!!) As one of you suggested, it appears that it is being used as a glorified line level splitter for the most part. Input 1 gain at "0" connected to outputs 1,2, and 3. Output 1 gain at 0, output 2 at 3.75, and output 3 at -21.75. There were 4 FBX points but I didn't alter anything except turning off the Input 2 output to output 2. There is nothing connected to input 2 so I figured it could not hurt anything. I did not notice any change. I ran the volume up pretty good for about an hour. This was after the service and all I had was a cd source I will try switching M to L and or R and see what happens.
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Next time it happens, forget the lights, bells and whistles and put your hand on the amp. If it's hot, you're in thermal protect.
All the info you've given and the signs point to thermal shut-down. Once you either confirm or rule this out then you can proceed further...if needed.
I think you'll find the amp is going into protect as described in the manual on the pages I linked.
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Next time it happens, forget the lights, bells and whistles and put your hand on the amp. If it's hot, you're in thermal protect.
All the info you've given and the signs point to thermal shut-down. Once you either confirm or rule this out then you can proceed further...if needed.
I think you'll find the amp is going into protect as described in the manual on the pages I linked.
That was my thought pattern when it happened on the original main amp, RMX1850HD. That is also why I removed it from the system and sent it in for a physical. I moved the 1450 into service on the FOH circuit and now am getting the same scenario. This is why I am now exploring the DSP. I figure sooner or later and can remove/eliminate the culprit. I just hope I don't have to figure out how to eliminate the mixer. I am doing all of this without a connection roadmap and am creating one as I go. The mixer has many connections!
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Clarksville Texas
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That was my thought pattern when it happened on the original main amp, RMX1850HD. That is also why I removed it from the system and sent it in for a physical. I moved the 1450 into service on the FOH circuit and now am getting the same scenario. This is why I am now exploring the DSP. I figure sooner or later and can remove/eliminate the culprit. I just hope I don't have to figure out how to eliminate the mixer. I am doing all of this without a connection roadmap and am creating one as I go. The mixer has many connections!
Bill...
There are several common scenarios for amps over-heating.
1. Lack of ventilation/cooling air, blocked exhaust.
2. Dirt and dust in the amp interior.
3. AC power issues, usually under-current.
4. Shorting speaker cable, poor connection on the output side.
5. Improper loading of the output. Possible causes include miscalculation of impedance matching due to amp run in bridge mode instead of stereo. Inadvertent bridging could also result in connection error with your speaker cables.
The fact that the situation clears itself up after a muted interval points squarely to the thermal issue. Amp heats up, goes into protect (mutes), cools below protect threshold, etc. QSC repair may well find no fault in
the amp if the protect feature is functioning for its intended purpose. This would indicate that something outside the amp itself is causing the overheating.
There is very little chance that the system processor is at fault. Highest probabilities are as above: power and/or cabling, load/mode, connections...you get the idea. Right now it seems like you're looking for a particular culprit when it may just as well be a configuration, connectivity or power issue.
One thing to consider: has anything in the building changed lately? Do any changes (even in the kitchen or physical plant) coincide with the onset of the "muting"?
Good luck.
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Bill...
There are several common scenarios for amps over-heating.
1. Lack of ventilation/cooling air, blocked exhaust.
2. Dirt and dust in the amp interior.
3. AC power issues, usually under-current.
4. Shorting speaker cable, poor connection on the output side.
5. Improper loading of the output. Possible causes include miscalculation of impedance matching due to amp run in bridge mode instead of stereo. Inadvertent bridging could also result in connection error with your speaker cables.
The fact that the situation clears itself up after a muted interval points squarely to the thermal issue. Amp heats up, goes into protect (mutes), cools below protect threshold, etc. QSC repair may well find no fault in
the amp if the protect feature is functioning for its intended purpose. This would indicate that something outside the amp itself is causing the overheating.
There is very little chance that the system processor is at fault. Highest probabilities are as above: power and/or cabling, load/mode, connections...you get the idea.
Good luck.
I agree completely with Dick. I have been lurking in the thread awaiting the outcome and all along was agreeing with amp protection. The fact you moved another amp and it is doing the same thing only adds another data point to support my theory.
First would be bad wiring or some other issue along that order. I would split the output with a set of y cables, hook up the original amp to a test speaker with a short length of known good wire. If the output in the mains goes away and you still have sound at the test rig you have now eliminated DSP and mixer.
The I would look in this order: 1 - Faulty speaker or wiring 2 - Issue with AC supply
Placing a UPS on an amplifier to correct a supply issue is not a correct option. That's just covering up the issue.
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First would be bad wiring or some other issue along that order. I would split the output with a set of y cables, hook up the original amp to a test speaker with a short length of known good wire. If the output in the mains goes away and you still have sound at the test rig you have now eliminated DSP and mixer.
The I would look in this order: 1 - Faulty speaker or wiring 2 - Issue with AC supply
Most of the time when a sound system is intermittent the problem turns out to be a cable.
Mac
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I had a service call at an install I did where they were loosing the high frequency ( tri-amped system). During walk in music it was kind of working, once the service started and the system was starting to hump a little the highs would start cutting in and out in an almost clock work like pattern. Someone had ran a drywall screw through the speaker line feeding the drivers on one side. Pulling the speaker lines off the amp and measuring the resistance of each found the problem line real quick, disconnecting it from the speaker proved it was somewhere in the speaker line real quick, checking the speaker cable from the amp out to the speakers not so quick.
Once your system starts muting does it go in and out of mute at some what regular intervals, that would be the amp over heating, cooling down, over heating, cooling down and again and again. That would also depend on how steady and hard the system is being driven.
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So did the meters on the DSP unit still show full active signal level?
Our DSP is a slave unit, 360-S, so I could not tell anything about indicators until I got logged into it after church. Sorry for delay. I have changed mixer outputs from M to L. I do seem to notice what I think is an overall reduction in output volume. All pans are centered. I have not been able yet to test in real session. Can anyone tell me if the green connectors on back of the Navigator unplug in case I decide to change some cables, which I am preparing for in the event that I still have this muting after the output change. Please correct me if I am wrong, but it seems to me that if the mixer is in mono, and the DSP has only the one input, should the volume not stay the same as the channels are summed? I'm not good yet at reading these block diagrams but it appears the L, R, and M all come from the same place. Maybe I am wrong, but I don't think it is a thermal protection issue. The second amp from the aux circuit, now on the FOH circuit, was not muting on the aux circuit. Is it possible that the "ribbon cable" for the L or R connect independently from the M? I am very intimidated about breaking open the mixer and getting it all reconnected properly. Thanks.
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This may not be your problem, but I did an install in a church that worked well UNTIL they decided to put surge protectors on all their gear. They were the cheap MOV plastic cubes. Their power amp started "muting" for about a minute and then worked for a fairly long period of time. It sometimes never muted and sometimes did it several times during a service. The customer became convinced it was the brand of power amp, so I gave them a 100% trade-in for another "more professional" brand. The new amp was about 2.5 X more money.
The same problem appeared. They ask for a refund (which I gave them) and they changed brands again. This time they paid 3.5 times as much for another very expensive unit from another vendor. You guessed it. I got another call for the same problem. I pulled all the cheap MOV surge protectors (they had then on everything and everywhere) and they had no more problems. They still wanted surge protection, but they didn't like the price for the "good" protection I suggested. I don't know what they ended up doing, but ditching the MOV's solved the muting problem.
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Our DSP is a slave unit, 360-S, so I could not tell anything about indicators until I got logged into it after church. Sorry for delay. I have changed mixer outputs from M to L. I do seem to notice what I think is an overall reduction in output volume. All pans are centered. I have not been able yet to test in real session. Can anyone tell me if the green connectors on back of the Navigator unplug in case I decide to change some cables, which I am preparing for in the event that I still have this muting after the output change. Please correct me if I am wrong, but it seems to me that if the mixer is in mono, and the DSP has only the one input, should the volume not stay the same as the channels are summed? I'm not good yet at reading these block diagrams but it appears the L, R, and M all come from the same place. Maybe I am wrong, but I don't think it is a thermal protection issue. The second amp from the aux circuit, now on the FOH circuit, was not muting on the aux circuit. Is it possible that the "ribbon cable" for the L or R connect independently from the M? I am very intimidated about breaking open the mixer and getting it all reconnected properly. Thanks.
The drop in level from the summed mono out to just one side of the stereo out is normal.
Before you start cracking open equipment you need to isolate the problem. I would go into the church on an off day with no other distractions, recreate as much as you can of a normal service with out a band, fire up some music through the system at the normal level of a service and wait and see if it acts up and after it acts up start narrowing it down by a piece at a time. An xlr cable from the mixer directly to the amp will be a quick way to bypass the DSP.
Just so we can all take a look post up some pictures of the back of your amp, a close up of the DIP switches on the back of the amp, the back of the DSP and the back of the mixer while you at it.
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The drop in level from the summed mono out to just one side of the stereo out is normal.
Before you start cracking open equipment you need to isolate the problem. I would go into the church on an off day with no other distractions, recreate as much as you can of a normal service with out a band, fire up some music through the system at the normal level of a service and wait and see if it acts up and after it acts up start narrowing it down by a piece at a time. An xlr cable from the mixer directly to the amp will be a quick way to bypass the DSP.
Just so we can all take a look post up some pictures of the back of your amp, a close up of the DIP switches on the back of the amp, the back of the DSP and the back of the mixer while you at it.
I still need to know if I will do any harm to any part of the system by turning the amp on with only one input connected as the amp is set for stereo operation on dip switches. And do green connectors, input and outputs on dsp, unplug?
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I still need to know if I will do any harm to any part of the system by turning the amp on with only one input connected as the amp is set for stereo operation on dip switches. And do green connectors, input and outputs on dsp, unplug?
It will do no harm, and yes, they do unplug.
Mac
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I don't think it's the amp(s). You've tried both, they've been sent in to QSC. You said sound goes out for minutes.
Can you check the DIP switch settings on the amp and post it here? Let's make sure the amps are indeed stereo and not bridged.
Do you have (or can borrow) another mixer that you can do an A/B/A with? Just to rule out the mixer.
The Nav 360 is an old piece (I have one that's over 10 years old and it's been freezing up on powerup.) It may be possible the internal power supply is on the fritz. Had that happen to me on one of our GRQs.
Since you have an install version with no lights/display on the front panel, it may not be obvious if the 360 is shutting down, locking up, etc.
As a test, can you take the 360 out of the loop? Set the high pass filter on the amp to 50Hz to help protect your speakers.
John R.
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I don't think it's the amp(s). You've tried both, they've been sent in to QSC. You said sound goes out for minutes.
Can you check the DIP switch settings on the amp and post it here? Let's make sure the amps are indeed stereo and not bridged.
Do you have (or can borrow) another mixer that you can do an A/B/A with? Just to rule out the mixer.
The Nav 360 is an old piece (I have one that's over 10 years old and it's been freezing up on powerup.) It may be possible the internal power supply is on the fritz. Had that happen to me on one of our GRQs.
Since you have an install version with no lights/display on the front panel, it may not be obvious if the 360 is shutting down, locking up, etc.
As a test, can you take the 360 out of the loop? Set the high pass filter on the amp to 50Hz to help protect your speakers.
John R.
Not being a tech I am not sure what is meant by A/B/A and I went through the DIP swirtch settings with QSC who confirmed they were correct. Both amps set the same but I will attempt to get some pics maybe tonight in case I missed something. Thank you all for helping me work through this. It is very much appreciated and you are all in my prayers.
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This may not be your problem, but I did an install in a church that worked well UNTIL they decided to put surge protectors on all their gear. They were the cheap MOV plastic cubes. Their power amp started "muting" for about a minute and then worked for a fairly long period of time. It sometimes never muted and sometimes did it several times during a service. The customer became convinced it was the brand of power amp, so I gave them a 100% trade-in for another "more professional" brand. The new amp was about 2.5 X more money.
The same problem appeared. They ask for a refund (which I gave them) and they changed brands again. This time they paid 3.5 times as much for another very expensive unit from another vendor. You guessed it. I got another call for the same problem. I pulled all the cheap MOV surge protectors (they had then on everything and everywhere) and they had no more problems. They still wanted surge protection, but they didn't like the price for the "good" protection I suggested. I don't know what they ended up doing, but ditching the MOV's solved the muting problem.
Our system has nothing other than our sequencer and a conditioner which btw is plugged into an unswitched outlet on the sequencer. Does that sound backwards should it matter?
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Our system has nothing other than our sequencer and a conditioner which btw is plugged into an unswitched outlet on the sequencer. Does that sound backwards should it matter?
Really getting in the weeds here IMHO. Please see my suggestion. Any speaker, even from home will do.
Isolate off the wiring.
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Not being a tech I am not sure what is meant by A/B/A and I went through the DIP swirtch settings with QSC who confirmed they were correct. Both amps set the same but I will attempt to get some pics maybe tonight in case I missed something. Thank you all for helping me work through this. It is very much appreciated and you are all in my prayers.
ABA just means compare one (A) to another (B) and then back to the first to make sure nothing changed while switching between.
For a mixer test, a simple one will do just to feed music into the system. Just a couple of inputs.
To be clear, amps these days don't care if there are inputs or outputs connected.
Sent from my iPad using Tapatalk HD
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Scott's suggestion is very good. This is Troubleshooting 101- divide and conquer-you have a reasonably simple system:
Mixer- DSP - amp - speakers
His suggestion will take a little effort, but will isolate to issue to one half- then you find a way to narrow it down. You will spend a lot of time trying to find a silver bullet far better to have a method.
The power conditioner/sequencer are not mission critical and could easily be eliminated temporarily-but that is not the first place I'd look.
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Really getting in the weeds here IMHO. Please see my suggestion. Any speaker, even from home will do.
Isolate off the wiring.
Thanks for the suggestion. I will try to find a speaker that I can use. After moving the mixer output from M to L, and being able to see the lights of the DSP controls, I turned on the system tonight and lo and behold, it muted again. This time I was able to see the DSP level indicators on both the input and outputs freeze at around -20. So I guess my next two tasks are to buy some new XLR cables as we have no spares, so I can bypass the DSP, and to find a test speaker. I will update later and thanks again. Oh, I did feel of the amplifier for temperature with my hand and it felt like it always does, barely warmer than when it is off. We have plenty of air flow clearance around our audio rack and I can feel the fans blowing very well. I'll use my thermocouple and meter next time. The dip switches on both amps are as follows. Numbers 2 and 9 are on the right, and all of the rest are on the left.
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DIP switches OK, although I would put only 1, 3, 8, 10 to the right (clip limiters on, high pass filter off -- you have a DSP that can do a better job.)
John R.
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Thanks for the suggestion. I will try to find a speaker that I can use. After moving the mixer output from M to L, and being able to see the lights of the DSP controls, I turned on the system tonight and lo and behold, it muted again. This time I was able to see the DSP level indicators on both the input and outputs freeze at around -20. So I guess my next two tasks are to buy some new XLR cables as we have no spares, so I can bypass the DSP, and to find a test speaker. I will update later and thanks again. Oh, I did feel of the amplifier for temperature with my hand and it felt like it always does, barely warmer than when it is off. We have plenty of air flow clearance around our audio rack and I can feel the fans blowing very well. I'll use my thermocouple and meter next time. The dip switches on both amps are as follows. Numbers 2 and 9 are on the right, and all of the rest are on the left.
That's a new data point. If the output meter freezes it could me the DSP.
So if I were you I would get a DI or whatever you can cobble together and drive the amp direct with something. If it doesn't go into protect you are not down to console or DSP.
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That's a new data point. If the output meter freezes it could be the DSP.
What is the possibility of a DC voltage feeding the input of the DSP causing the meters to to freeze (he said it was both the input and output meters)? Being DC, it wouldn't exhibit a (loud) hum, and if it's a constant voltage, it should present as silence.
I don't know -- educate me.
Then again, that shouldn't freeze the output meters.
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What is the possibility of a DC voltage feeding the input of the DSP causing the meters to to freeze (he said it was both the input and output meters)? Being DC, it wouldn't exhibit a (loud) hum, and if it's a constant voltage, it should present as silence.
I don't know -- educate me.
Then again, that shouldn't freeze the output meters.
I think that possibility is quite low. The digital high pass filter present in just about all A/D converter chips is almost always enabled to get rid of DC for audio bandwidth applications. A/D inputs are usually calibrated at power-up and even during run-time in some designs to compensate for reference voltage stability and thus DC offset. In pro applications the A/D converter is run in differential mode. Finally, the DSP chip will operate on the data from the A/D converter to remove anything not in the pass band (i.e. 20Hz - 20KHz) - BEFORE any kind of DSP operations such as EQ.
In general, DC offset at the input of an A/D converter is not desirable because it decreases the S/N ratio of the system. The A/D converter has a maximum analog input voltage (e.g. +5V), and in pro audio applications, this max input is usually HALF because the converter is run in differential mode. So you don't really want DC to get in there. On top of that, most A/D converters today are delta-sigma type. where DC can cause the modulator to just outputs continuous stream of 1's, causing the digital filter stage to clip.
John R.
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I think that possibility is quite low. The digital high pass filter present in just about all A/D converter chips is almost always enabled to get rid of DC for audio bandwidth applications. A/D inputs are usually calibrated at power-up and even during run-time in some designs to compensate for reference voltage stability and thus DC offset. In pro applications the A/D converter is run in differential mode. Finally, the DSP chip will operate on the data from the A/D converter to remove anything not in the pass band (i.e. 20Hz - 20KHz) - BEFORE any kind of DSP operations such as EQ.
In general, DC offset at the input of an A/D converter is not desirable because it decreases the S/N ratio of the system. The A/D converter has a maximum analog input voltage (e.g. +5V), and in pro audio applications, this max input is usually HALF because the converter is run in differential mode. So you don't really want DC to get in there. On top of that, most A/D converters today are delta-sigma type. where DC can cause the modulator to just outputs continuous stream of 1's, causing the digital filter stage to clip.
John R.
Why would they not put a DC blocking capacitor on the input? That's engineering 101
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Why would they not put a DC blocking capacitor on the input? That's engineering 101
Rise time. I've seen it both ways.
John R.
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It's sounding like the DSP maybe the issue.
To test bypassing the DSP just borrow a couple XLR cables from some mics on the stage, but you need to have extra XLR mic cables on hand anyway, buy an arm load of good ones, not ebay specials for $2 each!
As for the switch settings on the QSC amp, I would have 1 & 10 to the right to turn on clip limiting.
No disrespect here are at all, you've done a great job at communicating with us your problem, the trouble shooting your doing and of course stepping up to work at taking care of an ongoing problem at your church.
I think your at the point where bringing in some professional outside help to get this taken care of and your system back and running reliably in short order.
Even after finding the problem something is going to need to be repaired, replaced, rewired, reprogrammed or all of the above.
With professional outside help that would all go a lot faster and if needed they most likely would have a loaner piece of equipment to get you going while either a replacement was ordered or the defective piece was repaired.
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It's sounding like the DSP maybe the issue.
To test bypassing the DSP just borrow a couple XLR cables from some mics on the stage, but you need to have extra XLR mic cables on hand anyway, buy an arm load of good ones, not ebay specials for $2 each!
As for the switch settings on the QSC amp, I would have 1 & 10 to the right to turn on clip limiting.
No disrespect here are at all, you've done a great job at communicating with us your problem, the trouble shooting your doing and of course stepping up to work at taking care of an ongoing problem at your church.
I think your at the point where bringing in some professional outside help to get this taken care of and your system back and running reliably in short order.
Even after finding the problem something is going to need to be repaired, replaced, rewired, reprogrammed or all of the above.
With professional outside help that would all go a lot faster and if needed they most likely would have a loaner piece of equipment to get you going while either a replacement was ordered or the defective piece was repaired
I put two new xlr cables from l and r on mixer (m disconnected) into amp inputs, bottomed out all faders and gains, put in a cd with some descent dynamics, slowly dialed in the gains, brought faders up to 0, dialed the amp gains up to a comfortably moderate volume and listened for several hours Saturday with no muting. No muting in today's service either. I believe it may be time to research a new DSP. Thanks again for all the suggestions and encouragement.
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That was my gut feeling early on!
As for a DSP look at the DBX 260 or the newer DBX Venue 360.
Both are good DSP's , easy to program. The 360 will let up set it up via an iPad or Android app and make system adjustments from anywhere in the room. You can download the apps and play with them in the offline mode.
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I put two new xlr cables from l and r on mixer (m disconnected) into amp inputs, bottomed out all faders and gains, put in a cd with some descent dynamics, slowly dialed in the gains, brought faders up to 0, dialed the amp gains up to a comfortably moderate volume and listened for several hours Saturday with no muting. No muting in today's service either. I believe it may be time to research a new DSP. Thanks again for all the suggestions and encouragement.
Before you 86 the DSP, check the cables you removed. No stone unturned and all that.
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That was my gut feeling early on!
As for a DSP look at the DBX 260 or the newer DBX Venue 360.
Both are good DSP's , easy to program. The 360 will let up set it up via an iPad or Android app and make system adjustments from anywhere in the room. You can download the apps and play with them in the offline mode.
Having used the Driverack 260 for many years as my main DSP, I can't recommend it. There are others (e.g. Xilica) that sound much better.
John R.
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One more thing before replacing geat:
Clean the connections...ALL connections.
The system looks to have been in place and undisturbed for a number of years. Any XLR's, 1/4" connectors, etc, can oxidize and suffer diminished connectivity. Some De-oxit, small nylon brushes and a .25 caliber bore cleaning brush (1/4" jacks) is all you need.
An oxidized connector could well yield the problem you describe as muting.
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That was my gut feeling early on!
As for a DSP look at the DBX 260 or the newer DBX Venue 360.
Both are good DSP's , easy to program. The 360 will let up set it up via an iPad or Android app and make system adjustments from anywhere in the room. You can download the apps and play with them in the offline mode.
We currently have three inputs available on our dsp. We were only using one on foh circuit. We have a graphic eq on our monitor circuit. Would it be over kill to run the monitor circuit through a dsp as well and use the other eq elsewhere. Running two amps and the Gigrac from 3 outputs, would it be smart of me to look for more inputs incase we hopefully ad some sub channels in the future?
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ABA just means compare one (A) to another (B) and then back to the first to make sure nothing changed while switching between.
For a mixer test, a simple one will do just to feed music into the system. Just a couple of inputs.
To be clear, amps these days don't care if there are inputs or outputs connected.
Sent from my iPad using Tapatalk HD
any idea what a qsc core 110f would cost?
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any idea what a qsc core 110f would cost?
The Core 110f runs $2,999.00 MSRP.
Have you had QSYS Training or would you be hiring this out to be changed and programmed?
QSYS, Soundweb London, BiAmp, etc. are all good DSP systems, each with their own pro's and con's. Each requires a good deal of training in order to implement effectively. Each of the manufacturers has good online training classes that are a great starting point but, as with most things technological, that is the starting point.
Lee
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How did you pick the QSC Core series, those are big boy DSP's as are the other models Lee mentioned with lots of programing and control capabilities that I don't think you need to pay for and not use.
The DBX360 I mentioned is a three in / six out DSP. With that you could use an input for mains, an input for monitors and an input for aux fed subs when you add subs to your system.
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How did you pick the QSC Core series, those are big boy DSP's as are the other models Lee mentioned with lots of programing and control capabilities that I don't think you need to pay for and not use.
The DBX360 I mentioned is a three in / six out DSP. With that you could use an input for mains, an input for monitors and an input for aux fed subs when you add subs to your system.
They were just items that came up on some random searches I was doing in case we had to replace our dsp to get our functionality back. I have also had some extremely good conversations with QSC tech support, we have two of their amps, ( along with folks on this forum) about our amplifiers when I originally dove into this quest.
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They were just items that came up on some random searches I was doing in case we had to replace our dsp to get our functionality back. I have also had some extremely good conversations with QSC tech support, we have two of their amps, ( along with folks on this forum) about our amplifiers when I originally dove into this quest.
What is the DSP actually doing? I thought it seemed earlier in this thread that is was basically being used as a distribution amp. That's a pretty expensive DA. If you have someone who can come in and set up the DSP and optimize your system there may be a reason to spend money on a new DSP, but to use it as a DA, not so much.
Mac
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What is the DSP actually doing? I thought it seemed earlier in this thread that is was basically being used as a distribution amp. That's a pretty expensive DA. If you have someone who can come in and set up the DSP and optimize your system there may be a reason to spend money on a new DSP, but to use it as a DA, not so much.
Mac
To take that further, as it sounded your DSP was set up to do nothing more than act as DA. If indeed that's all that is was doing having a properly set up and optimized DSP for your system may very well bring your system to level it has never operated at before.
You don't need a $3000 DSP to do basic EQ, Limiting and bandpass filtering.
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What is the DSP actually doing? I thought it seemed earlier in this thread that is was basically being used as a distribution amp. That's a pretty expensive DA. If you have someone who can come in and set up the DSP and optimize your system there may be a reason to spend money on a new DSP, but to use it as a DA, not so much.
Mac
As I understand the hook up and software routings, it was basically being used as a line level splitter, ( is that what you mean by DA?) It did have four feedback notches that I could see but no x-over, time delay or EQ settings that I could tell. But now that it seems to be freezing up, I am going to check the firmware version and possibly update it to see if it will cure it. This being the case, when we get our FOH amp back, I am considering connecting it to our EQ (DBX 231) and running it in stereo. Then setting our monitor amp for parallel input and feeding our Gigrac from input two. I was just exploring some ideas about replacing the unit and if so with what. As I am new to anything other than typical consumer audio stuff, I am on a steep learning curve and trying to become informed before dropping a bundle of money on something we don't need. I think we can get away without it at least for a while until I can make some educated decisions about our needs and how they align with our budget, to say nothing of user friendliness as there are several of us that cover the sound board, of which I am the newest. Thank you ALL again for your input.
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Well I have had some professionals from a company in DFW come see us and our system to give some proposals on a route forward. Looking at our I/o meters on our dsp when the sound is running, we have some "blips" that go from the top of the green signal level up to the top of the scale, and yes totally random. I have not beeb able to get a pic of it happening when the system "mutes" yet but I have a short iPhone video of it in a live setting that I am trying to figure out how to post here so I can get some feedback on them. I have asked them to submit a quote to me to have one of their tech's come in with an o-scope to determine if it (blips) is being caused by the mixer or if it is isolated to the dsp. Hopefully the later then some proposed options to replace, tune, train, and finally move forward. Any comments welcome, just felt like I owed an update to those who have graciously given their valuable time and advise to our cause. Thank you one and all.
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Well I have had some professionals from a company in DFW come see us and our system to give some proposals on a route forward. Looking at our I/o meters on our dsp when the sound is running, we have some "blips" that go from the top of the green signal level up to the top of the scale, and yes totally random. I have not beeb able to get a pic of it happening when the system "mutes" yet but I have a short iPhone video of it in a live setting that I am trying to figure out how to post here so I can get some feedback on them. I have asked them to submit a quote to me to have one of their tech's come in with an o-scope to determine if it (blips) is being caused by the mixer or if it is isolated to the dsp. Hopefully the later then some proposed options to replace, tune, train, and finally move forward. Any comments welcome, just felt like I owed an update to those who have graciously given their valuable time and advise to our cause. Thank you one and all.
You don't need any scope to see / hear where the blipping is coming from, Take a small powered speaker and plug into the board and listen and wait then plug it into an output on the DSP and listen and wait!
You could split the signal from the board, one side of the split feeds the system and the other feeds the powered speaker, connect the second powered speaker to one of the main DSP outputs. Wait and listen to see what speaker the blipping comes from and there will be your answer. You could do the same test with a stereo headphone amp and a set of headphones.
A battery powered headphone amp and a set of headphones are a great piece of low tech trouble shooting equipment.
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You don't need any scope to see / hear where the blipping is coming from, Take a small powered speaker and plug into the board and listen and wait then plug it into an output on the DSP and listen and wait!
You could split the signal from the board, one side of the split feeds the system and the other feeds the powered speaker, connect the second powered speaker to one of the main DSP outputs. Wait and listen to see what speaker the blipping comes from and there will be your answer. You could do the same test with a stereo headphone amp and a set of headphones.
A battery powered headphone amp and a set of headphones are a great piece of low tech trouble shooting equipment.
I should have mentioned that the blips are not audible that I can find, just visible on the input / output led's of the dsp, but if I can coble something together, I may try the powered speaker test anyway. Thanks.
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I should have mentioned that the blips are not audible that I can find, just visible on the input / output led's of the dsp, but if I can coble something together, I may try the powered speaker test anyway. Thanks.
In that case just disconnect the inputs and outputs from the DSP and then start watching it, if no blips, connect the inputs back up to the DSP, start watching, don't blink, if still no blips connect the outputs back to the DSP, start watching.
Have ever notice the meters on the board doing the blip dance?
Surprised your not hearing anything at the time of the blip, a click, pop, tick whatever, even if it's a dc pulse I would guess some artifact of it would make it through the high pass filters on the other hand some ultrasonic blip maybe able to go undetected.
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So the DSP has been replaced with a mono 1/3 octave EQ from our old sound system and I am about to try to use the noise generator to get the feedback out. My question is do I first work on the monitor circuits without the mains, or the mains without the monitors, or do I do it all at the same time? Our monitors are on aux's 1 and 2 and our mains are on "M" out of the mixer through the EQ and using parallel input on the amp with stereo out. Up to this point I can not get any volume on our choir without getting feedback.
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So the DSP has been replaced with a mono 1/3 octave EQ from our old sound system and I am about to try to use the noise generator to get the feedback out. My question is do I first work on the monitor circuits without the mains, or the mains without the monitors, or do I do it all at the same time? Our monitors are on aux's 1 and 2 and our mains are on "M" out of the mixer through the EQ and using parallel input on the amp with stereo out. Up to this point I can not get any volume on our choir without getting feedback.
If you only have a mono EQ you can't EQ both mains and monitors.
Choir should not typically be fed back to itself in the monitors as that leads to problems such as feedback, among other things.
Was your DSP providing crossover functions?
Was or providing limiting?
Lee
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If you only have a mono EQ you can't EQ both mains and monitors.
Choir should not typically be fed back to itself in the monitors as that leads to problems such as feedback, among other things.
Was your DSP providing crossover functions?
Was or providing limiting?
Lee
Maybe I should have restated that the two monitor circuits from aux 1/2 go through a DBX 231 EQ. They never went through the DSP. The DSP had no crossover or eq or delay or compressor/limiter settings. It was strictly being used as a line level splitter and feedback eliminator. I have engaged the 50 Hz filter on both amps and on the DBX. Also the PEQ on our mixer ( A/H GL 2400-32 ) is controlling our aux 1/2 simultaneously with the mains. Is that the norm and does it mean I need to change 1 to 32 internal jumpers to have independent control? I was told by A/H that aux 1/2 was pre eq, 3/4 were selectable and 5/6 were post but the pre/post switch seems to be global for 1/2. We have nothing going out on 3-6. I am seriously considering installing a BSS BLU-100 or 160 or maybe a Driverack 4820 if I cant tame this system with eq's.
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I'm 97% certain you do not need a DSP to the likes of a BSS BLU series or a DBX 4820 for your system.
Don't take this wrong, you have given this a great effort over the past months and I'm sure it's been a learning experience but I think it may be time to bring some pro help to get your church's system back up and fully operational.
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I'm 97% certain you do not need a DSP to the likes of a BSS BLU series or a DBX 4820 for your system.
Don't take this wrong, you have given this a great effort over the past months and I'm sure it's been a learning experience but I think it may be time to bring some pro help to get your church's system back up and fully operational.
The professionals I brought in from DFW gave us a proposal for a BLU 100, install, tuning our room/system and some training at a little over $5k. I do like the 12/8 I/O setup of the blu100 and flexibility of the 160, I even like the 4/8 I/O of the 4820 but I am suffering a bit on the software for the BSS. Steep learning curve, but if I can figure it out it just may be a solid option as most all of the other dps's I look at are only 2 channel in and they apply configurations to paired outputs. If you have any other suggestions I am open to them.
Thanks.
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The professionals I brought in from DFW gave us a proposal for a BLU 100, install, tuning our room/system and some training at a little over $5k. I do like the 12/8 I/O setup of the blu100 and flexibility of the 160, I even like the 4/8 I/O of the 4820 but I am suffering a bit on the software for the BSS. Steep learning curve, but if I can figure it out it just may be a solid option as most all of the other dps's I look at are only 2 channel in and they apply configurations to paired outputs. If you have any other suggestions I am open to them.
Thanks.
This is much more than an issue of learning the software. There is the entire aspect of how to properly setup the DSP for what you need it to accomplish. This takes someone with experience in order to get a job well done.
That said, I certainly encourage you to learn the software but you also have to learn system design on the electronic level, not just in plugging components together. There are reasons to place compressors both before and after EQ blocks, all depending on what you are trying to achieve. There are reasons to use limiters inside of a crossover or reasons to use them stand alone at another point in the signal chain, etc., etc.
Hire someone who is willing to let you watch and learn but understand that if you change programming and it causes a problem that they need to return to correct, it will cost a service call.
Lee
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So I guess I go back to my question of how to properly eq the system, start on monitors or house or all at the same time. Any tips appreciated. We don't have a mega budget to do this on so I am still going to at least try to conquer the situation as best I can.
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Well a new venu360 is on the way. Could anyone point me to where I might figure out where to position the rta mic as our speakers are about 17 feet in the air, all three mounted together in sort of a fan or splayed arrangement.
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Well a new venu360 is on the way. Could anyone point me to where I might figure out where to position the rta mic as our speakers are about 17 feet in the air, all three mounted together in sort of a fan or splayed arrangement.
Leave it in the box (the RTA) mic. The money you spent on it should have gone towards a professional to set it up.
With all due respect we can give you tips but when you start asking about tuning monitors and mains at the same time (not even sure how the processor effects the monitors) it demonstrates you don't have the experience to do the job. It's not a following instructions. It takes years of experience to properly gain stage and tune a system.
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Leave it in the box (the RTA) mic. The money you spent on it should have gone towards a professional to set it up.
With all due respect we can give you tips but when you start asking about tuning monitors and mains at the same time (not even sure how the processor effects the monitors) it demonstrates you don't have the experience to do the job. It's not a following instructions. It takes years of experience to properly gain stage and tune a system.
I was planning to run aux 1 to input 1, aux 2 to input 2, and "M" to input three. this would eliminate both external geq's which would clear up my guessing at a correct input trim on the old peavey that has no meter or lights to tell me where my gain level is. In addition it would free up some slots so I can put our wireless mic units on a shelf in the rack and clean up some wiring. Thanks for the criticism though. I do realize I am not a pro at this. I also realize our church is on a very small budget and that no one objected when I volunteered to try to tackle the situation. I also know that Christ is the only deity deserving of the name AWESOME. Considering what he did for all mankind if they would just receive it, I figure serving Him by serving my church deserves every effort I have. God Bless you all and thanks for your help!
Billy.
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I was planning to run aux 1 to input 1, aux 2 to input 2, and "M" to input three. this would eliminate both external geq's which would clear up my guessing at a correct input trim on the old peavey that has no meter or lights to tell me where my gain level is. In addition it would free up some slots so I can put our wireless mic units on a shelf in the rack and clean up some wiring. Thanks for the criticism though. I do realize I am not a pro at this. I also realize our church is on a very small budget and that no one objected when I volunteered to try to tackle the situation. I also know that Christ is the only deity deserving of the name AWESOME. Considering what he did for all mankind if they would just receive it, I figure serving Him by serving my church deserves every effort I have. God Bless you all and thanks for your help!
Billy.
Billy spare the speech, I have been doing HOW audio since 1976 and every bit of politics and budgeting that can be imagined. I don't volunteer where I worship BTW.
Anyway, so you mention tuning the mains, if you are using the controller to process three monitor sends then how are the mains involved?
This isn't a personal criticism but a comment based on the reality that a pro could come in and achieve the desired results in short order. For you to learn at the church's expense is not good stewardship. There is a great article on why volunteers should not be in charge of purchasing decisions.
I am sure that your works are very much appreciated, this is not personal nor emotional. It's fact based. If you don't have the hard skills you are not doing any favors. The money you wasted on the measurement mic is a testament to that. A pro would have had his own mic and auto EQ is mostly a waste of time.
You rarely see volunteer plumbers or HVAC folks at a church but for some reason when it comes to tech it's Katy bar the doors. That's why the network, phone system, audio and lights are such a disaster at many facilities.
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You rarely see volunteer plumbers or HVAC folks at a church but for some reason when it comes to tech it's Kary bar the doors. That's why the network, phone system, audio and lights are such a disaster at many facilities.
When you do see volunteer plumbers/HVAC, even if they do the work professionally in their day jobs, they often take shortcuts because they know they can get away with it, because they want to get out of there quickly since they aren't being paid. (Often subconsciously.)
When you pay them through their company's regular billing process and have the proper inspections where applicable, things might cost more in the short term but in the long term it is cheaper because it's done correctly the first time so repair costs are lower.
That's part of the reason why I never do volunteer work that's the same as my day job. Running it through my company keeps me honest and ensures the customer gets the best possible product/service, and provides the customer a recourse if I screw up.
Just a general observation. Not criticizing anybody in particular.