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Sound Reinforcement - Forums for Live Sound Professionals - Your Displayed Name Must Be Your Real Full Name To Post In The Live Sound Forums => SR Forum Archives => LAB Lounge FUD Forum Archive => Topic started by: Haig Tellalian on July 19, 2010, 11:43:43 am

Title: Monitor dB Drop and Popping Noise
Post by: Haig Tellalian on July 19, 2010, 11:43:43 am
The dB output of our monitors would drop and we would get loud popping sounds when we would attempt to boost the output.  It was such a problem that we abandoned the monitors and used just the mains for the show.  Any ideas what could have happened?


OUR SETUP
PA: Yamaha emx512sc
Main Speakers: Two Yamaha S115V
Power Conditioner: Furman PL Plus Series II
Monitors: Three Behringer B212A Powered
19 Channel Snake
Inputs:
Three SM58
Two SM57
One Acoustic Guitar>Direct Box
Two Condenser Mics for Drum Kit with Separate Phantom Power

All was plugged into power conditioner except for Phantom Power Box.

We were using two household outlets, one for the power conditioner and the other was for the guitar and bass amps.

Thanks in advance for any help.
Title: Re: Monitor dB Drop and Popping Noise
Post by: Silas Pradetto on July 19, 2010, 11:46:26 am
Two outlets doesn't mean two circuits, and in your situation it probably wouldn't matter anyway.

I'm guessing your (low quality) powered monitors were overheating or limiting, or if they're lacking limiting, possibly exploding due to being overdriven.

There is a point all speakers reach where they just won't get any louder. For some speakers, that point is not loud enough to be much use to anyone.
Title: Re: Monitor dB Drop and Popping Noise
Post by: Tim McCulloch on July 19, 2010, 12:48:53 pm
What signals were being sent to the monitors?

The popping sound could happen for a couple of different reasons, but if you were just turning up the sends I'd say that over-excursion of the LF speaker is a likely culprit.  They were "bottoming out" when the voice coil former was hitting the back plate of the pole piece.

The reduction in level was probably the protection circuit kicking in or the internal amp was overheating.

Are these new, as in you've not used them in this situation/band/venue/music style before or is this a new problem with gear you've been using for a while?
Title: Re: Monitor dB Drop and Popping Noise
Post by: Haig Tellalian on July 19, 2010, 01:36:52 pm
Tim and Silas, thanks fo the feedback.

Tim, here are the answers to your questions...

1. Signals send to monitors (4 voice, 1 acoustic guitar)
2. Monitors two years old, we gig 4-6 times a year at different venues.  We've monitored all this before at other venues, including this same venue last year, except with 3 voice and 1 acoustic guitar.
Title: Re: Monitor dB Drop and Popping Noise
Post by: Tim McCulloch on July 19, 2010, 01:38:43 pm
If the monitors have been previously satisfactory, what has changed?
Title: Re: Monitor dB Drop and Popping Noise
Post by: Haig Tellalian on July 22, 2010, 05:28:36 pm
Hi Tim,
I noticed something else.  At the gig, the power level hovered at 110 the whole time.  I usually see power at 120v.  Could that have contributed to my issue?
Haig
Title: Re: Monitor dB Drop and Popping Noise
Post by: Silas Pradetto on July 22, 2010, 05:30:55 pm
Haig Tellalian wrote on Thu, 22 July 2010 17:28

Hi Tim,
I noticed something else.  At the gig, the power level hovered at 110 the whole time.  I usually see power at 120v.  Could that have contributed to my issue?
Haig


If it didn't dip below 110 then that wouldn't have been an issue.
Title: Re: Monitor dB Drop and Popping Noise
Post by: Brian Jojade on July 22, 2010, 06:02:14 pm
Silas Pradetto wrote on Thu, 22 July 2010 16:30

Haig Tellalian wrote on Thu, 22 July 2010 17:28

Hi Tim,
I noticed something else.  At the gig, the power level hovered at 110 the whole time.  I usually see power at 120v.  Could that have contributed to my issue?
Haig


If it didn't dip below 110 then that wouldn't have been an issue.


I would disagree with that.  Without knowing the gear in question, the difference in available power at 120 volts may be quite noticeable at 110 volts.  High end gear usually would be o.k, but B* speakers aren't necessarily known for their robust behavior in rough environments.  The 110 volts may have been dipping on your bass beats starving the speakers of the power they wanted, thus resulting in dismal performance.
Title: Re: Monitor dB Drop and Popping Noise
Post by: Tim McCulloch on July 22, 2010, 06:18:20 pm
Haig Tellalian wrote on Thu, 22 July 2010 16:28

Hi Tim,
I noticed something else.  At the gig, the power level hovered at 110 the whole time.  I usually see power at 120v.  Could that have contributed to my issue?
Haig


Contributed?  Possibly, but it's hard to say.  Generally I'd agree with Silas that it *shouldn't* be of consequence, but diagnosing via internet isn't a precise science.

Your best bet will be to try an recreate the failure in a controlled (non-gig) environment.

There doesn't seem to be an over-abundance of LF content, but I don't have any experience with your band or gear.

If it has all worked without issues before, you need to figure out what changes, settings, venue, power cords, ambient temperature... anything that is exceptional to the normal, expected results you've received.

Have fun, good luck.

Tim Mc
Title: Re: Monitor dB Drop and Popping Noise
Post by: john sanders on July 22, 2010, 07:03:39 pm
From my experience not enough voltage.
Title: Re: Monitor dB Drop and Popping Noise
Post by: Bennett Prescott on July 22, 2010, 11:13:37 pm
What console are you using, and how old is it?
Title: Re: Monitor dB Drop and Popping Noise
Post by: Haig Tellalian on July 23, 2010, 10:17:42 am
Yamaha emx512sc - 3 years old

Thanks everyone for the responses.