LED Par cans cause buzz on some acoustic pickups

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Brian jojade

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Jan 15, 2011
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Wausau, WI
www.happymacshop.com
O.K, so this is a new one for me, and I'm looking for suggestions. Working in a smaller venue that is using American DJ LED Pro 64 par cans for lighting. They are about 10 feet up and about 12 feet from the front of the stage. Nothing too fancy, and they do the job well. Lots of different acts perform here, and usually things are just fine. However, with a few of them, the acoustic pickups in the instruments will pick up a buzz from the lights.

What is really interesting is that this seems to be an induced buzz, and no amount of filtering of the power will fix the problem. If the performer faces the front of the stage, there is buzz. If they turn away from the lights, the buzz goes away. I have gone as far as put the instruments on wireless body packs, and thhe buzz still happens. It's not your typical 60 hz hum. Using a midrange notch filter, we can sometimes limit the issue, but that's not an ideal solution.

So, I am looking for a solution to this problem, hopefully that does not involve replacing of the lights. Any ideas?
 
Re: LED Par cans cause buzz on some acoustic pickups

Get rid of single coils? LOL! I'd guess that 60 - 70% of bands have a guitarist or bass player with single coils, maybe more.
I understand the wish for cleaner sound, but not many guitarists will give up what they feel is superior tone to convenience a sound man
 
Re: LED Par cans cause buzz on some acoustic pickups

Steve Hurt said:
Get rid of single coils? LOL! I'd guess that 60 - 70% of bands have a guitarist or bass player with single coils, maybe more.
I understand the wish for cleaner sound, but not many guitarists will give up what they feel is superior tone to convenience a sound man
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The best guitarists I know have tools to have their guitar sound not ruined by the interference du jour. This isn't necessarily convenience of the sound man - it's partnering with the sound man to have the show not suck. We need to find tools that work good (maybe the American DJ cans need to go in this case), but if the band really cares about the show's outcome, they need to have rigs that can handle less than perfect conditions sometimes too.
 
Re: LED Par cans cause buzz on some acoustic pickups

TJ Cornish said:
The best guitarists I know have tools to have their guitar sound not ruined by the interference du jour. This isn't necessarily convenience of the sound man - it's partnering with the sound man to have the show not suck. We need to find tools that work good (maybe the American DJ cans need to go in this case), but if the band really cares about the show's outcome, they need to have rigs that can handle less than perfect conditions sometimes too.
Click to expand...

Good luck with that, TJ. That's like asking the flailing, bashing drummer to play lighter.

Pat
 
Re: LED Par cans cause buzz on some acoustic pickups

Have you tried turning off the lights in question to make sure this really is the issue?
I only ask because I have yet to run into any trouble with any of the LED stage lighting I have encountered.
The old PAR lighting is a different story!
 
Re: LED Par cans cause buzz on some acoustic pickups

Pat Latimer said:
Good luck with that, TJ. That's like asking the flailing, bashing drummer to play lighter.

Pat
Click to expand...
I'm lucky that in most situations I'm involved in, I get to do exactly that. That's one of the benefits of not doing sound for my livelihood - I get to pick the gigs I take and avoid flaily-bashy drummers and lame single-coil guitar players.
 
Re: LED Par cans cause buzz on some acoustic pickups

Brian jojade said:
O.K, so this is a new one for me, and I'm looking for suggestions. Working in a smaller venue that is using American DJ LED Pro 64 par cans for lighting. They are about 10 feet up and about 12 feet from the front of the stage. Nothing too fancy, and they do the job well. Lots of different acts perform here, and usually things are just fine. However, with a few of them, the acoustic pickups in the instruments will pick up a buzz from the lights.

What is really interesting is that this seems to be an induced buzz, and no amount of filtering of the power will fix the problem. If the performer faces the front of the stage, there is buzz. If they turn away from the lights, the buzz goes away. I have gone as far as put the instruments on wireless body packs, and thhe buzz still happens. It's not your typical 60 hz hum. Using a midrange notch filter, we can sometimes limit the issue, but that's not an ideal solution.

So, I am looking for a solution to this problem, hopefully that does not involve replacing of the lights. Any ideas?
Click to expand...

Unfortunately, the problem you describe is caused by a noisy RF source (the cheap LED light dimmers) and pickups that are probably really low output, very high impedance.

If you are not using good active direct boxes for those pickups, which will often give a far better signal to noise ratio than even the best passive devices, that would be the place to start.

The wireless body pack is a good idea, but they are usually designed for magnetic guitar pickups, which have boatloads more output than some of the piezo transducers on acoustic instruments.

A single coil magnetic pickup has the shield connected to the strings, so by standing at the proper angle to a noise emitter (your lights) the noise can be reduced if the guitar player is touching the strings.

AFAIK, Piezo pickups don't usually have the shield connected to the strings, and even if they did, if the strings are gut (nylon) they would not connect the shielding to the player's body.

I am curious what type of direct boxes you are using with the noisy acoustic pickups.
 
Re: LED Par cans cause buzz on some acoustic pickups

Vinny D'Agostino said:
Have you tried turning off the lights in question to make sure this really is the issue?
I only ask because I have yet to run into any trouble with any of the LED stage lighting I have encountered.
The old PAR lighting is a different story!
Click to expand...

Yes, it is most definitely the lights. Turning them off, or not facing them and the problem is not there. To ensure complete electrical isolation, I even went as far as running the lights off of a UPS, not connected to the power grid at all, while running the guitar through a wireless body pack. The same problem happens.

Seems as though the single coil pickups are where the problem is, as it's not everyone that has the issue.
 
Re: LED Par cans cause buzz on some acoustic pickups

Those must really be cheap lights as I have yet to encounter any such issues with any LED lighting.
I know with the old PAR cans I never had much luck getting rid of the single coil buzz, and most guitarists will not want to switch there guitars......Just had to ride the mute button in between songs!
 
Re: LED Par cans cause buzz on some acoustic pickups

TJ Cornish said:
I'm lucky that in most situations I'm involved in, I get to do exactly that. That's one of the benefits of not doing sound for my livelihood - I get to pick the gigs I take and avoid flaily-bashy drummers and lame single-coil guitar players.
Click to expand...

I'm sorry. I just can't leave this alone. Lame single-coil players? Ok, I'll list some for you:

Eric Clapton
Jimi Hendrix
Jeff Beck
Joe Walsh
Neal Schon
Yngwie Malmsteen
John Mayer

Do you want me to keep going? I haven't even started searching online yet.

Stevie Ray Vaughn
Brad Paisley
Brian May
Eddie Van Halen
Eric Johnson
Prince
Tom Morello


I mean, good god man...
 
Re: LED Par cans cause buzz on some acoustic pickups

John O'brien said:
I'm sorry. I just can't leave this alone. Lame single-coil players? Ok, I'll list some for you:

Eric Clapton
Jimi Hendrix
Jeff Beck
Joe Walsh
Neal Schon
Yngwie Malmsteen
John Mayer

Do you want me to keep going? I haven't even started searching online yet.

Stevie Ray Vaughn
Brad Paisley
Brian May
Eddie Van Halen
Eric Johnson
Prince
Tom Morello


I mean, good god man...
Click to expand...
You missed my point Google Boy! :)

For the record, I suspect most of the aformentioned have more than one guitar.
 
Re: LED Par cans cause buzz on some acoustic pickups

TJ Cornish said:
You missed my point Google Boy! :)

For the record, I suspect most of the aformentioned have more than one guitar.
Click to expand...

What do you do when the guitarist shows up with 5 guitars, all single coils? Cancel the show?
 
Re: LED Par cans cause buzz on some acoustic pickups

Brian jojade said:
Yes, it is most definitely the lights. Turning them off, or not facing them and the problem is not there. To ensure complete electrical isolation, I even went as far as running the lights off of a UPS, not connected to the power grid at all, while running the guitar through a wireless body pack. The same problem happens.

Seems as though the single coil pickups are where the problem is, as it's not everyone that has the issue.
Click to expand...

I think Art has the answer. Which direct boxes are you using on the guitar? Are they passive?

Either those need to change to active (for the AC guitar) and/or the lighting needs to be upgraded. Audio technology has grown up in spite of high impedance guitar pickup technology. When I started, many systems were still completely high impedance, sometimes with the option to add transformers for low impedance mics. Although that was considered expensive. :twisted:

P.S. Is the show low enough level to use a mic instead of the pickup?
 
Re: LED Par cans cause buzz on some acoustic pickups

Steve Hurt said:
What do you do when the guitarist shows up with 5 guitars, all single coils? Cancel the show?
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Obviously you get the job done the best you can.

If a guitarist has trouble with buzz one one out of a hundred rigs - yours - then it seems reasonable to blame the PA, lights, whatever. If a guitarist has trouble on 99 out of 100 rigs, it is my opinion that the guitarist's refusal to examine the many reasonable ways to mitigate this issue in the interest of "tone" indicates that this person's priorities are misplaced.

Other gig-ruining ego issues such as guitar amps turned up past 11 in small rooms, drummers playing at arena levels with 2x4s, etc. are a detriment to (IMO) the band's best interest of being asked back and are equally unfortunate.
 
Re: LED Par cans cause buzz on some acoustic pickups

Tim McCulloch said:
You can keep Yngwie. He's an asshole.
Click to expand...

HA! Darn right. Have you ever worked with him? I know word on the street is that he is and you can totally tell from interviews, but I've always been curious to hear actual stories from people who have actually worked with him and experienced him first hand.
 
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