BUZZZZZ in audio at DVinfo.net

Brian Federal · November 16th, 2004, 09:18 PM

Hello folks,
Set up...XL1s, MA100, XLR plug into MA100 with attached SHURE MX184BP clip on with lav mic. I mean some serious buzzz. How do I get rid of this? How can I shoot with XL1s and avoid the buzzz. I mean I love a good buzzz just like the next guy but hey this is driving me nuts. Any help would be greatly appreciated. I am relatively new to all this and Audio has been Kicking my ass. If anyone has any ideas or can help point me in the right direction I would be forever grateful.
Thanks
Brian

Douglas Spotted Eagle · November 16th, 2004, 10:50 PM

First, are you using balanced cables?
Second, if not...how long is the run?
Third, could be a loose/disconnected ground.

Jay Massengill · November 16th, 2004, 10:52 PM

Also do you have any AC powered devices attached to the camera, such as a video monitor?

Brian Federal · November 17th, 2004, 10:56 AM

This system works fine here in the studio. I had a 9" JVC monitor attached to camera and did try to disconnect...no luck. The XLR cables are Prolink Monster Cable 20' with talent about 10' away. I had two Tota Lights on and these were plugged into a power strip but had to lose the ground (3 to 2 adapter) on both lights to go into some cheap dimmers (B&H $20).
I was also shooting on the first floor of a 50 story building. I had to use my onboard mic which is ok but had to move closer to the talent and mic pics up everything in the room. I do not have a boom mic. I want a system that will work and may need several options with me at shoots. Any help here as I really want to learn to bring in good audio because it is killing my production and costing much time and money.
Thanks
Brian

Jay Massengill · November 17th, 2004, 11:12 AM

First, don't defeat the ground pin on grounded equipment. It's dangerous and a liability issue.
Second, don't use cheap dimmers. They may be the source of your audio interference.
Third, 50-story buildings and downtown areas are very prone to sources of powerful interference. Since there's no way to get audio into the XL-1 without at least a tiny section of unbalanced cable, this may be a problem.
However, I think it's more likely coming from the other end. Your lav mic element or cable to its power supply may be picking up nearby interference. Can you substitute a totally different mic, like a handheld dynamic just as a test?

Brian Federal · November 17th, 2004, 12:22 PM

I do have a handheld and will try this as a test next time I am shooting in this space.I did use the handheld in the space a few weeks back
and had pretty good results. The handheld mic does capture a different sound quality than the lav...sounds a little colder and high pitched. The space looks great and really need a way to aquire good audio in it.( hand held mic creates a different feel to the video) I may try a boom. Do you have any suggestions on a good boom mic set up? Maybe a wireless system also. ( I am sure wireless brings up new problems but want to get a set up for this)
Thank you and to everyone that makes this forum available to folks.
The dimmers for the tota and omni are pretty expensive so was trying to make due with what I could afford. Thanks for the advice you are absolutely correct and have the new dimmers in the budget.
Brian

Jay Massengill · November 17th, 2004, 03:02 PM

Since you don't have phantom power for mics with your current setup, I'd probably recommend the AT897 with a good shockmount and windcover for boom use.
If you get a source for phantom power, that opens up a wider range of mics to use.
For wireless; AKG, AT, Sennheiser and Sony make systems in the $500 range that have battery-powered camera-mount receivers.
Be sure to determine what frequencies in your area are free from the interference of TV and DTV channels.
Personally I like the AKG system that uses the PR-81 receiver, although in your case with the XL-1 that might not go together well with an AT897 because you can't separately control the Mic/Mic ATT settings for each channel if I remember correctly. The Sennheiser K6/ME66 would be a better match for input levels to the PR-81 output, but it costs more than the AT897 and I don't think it sounds as good when used indoors. You should be able to rent these items in Charlotte and try them out first.
Lastly I'll suggest cheaper alternatives to dimmers: Scrims, Diffusion, Umbrellas and Reflectors. These usually result in better lighting anyway and won't change your color temperature. There are also a couple of different wattage lamps for each of these fixtures too.

Brian Federal · November 17th, 2004, 09:00 PM

Jay,
Thanks so much for your time and help.I will check out this equipment.
Brian

November 16th, 2004, 09:18 PM	#1
Brian Federal New Boot Join Date: Jan 2004 Location: Charlotte North Carolina Posts: 20	BUZZZZZ in audio Hello folks, Set up...XL1s, MA100, XLR plug into MA100 with attached SHURE MX184BP clip on with lav mic. I mean some serious buzzz. How do I get rid of this? How can I shoot with XL1s and avoid the buzzz. I mean I love a good buzzz just like the next guy but hey this is driving me nuts. Any help would be greatly appreciated. I am relatively new to all this and Audio has been Kicking my ass. If anyone has any ideas or can help point me in the right direction I would be forever grateful. Thanks Brian __________________ Brian

November 16th, 2004, 10:50 PM	#2
Douglas Spotted Eagle VASST Join Date: Jan 2004 Location: Stockton, UT Posts: 5,648	First, are you using balanced cables? Second, if not...how long is the run? Third, could be a loose/disconnected ground. __________________ Douglas Spotted Eagle/Spot Author, producer, composer Certified Sony Vegas Trainer http://www.vasst.com

November 17th, 2004, 10:56 AM	#4
Brian Federal New Boot Join Date: Jan 2004 Location: Charlotte North Carolina Posts: 20	More info This system works fine here in the studio. I had a 9" JVC monitor attached to camera and did try to disconnect...no luck. The XLR cables are Prolink Monster Cable 20' with talent about 10' away. I had two Tota Lights on and these were plugged into a power strip but had to lose the ground (3 to 2 adapter) on both lights to go into some cheap dimmers (B&H $20). I was also shooting on the first floor of a 50 story building. I had to use my onboard mic which is ok but had to move closer to the talent and mic pics up everything in the room. I do not have a boom mic. I want a system that will work and may need several options with me at shoots. Any help here as I really want to learn to bring in good audio because it is killing my production and costing much time and money. Thanks Brian __________________ Brian

November 17th, 2004, 12:22 PM	#6
Brian Federal New Boot Join Date: Jan 2004 Location: Charlotte North Carolina Posts: 20	Thanks Jay I do have a handheld and will try this as a test next time I am shooting in this space.I did use the handheld in the space a few weeks back and had pretty good results. The handheld mic does capture a different sound quality than the lav...sounds a little colder and high pitched. The space looks great and really need a way to aquire good audio in it.( hand held mic creates a different feel to the video) I may try a boom. Do you have any suggestions on a good boom mic set up? Maybe a wireless system also. ( I am sure wireless brings up new problems but want to get a set up for this) Thank you and to everyone that makes this forum available to folks. The dimmers for the tota and omni are pretty expensive so was trying to make due with what I could afford. Thanks for the advice you are absolutely correct and have the new dimmers in the budget. Brian __________________ Brian

November 17th, 2004, 09:00 PM	#8
Brian Federal New Boot Join Date: Jan 2004 Location: Charlotte North Carolina Posts: 20	Thank you Jay Jay, Thanks so much for your time and help.I will check out this equipment. Brian __________________ Brian

November 16th, 2004, 10:52 PM	#3
Jay Massengill Trustee Join Date: Jul 2003 Location: Burlington Posts: 1,976	Also do you have any AC powered devices attached to the camera, such as a video monitor?

November 17th, 2004, 11:12 AM	#5
Jay Massengill Trustee Join Date: Jul 2003 Location: Burlington Posts: 1,976	First, don't defeat the ground pin on grounded equipment. It's dangerous and a liability issue. Second, don't use cheap dimmers. They may be the source of your audio interference. Third, 50-story buildings and downtown areas are very prone to sources of powerful interference. Since there's no way to get audio into the XL-1 without at least a tiny section of unbalanced cable, this may be a problem. However, I think it's more likely coming from the other end. Your lav mic element or cable to its power supply may be picking up nearby interference. Can you substitute a totally different mic, like a handheld dynamic just as a test?

November 17th, 2004, 03:02 PM	#7
Jay Massengill Trustee Join Date: Jul 2003 Location: Burlington Posts: 1,976	Since you don't have phantom power for mics with your current setup, I'd probably recommend the AT897 with a good shockmount and windcover for boom use. If you get a source for phantom power, that opens up a wider range of mics to use. For wireless; AKG, AT, Sennheiser and Sony make systems in the $500 range that have battery-powered camera-mount receivers. Be sure to determine what frequencies in your area are free from the interference of TV and DTV channels. Personally I like the AKG system that uses the PR-81 receiver, although in your case with the XL-1 that might not go together well with an AT897 because you can't separately control the Mic/Mic ATT settings for each channel if I remember correctly. The Sennheiser K6/ME66 would be a better match for input levels to the PR-81 output, but it costs more than the AT897 and I don't think it sounds as good when used indoors. You should be able to rent these items in Charlotte and try them out first. Lastly I'll suggest cheaper alternatives to dimmers: Scrims, Diffusion, Umbrellas and Reflectors. These usually result in better lighting anyway and won't change your color temperature. There are also a couple of different wattage lamps for each of these fixtures too.