RF interference Audio Technica AT4053b

[lucasfdaf]

Hey Everyone,

 

I'm having some interference problems with my Audio Technica AT-4053b microphone that I use for intern booming (cabled to my zoom f8n pro). Recently I've done a sit down interview and had some noisy interference in my recordings, strangely it happened randomly during the day for less than a minute and then worked well for hours. I asked the people present to turn all the cellphones in airplane mode but I still had the issue happening.

 

Does anyone can help me figure out the possible cause tied to this interference? Is it something related only to cellphone or other types of RF?

I've read that one major downside of this microphone is its RF interference problem and I'm conscious of it, but is it possible to improve this downside in some way? (like trying to ground the microphone chassis to make a sort of faraday cage?)

 

Down here the video example in low quality and the unprocessed wav

 

[Conor]

There are many potential sources of RFI other than cell phones. DC wall wart power supplies, for example, are notorious for their broadband RF spray. You can attempt to filter out high frequency RF signals by putting a small polystyrene or similar capacitor between pin 1 and the shell of the XLR connector that is connected to the mic. Lectrosonics recommends a value of 330pf for lav mics used with their transmitters, I'm not sure what exactly would be the most appropriate value in this case. But even just grounding pin 1 to shell would enforce the faraday cage effect more.

[PMC]

Dont know if this helps any but I have heard plenty of 5G cellphone noise, which sounds like a combination of popping popcorn hitting a tin lid and and electrical storm crackling, but your noise reminds me of computer communications noise. 

 

Assuming you tried a different XLR cable, are you using star quad cable? I have the same mic in my arsenal and all my cables, including internally wired booms are all star quad. I have not experienced RF noise of any kind in the five years I have owned my AT 4053b. 

[Clay Reeves]

Aloha, I have used my AT4053b  for 5 years and never had any noise problems. I used Canaire cable and powered it with the 48 v0lts from the PSC box. I also had the AT4053 and it worked great. Thanks

[lucasfdaf]

Thank you all for your answers! A thing that I missed in my post is that I can't really recreate the same RF noises outside of that location, I've tried with calls, messages and internet messaging/usage, but I can't replicate that condition (that sucks because now it's difficult to evaluate if there could be some improvements in my setup)

 

10 hours ago, Conor said:

You can attempt to filter out high frequency RF signals by putting a small polystyrene or similar capacitor between pin 1 and the shell of the XLR connector that is connected to the mic. Lectrosonics recommends a value of 330pf for lav mics used with their transmitters, I'm not sure what exactly would be the most appropriate value in this case. But even just grounding pin 1 to shell would enforce the faraday cage effect more.

 

Are there any downsides or possible implications of putting the capacitor? A local technician suggested to ground pin 1 to shell of my XLR cable as you suggested, but warned me that probably it won't be the final solution but might only attenuate some kinds of RF and not others (i don't know why and how). If putting a capacitor it's a safe option I'll definetely try it. Thank You!

10 hours ago, PMC said:

Assuming you tried a different XLR cable, are you using star quad cable? I have the same mic in my arsenal and all my cables, including internally wired booms are all star quad. I have not experienced RF noise of any kind in the five years I have owned my AT 4053b. 

 

I've tried all the different cables that I had with me but all failed, I'm using standard XLR cables from Cordial with neutrik connectors (https://www.thomann.de/intl/cordial_cpm_10_fm_234.htm). Now that you mention star quad cables I'll try to buy those and it could solve a lot of problems! A question still comes to my mind, if the RF sensibility comes from the AT053b, is the shielding of the cable sufficient to eliminate any RF interference? It may be a dumb question but for my limited experience I still struggle to understand how RF, microphone construction ad their interaction actually works.

 

6 hours ago, Clay Reeves said:

I used Canaire cable and powered it with the 48 v0lts from the PSC box. I also had the AT4053 and it worked great. Thanks

 

I power my AT053b through the phantom of my Zoom F8n Pro, could there be any differences in powering it through a separate device like you do with your PSC box?