UDM makes pulsating noise? 
 sound UDM ultrasonic 
 By Vince 

 on 6/3/19, 7:47 PM • 469 views
Anyone has experience this before:
Sound guy comes by telling me he can hear my Arri UDM pulsating (only with headphones directly aimed to the horns) when using a certain type/brand of microphone.
Anything that can be done or knows what the problem could be?
Link of tested microphone:
 http://www.ventoencanado.pt/images/equipamento/27D1322004785.pdf 



 Jesper Rey 

 On 6/5/19, 9:59 PM
I had this issue a some weeks ago. The boom operator on that shoot had done some tests regarding this issue on another shoot he was on. He had this theory that the amplitude sine waves coming from the UDM-1 are controlled by the "Sensitivity" setting. The higher the sensitivity the greater the amplitude (obviously). The ultrasonic waves are normally always picked up by microphones used on set but aren't really hearable to the human ear. But when the amplitude is so high, the peaks of the sine wave are chopped off by the limit of the bandwidth, resulting in something close to a square wave. This can result in digital artefacts, and that's supposed to be the pulsating sound the sound mixer picks up. 
Anyway, just a theory of his ofcourse, but interesting nonetheless. 
Lowering the sensitivity on the UDM-1 on that shoot actually did the trick for me. 
 

 Fabio 

 On 6/5/19, 3:27 PM
Had the same issue today using the cineRT. Camera was very close to the talents (4 1/2 feet), who were wearing a wireless mic and there was also a shotgun mic involved in the equation. Luckily it wasn’t a very difficult shot so I just unplugged the rangefinder. And the sound mixer told me that it was kind of a minor problem, that in theory could also be fixed in post.

 

 bart van otterdijk 

 On 6/9/19, 2:22 PM
I only had this issue once or twice with the CineRT. Much more often with the cinetape.
Luckily the CineRT has a solution for that. the 'Sonic Saver' mode in the Vitals page. page 48 of the manual.
Icon is a happy sound engineer wearing headphones. Click it and it turns green. It reduces the 'volume' and timing I believe of the ranger output. You can't use the bugs anymore.
I never used the function yet since just lowering the sensitivity to 30 was enough.

 

 Bastien Rébéna 

 On 6/4/19, 8:55 AM
Hi, 
i already had similar issues. 
Some sound Guy explain me that it could come from hf transmitter who don’t have enought high Cut filter so the beat of UDM is hear by the sound engineer. No solution except an other transmitter. 
 

 Fabio 

 On 6/13/19, 3:57 PM
I had an issue the other day, when the camera got closer than 1m to the talent the sound guy told me he had a very high pulsating noise, his theory was that the ultrasounds bounced in to the talent and got picked from the boom. I switched to the “happy sound guy” mode of the cineRT and that did the trick for a while but on another shot where the camera was even closer I had to disconnect the cineRT. We are going to make more “scientific” test whenever we have a little time.
