Pad XLR -20db can hear internal fan

I'm not sure if this is a recent thing or not. I have a new UMP and haven't used the XLR input at all until after updating to the beta 6 firmware. I noticed that the -20db is on by default for the XLR input, but when turning it off, I can hear the fan inside (or some other repeating mumble). With it enabled, I can't hear the sound.

Is this normal? I've been recording today with this setting on to reduce the audio, while still getting clean voice recording (-12 to -10 peaks). I'm just wondering why the toggle off for the -20 pad adds in this low hum. I understood this toggle to be off unless you needed it.

Unless the mic is mounted to the camera David, I do not see why you would hear a difference, unless the mic preamps calibration was also changed in the FW update. Also, maybe you are hearing ambient backgrounds sounds from the location. Try doing this test with the mic at least 19-feet from the camera and in a quiet location.
Cheers

Hey Denny,

It's a wireless receiver that's plugged in (Sennheiser g3) and I've moved the mic around, scanned and changed channels—that sound is still there with the -20db toggle OFF. With it on, I don't hear the sound (though I did have to boost the mic pack to be -18db instead of the default -30db gain). The receiver is at 0.

I can also hear the same noise when I switch the second XLR input from in camera to XLR (with nothing plugged in). It's very faint, but I hear a fan or some noise like that.

I suppose I can upload some samples with the audio boosted to hear better.

Just curious, what is everyone doing when connecting an XLR input? Are you leaving the -20db toggle on (blue) or are you disabling it? The default is on.

Ah, I think David, the wireless receiver is the source of the sound, this has been previously reported as an issue. Glad rhe +20dB pad removes it. I used a wired mic setup plugged into the camera through a Sound Devices MixPre D, so I was using Line Level, which is set to +4dB Unity, and no hum or similar background noise. I haven’t tried a directly connected Sennheiser mic yet, could do a test today and get back at you. But I normally use my mixer, and feed the camera with the AES output using a single XLR AES connection on the Pro/Broadcast Camera. Does the UM 4.6 have the AES Line inout option?

That said, using the Pad would depend on the mic being used and the sound level of the source being recorded. Live music, I would tend to use the Pad with any high outout mic, which the wireless receiver is an example of a high outout source. On the UM 4.6 I believe Rick does not use the Pad with his Sennheiser shotgun, which normal level audio sources, like an interview/wedding ceremony.
Cheers

Hey Denny,

There is a setting for AES, yes. I believe the Sennheiser needs to be on the Mic level, not line level right? Because, line level is almost no sound at all. With Mic selected, that's where the -20pad is turned on. Turning that off reveals some slight hum.

So here's my setup:

Mic (-18db internal) > Receiver (0db internal) > XLR1 on UMP set to Mic with -20db pad enabled.
This gives me clean noise. Usually I'll have the mic set to -30db internal, but I'm recording a lot of soft voices today.

My thinking with Line or AES is that those would be from sound boards or professional mixers. Since I'm doing a mic directly into the camera, I believe it's still Mic level.

Correct, a mic direct into the camera is Mic level input setting. I used an external mixer with a AES outout, and go a clean feed, but I am not running the new 6.x update either.

If you can hear the background noise without anything plugged in the camera, then it is coming from the camera pre amps.
Cheers

On the URSA Mini 4.6K Camera I’m running firmware 4.8. With the Sennheiser 416 MKH on phantom power, I’m not aware of any fan noise and I don’t think I have any pad set.


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