Blackmagic Forum

Hello everyone,

we are a podcast studio that's been using an ATEM Mini pro ISO for recording multiple camera.
We have two studios in which we use the ATEM, in each case we feed the ATEM with a sound output from either our computer (through a Antelope sound interface) or a Rodecaster. We plug that in the Mic 1 input of the ATEM, from a stereo 1/8 jack (different in each setup).
Everytime, the signal is just simply mono though : same thing on Left and Right.

9 times out of 10, there's no problem : sound is just like it is in my audio recordings.
But some times... and I don't see a pattern (it happens in both setups), the sound got weird in a way like there is a phase problem. The sound seems more powerful from Left channel, but the meter is the same on both channels.
When I open a PAZ-Analyzer on it, there's clearly a problem (when, most of the time it shows a straight up mono signal). When I "monoize" it, it's just filtered like a phase problem.

The fact that the problem just appears randomly is making it really hard to understand and I was wondering if you guys very heard of a problem like that ?

P.S : yeah i know i can easily edit the sound, but sometimes clients just want to leave right away with the file and I can't do it.

THANKS !

No one ?

If U get this problem , u can divide Stereo input into 2 mono input in ATEM settings .. And use only one channel .. If u sending mono signal into atem ..

This is my first post, but I have been reading this forum for quite a while. I think I am experiencing the same intermittent "phasing" issue described.

I teach Ham Radio Classes using Zoom and YouTube (Channel name: W4EEY). Our main switcher is an ATEM Mini Extreme ISO. This switcher feeds Zoom via the USB C Webcam interface. We use two Sennheiser XSW 2-ME2-A Wireless Microphones each feeding Mic 1 and Mic 2. The mikes are Mono and the same signals are applied to the Left and Right channels. We have been monitoring levels using the metering and headphones.

A student recently complained that the quality of Mic 1 was much worse than Mic 2 on Zoom. Investigation showed that the problem is being heard in Zoom, recorded and also passed to my YouTube Live Stream via a second ATEM Mini ISO.

Playing back the recordings and viewing the audio channels on an XY display shows that when there is a problem Mic 1 is not a diagonal line (as it should be) but has widened circular characteristics (as if it were stereo). I have screenshots but I can't figure out how to post or attach them here.

A video with the audio problem is this one: https://youtube.com/live/RpDWQYQE7jo

A normal video is this one: https://youtube.com/live/3ESrh6fi-Yo

Both use identical set ups. The normal video was shot one day later than the first.

I have now installed an extra sound card and can monitor channel phasing in real time from the ATEM Extreme's Headphone output and a Sound Card Oscilloscope.

We do have multiple cameras but we do not use the audio feeds from the cameras. But if I purposely turn on audio from a camera's built in microphone I do see a similar circular XY waveform (natural as this is a stereo microphone on the camera).

This problem is intermittent. Our next class is Tuesday night. I will be watching for the problem and will report back if I find something.

73 de W4EEY

This is a follow up to my earlier post.

We produced another Ham Radio Class last night. The YouTube Live Stream recording is here:

https://youtube.com/live/x40UaPCsB4U

As I was setting up I ran a test using our Sennheiser Wireless Mike into the ATEM Mini Extreme ISO's Microphone One input. I monitored the audio on an XY display using a Sound Card Oscilloscope. I immediately saw that the waveform was a circular pattern - not a diagonal line as it should be as a mono source. I unplugged power to the switcher and re-powered it again. The audio signal on the XY display was now a diagonal line!

The problem is in the ATEM Mini Extreme ISO. What the problem is I cannot say at this time (I will investigate further).

I was concerned that the problem could reappear during the Live production. But it did not.

If I discover anything else I will post here. The problem is intermittent.

73,

Gary W4EEY

Dear Colleagues,

I found the culprit! In my case I have the Mike 1 and Mike 2 inputs set to 3 frames of delay in order to maintain audio/video sync with my consumer grade cameras (Sony FDR AX53). This morning I fired up the system and got lucky in that the audio phasing problem occurred immediately. After running some checks I decided to run the ATEM Software Control program and look at my audio settings.

I clicked on the frame delay setting and adjusted the virtual knob to reduce the delay to two frames. The audio signal phase (as measured on an XY scope) immediately cleared. Adjusted to four frames. Still good. Back to three frames. Still good.

So the problem (in my case) is occurring in the audio delay portion of the switcher.

Hopefully Blackmagic Design will see this and come up with a firmware fix. Until then I will keep monitoring audio phasing.

Would be interested if others are seeing the same.

73,

Gary W4EEY