Blackmagic Forum

Hello,
I've ready other posts on similar subjects, but did not find quite the setup we have. We use a 22 channel mixing console to control audio in our church. We send the output of one of our 4 mono aux busses to our stream using the ATEM Mini Pro. The other 3 aux busses are occupied.

We accomplish this by using XLR cable from the console to a balanced -to-unbalanced inline style transformer, the output of which is a male TS 1/4" plug. This is inserted into a 1/4"(TS) to 3.5mm(TRS) adapter, and into the ATEM Mini Pro mic one stereo input. The resulting audio is mono, to the left channel.

I don't like this setup because a) it's left channel only, especially apparent for listeners with headphones, and b) the bulk of the inline transformer plugged into an adapter plugged into the ATEM is mechanically dodgy, and sometimes bumps loose; it's just too heavy. I don't like the mechanical stress it seems to be putting on the ATEM mic 1 input.

Questions:

1. Can the mono output of the inline transformer be split into identical left/right signals using suitable a cable that plugs into the stereo Mic 1 input, so that our listeners hear mono out of both speakers? If so, how do I shop for the correct cable for plugging into the mic 1 stereo channel? I had the impression not all TS to TRS adapters are wired the same, getting the impression from this forum that some will introduce problems of their own. In fact, when we purchased the 1/4" to 3.5mm adapter, there were two types to choose from, and one of them resulted in no sound at all.
   
2. If such a solution doesn't exist, what is an alternative set of hardware to consider that delivers two channel mono, bearing in mind that our source from our console is a single, mono XLR output jack from the only aux bus we have left.

Thank you

I appreciate your pain as it is only in the last few months that I have found a workable solution for connecting audio sources to the ATEM Mic input. I don't know if it will work for you - just that it works in my setup. Whatever plugged in had humm and buzz that I put down to an earth loop that I couldn't resolve.

I also have a digital interface in my kit that will take up to 4 inputs and send it out over USB. I was recording choirs so I connected that into the audio chain to get 4 x multitrack recording. This particular interface also has analogue outs and functions as a 4 channel mixer. While setting it up I thought I might experiment plugging the analogue outs into the mic input, and set the input to line level. Well it actually works! Both channels! Just finished another gig today with that setup. I did have a lot of teething issues with distortion, but I now know how to mitigate.

This is an old interface, and there was an app that came with it that gave you more control over the mixing process. However upgrades on my laptop have stopped this app out - I had to do a major reset - and I can't find the app anymore. This app would have helped hugely in tracking down the distortion.
Don't know if anything similar is available now, but it works for me!

Darryl

You just need the correct TS to TRS adapter, this one will do the trick.

https://www.amazon.com/Tisino-3-5mm-Ste ... 1672&psc=1

Good Luck

These work really well. Originally designed as a PC line out, they also work backwards. You'll need a gender changer.

https://www.interspaceind.com/products/pcbb3/

Howard Roll wrote:You just need the correct TS to TRS adapter, this one will do the trick.

https://www.amazon.com/Tisino-3-5mm-Ste ... 1672&psc=1

Good Luck

Sorry to be a pain but that is misleading. There are a lot more factors than just getting the wires in the correct place to go from TS to TRS.

For one thing XLR is Balanced and TS can only ever be Unbalanced so you are going to need a balun for that.

Then you have an earthing issue which is a major issue with the ATEM Mini's. They have a double shielded power supply which means no earth is directly connected to the ATEM at all. As soon as you connect an audio cable with an earth (TS or TRS), there is a mismatch between the floating earth inside the ATEM and the earth in the audio signal chain which is really hard to eliminate.

Then you just have mismatches with the impedances and signal levels between the XLR end and the TS/TRS end of the signal chain as per the OP's original question. The ATEM does allow you to switch the port between line and mic levels, but I am not sure what it does with impedance.This was one of the first things I tried, but I couldn't get rid of the earth loop noise so I don't know if the impedances matched properly.

It is a lot more complicated than just the right TS - TRS adapter. If it was, I would have solved this issue for myself years ago. In recent months I have seen a reverse DI box that purports to allow XLR mics/outputs to connect to PC's via the 3.5mm TRS. Had I not found the solution using the digital interface, I may have tried it.

Apologies if I am coming across abrasively but this is my experience with this situation and I hope to save others the pain that I went through.

Darryl

The OP is already using a transformer, if you’d spent half as much time reading as writing you’d probably get it, and it wouldn’t take years to understand.

Good Luck

Thanks for the feedback so far. As mentioned, I am already using a transformer, but I didn't clarify that I was NOT suffering hum issues. The only issue I'm trying to solve is having mono out of the left channel mic 1. My goal is to get mono out of both channels on mic 1.

The cable solution seems like it should work, except the output of my transformer is 1/4" male, so I would need a female-female 1/4" coupler to make the posted solution work. That seems like a reasonable adaption of the proposed solution(unless I can find a similar cable, but with 1/4" female mono input, which I will look for).

According to my discussion with a BMD tech, the best solution is to custom wire an unbalanced XLR to a mono 3.5mm jack, placing the hot on pin 2, instead of pin 1 on the XLR side, the ring should be hot on the 3.5mm side. I am wondering if a DSLR mic cable, like one from a Sennheiser MKE 600 would work. I plan to test that soon. I'll post my results.

FenderBender wrote:the best solution is to custom wire an unbalanced XLR to a mono 3.5mm jack, placing the hot on pin 2, instead of pin 1 on the XLR side, the ring should be hot on the 3.5mm side.

This will give you an unbalanced right only recording...and it's probably going to buzz. It's a far cry from the best solution. I'm going with this guy as my top choice. https://www.jensen-transformers.com/product/din-2li/

Pin 1 is always ground. If you're going to use pin 2 (and 1) for a mono unbalanced signal then pin 3 "should" be tied to ground on the XLR side (not left to float) but I've done it both ways.

Good Luck

Howard Roll wrote:You just need the correct TS to TRS adapter, this one will do the trick.

https://www.amazon.com/Tisino-3-5mm-Ste ... 1672&psc=1

Good Luck

Update: Howard, your suggested cable worked perfectly! The cable fits snugly, compared to the cheap adapter we were using, and now the sound is mono out of both speakers. All I needed was a female coupler to connect the 1/4" male mono output from our existing inline transformer to this cable. I'm sure our online headphone listeners will appreciate this!