Microphone on IMS3000 + Dolby Atmos

[Luis Garcia]

Hi everyone, I'm asking if anyone has used a wireless or wired microphone through the IMS3000's AUX AES connection.

Any converters, consoles, or interfaces that might be useful?

This is the first time I've been asked to do this in a room with Dolby Atmos.

I'd appreciate any help you can give me.

[Shibu Paul]

https://www.aja.com/products/ada4

[Leo Enticknap]

This one is significantly cheaper.

Two gotchas, though. 1 - the AES3 output is a BNC connector, meaning that you'll need a correctly pinned BNC to RJ45 adapter to pass the output into the IMS3000 (it looks like Amazon has them, but check the pinouts). Secondly, there is no Phantom power (or if there is, the spec page doesn't mention it), so if your mic requires it, you'll also need a cheap mixing board to connect the mic to, with the analog output of that going in to the A to D.

What would be great to unlock the potential applications of the IMS3000's aux audio in is if a reasonably priced audio mixing desk (say, 8 channels mixing into a 2.0 stereo output) with an AES3 output pair were available. But from a quick look around online, it does not appear that such a thing exists.

[Carsten Kurz]

There is a cheap (even with added tariffs...) stereo A/D->AES/EBU available from China, through ebay. Don't know wether it works with the IMS3000, but, at that price, it's probably worth a try. Yes, you need a basic small analog audio mixer in order to use microphones. But as Leo says, this adds more options to an analog input for the IMS3000.

https://ebay.us/m/w3UrOj

You can also find second hand AJA ADA4 converters on ebay for comparatively little money. They offer proper balanced audio inputs, but need a mixer as well for connections to standard mics. There are multiple devices on offer, they are sort of a standard utility it seems.

https://ebay.us/m/1J7qyz

The ADA4 could be interesting as it has four configurable bidirectional converters. You could use 2 channel analog->AES/EBU plus 2 channel AES/EBU->analog to/from the IMS3000, which, depending on your setup, could offer more analog connectivity for the IMS3000.

If all you need is e.g. a basic wireless microphone, you may find some whose receivers offer not only a mic level, but also a line level output. This COULD work directly into a line level A/D, but even if, I would still opt for a basic mixer to have more options.

[Ryan Gallagher]

The other option if time is short and demands don’t permit ample time to test integrated methods, just rent in a small powered PA on sticks, complete with mic and mixer.

We often have a trivia game host during doors, they just bring their own little rig and it works fine, the one monitor covers our 1300 seat house for voice and music based trivia questions.

Could it be done via the cinema system, yes, but using their system seems to be their preference and works fine… so have not suggested alternatives.

[Ioannis Syrogiannis]

An independent and mobile public address system could be the solution to more "problems" than this, in more screens than one.
Admittedly, it wouldn't accommodate an emergency PA message, if you are looking for a way to introduce one.

[Ryan Gallagher]

An independent and mobile public address system could be the solution to more "problems" than this, in more screens than one.
Admittedly, it wouldn't accommodate an emergency PA message, if you are looking for a way to introduce one.

Done "correctly", and emergency PA wouldn't depend on the cinema or live system being powered on and functional. Our venue recently started trying to improve their response plans to various situations... and at this time they provided about 6 pre-recorded announcements we might be instructed to play. There are so many holes in this approach I don't know where to start, but their heart is in the correct place. This probably deserves a separate thread. Ignore this detour!

[Ioannis Syrogiannis]

Back to the subject, and just curious about what can and what can not be done, I wonder if an HDMI connection could do the trick and carry the microphone sound.
In most cases which demand microphone(s), the video source is alternative. And feeding a computer audio from an audio interface and then passing through via HDMI shouldn't be restrictively hard.

[Ryan Gallagher]

Back to the subject, and just curious about what can and what can not be done, I wonder if an HDMI connection could do the trick and carry the microphone sound.
In most cases which demand microphone(s), the video source is alternative. And feeding a computer audio from an audio interface and then passing through via HDMI shouldn't be restrictively hard.

HDMI audio embedders are also a stand alone products, would still need some kind of little mixer, but a similar approach to your suggestion, just without the PC.

Now if you were being asked to drive alt content slides simultaneously it has a real chance of being more plug and play than messing with the AES audio separately?

[Ioannis Syrogiannis]

Never having messed around with such a setup, including an IMS3000, I can't help but wonder.
Not in order to make it more plug and play, necessarily. The analog to AES seems a more straightforward solution to me.
Yet, I thought that -maybe- a computer with microphone inputs could hit two birds with one stone and be more readily-available*.

*Of course, I am thinking "Iceland", where shipping is never (or really scarcely) a day away from delivery. Mexico city is probably another case.

[Ryan Gallagher]

Never having messed around with such a setup, including an IMS3000, I can't help but wonder.
Not in order to make it more plug and play, necessarily. The analog to AES seems a more straightforward solution to me.
Yet, I thought that -maybe- a computer with microphone inputs could hit two birds with one stone and be more readily-available*.

*Of course, I am thinking "Iceland", where shipping is never (or really scarcely) a day away from delivery. Mexico city is probably another case.

Same, though I have used all the mentioned gear outside of a cinema context except the IMS. If both approaches are valid I would view the analog via a mixer to AES method as more of an integrator permanent solution. Those AES devices often have dip switches or USB setup steps required, not to mention service level experience/access to set up a custom format to use it on the IMS. On the plus side it is least likely to introduce extra delay.

The laptop with mic output included in the alt HDMI feels more readily accessible to a consumer/projectionist since they probably already have an alt+hdmi audio format. It has a potential perk too that alt content with audio can be seamlessly handled alongside the mic, not format switching required. Those embedders are kinda trashy products though, your PC plus USB mic interface might be more reliable. Though without a mixer you would have to do extra software work to include any sort of EQ on the mic, which is often needed. One could always add a mixer and then the laptop interface only has to handle stereo input instead of a balanced/phantom mic input.

Edit: The analog to AES device method can accept analog input from a laptop concurrently too, either with the addition of a Laptop DI, or using unbalanced inputs on the required mixer. So really no downsides other than extra configuration, unless one was hopeful to preserve better than stereo decoding on ALT HDMI content, some extra config or hurdles there.