Setup for Hybrid Workshops

Abstract

Hybrid: From Latin hybrida, a variant of hibrida. Something of mixed origin or compo­sition; often, a tool or technology that combines the benefits of formerly separate tools or technologies.

(Source: Wiktionary)

Hybrid workshops allow people online and on-site to collab­orate, both in education/training, or other types of meetings.

Before COVID-19, workshops and trainings were commonly held in a meeting room or event space (“on-site”). That changed to pure online meetings (with Zoom, WebEx, MS Teams, or similar video confer­encing software).

More recently a third kind of workshop became more important – the hybrid variant: Some people gather on-site, others partic­ipate online.

Figure 1: Online vs. On-site

In this post you learn how to set up such hybrid workshops, you learn about challenges and pragmatic solutions to conduct such events yourself.

Hybrid? Isn’t online the new normal?

Some people really got tired of online meetings and events during the pandemic, and really longed to meet people in real life again – zoom fatigue became a real thing. Let’s call this group the onsiters. Others have gotten used to working remotely from their home office, they don’t like to travel, they want to save travel expenses or have other reasons to prefer online partic­i­pation. Let’s call the latter the onliners.

In my profes­sional life I both do consulting work and conduct trainings – both activ­ities are heavily based on inter­acting with people.

Online sessions with Zoom, WebEx, MS Teams, or BlueJeans were the new normal for several months during the beginning of the pandemic. It works reasonably well for all kinds of IT endeavours, but has consid­erable downsides. I’m sure all onsiters know what I’m refering to – a video call is simply not the same as a face-2-face chat in the coffee kitchen or over a real lunch.

In the last few months, I encoun­tered a strong demand for combining online and onsite workshops. In an increasing number of my trainings, some people wanted to join onsite, others weren’t yet allowed to travel or simply preferred to partic­ipate online due to other reasons. Keeping both groups separated didn’t seem reasonable to me, therefore I searched for solutions capable of combining both worlds, without compro­mising workshop efficiency (and fun!).

For my research I visited hybrid confer­ences, inter­viewed technology experts and event organizers, and of course watched several hours of YouTube tutorials. The outcome: A pragmatic setup that is affordable and got battle-tested.

Our Hybrid Scenario

Before we dive in, let’s look at the generic scenario, with some people on-site, others online. Our workshop groups have a size of 5–24 people. See the section on larger groups.

Every workshop has a moderator, facil­i­tator, or trainer – sometimes two of these. I’ll call them trainer for short. At least one trainer works with several people in a room, others partic­ipate online. Slides, documents, or other content are displayed on a large screen via a projector.

Figure 2: Generic hybrid scenario

Requirements for Hybrid Trainings

Must-Haves

• (R1) Visible trainer: Trainers shall be visible at all times for everybody else
• (R2) Excellent trainer audio: Audio quality of trainers shall be crystal-clear without distortion
• (R3) Visible room: Every online partic­ipant should be able to see the onsite event space at all times
• (R4) Visible online partic­i­pants: Every onsite partic­ipant should be able to see and hear all online partic­i­pants at all times (provided their webcams are enabled)
• (R5) Everybody can always be heard: Every onsite partic­ipant can hear every onliner, if the latter speaks – and vice versa
• (R6) No acoustic feedback: There must never be any disturbing acoustic feedback
• (R7) Working groups: It shall be possible to collab­orate in several smaller working groups during breakout sessions
• (R8) Thrifty: No additional personnel shall be needed to operate video or audio equipment (provided all trainers are capable of handling such)

Nice-to-Haves

• Excellent trainer video: Video quality of trainers, moder­ators, or facil­i­tators shall be excellent (at least HD resolution with natural colors). Use a DSLR camera with decent lense, if possible
• Joint working environment: Onsiters and offsiters shall be able to collab­orate on artifacts or documents

Prereq­ui­sites

The event space needs to be equipped with appro­priate internet connec­tivity, either wireless or wired connec­tions. Roughly approx­i­mated, a video call needs at least 2MByte/second for each partic­ipant in the room, both up- and downstream. Such capacity can be handled by conven­tional wireless routers, although I suggest to use cable-based internet access at least for trainers or presenters.

Another obvious prereq­uisite is some online video platform. We have become quite fond of Zoom, but the general setup is similar with others. Please beware – some features of my setup will work only if your video platform supports virtual cameras (see below).

The Minimal­istic Approach

Setup of two cameras, two micro­phones, and two notebooks, as shown in the following diagram:

Figure 3: Minimal­istic setup

Minimal­istic (and FAULTY) setup

• The trainer camera captures the trainer at all times, supported by a dedicated trainer micro­phone. Both are used as input for the trainer’s video session and trans­mitted to the online participants.
• A second camera captures the on-site partic­i­pants, likely in a panoramic view of the room. A second micro­phone enables the onsiters to speak to the onliners. For this to work, you will need a dedicated notebook plus a second video session.

With this setup, we have requirements R1-R3 covered, but R4 and R5 are still missing. To cover R4 (visible online partic­i­pants), we need a large-enough monitor to display a gallery view of all onliners at all times. You can connect that display to the room notebook.

Image 1: Sample room view

In my first hybrid training, I set up all those devices, and optimisti­cally thought I could easily achieve R5 (everybody can be heard) by attaching a speaker to the room notebook. But screeech – an awful acoustic feedback reminded me that this setup needs to be improved! Let’s step back and discuss acoustic feedback before we continue:

Acoustic Feedback

In case you think that a section on a physical phenomenon is a waste of time – please read on: It’s really important that you get a basic under­standing – as acoustic feedback proved to be a (if not the) major challenge in setting up hybrid trainings.

Let’s ask Wikipedia about acoustic feedback, as they are known for concise and often clever answers:

Before you read the expla­nation, you can listen to an example (it’s really awful, imho).

Audio feedback (also known as acoustic feedback, simply as feedback, or the Larsen effect) is a special kind of positive loop gain which occurs when a sound loop exists between an audio input (for example, a micro­phone or guitar pickup) and an audio output (for example, a power amplified loudspeaker). In this example, a signal received by the micro­phone is amplified and passed out of the loudspeaker. The sound from the loudspeaker can then be received by the micro­phone again, amplified further, and then passed out through the loudspeaker again.

It’s fairly easy to get this kind of (unwanted) acoustic feedback, if you open more than one online video session in the same room. Try it out – open a video session (e.g., with Zoom) on your computer, and dial into this same session with your smart­phone. Now turn on audio on both devices. Awful, isn’t it?

The modern video platforms avoid acoustic feedback to a large extend – but if you operate several sessions in the same room, you need to take some extra measures.

Room Audio Setup

As a solution, connect all micro­phones and the speaker to the trainer notebook. Notebooks have only a single micro­phone input jack – but appro­priate adapters can help.

The following diagram illus­trated the proposed room audio setup, and the image below shows my concrete solution, based upon Røde micro­phones and adapter. That kind of audio setup can be managed by a single person, as nothing needs to be adjusted during the training.

Figure 4: Centralized audio

Image 2: Røde setup example

By now, we covered all requirements R1-R8, the setup is quite easy to operate by a single person.

Figure 5: Complete setup of cams and mics

Two trainers

Two trainers who take frequent turns make trainings more effective and fun. The downside: They require even more equipment in hybrid trainings.

For my trainer colleague, I connected a third (wireless) micro­phone to a USB-Audio adapter, as shown in the image below. These little guys imitate a soundcard – your computer recog­nizes them as USB sound devices.

Image 3: Third micro via USB

But now another challenge arises: Zoom can handle only a single audio input, but now our trainer notebook has two distinct audio sources. Luckily, there are several fancy solutions to combining audio sources. I prefer Loopback, as I’m working on MacOS. Sound­flower is a well-known alter­native. For other operating systems you need to search for virtual audio software.

Loopback can combine arbitrary sound sources to a single (virtual) audio device. In my Zoom session, I simply select that virtual device.

Image 4: Loopback screenshot

Improving Immersion for Onliners

As a trainer, I love to walk around rooms instead of sitting in front of my camera. Movement creates attention and action within a room, and I propose you to stand or walk when teaching. But your teacher camera has a fixed position, optimized to capture your face and shoulders in a sitting position.

Therefore, I propose a third camera, aimed at the complete front of the room, the trainer-panorama cam. Most likely this will be a wide-angle lens cam. It either needs a third video session plus notebook, or you manually switch perspec­tives, e.g., with OBS.

Figure 6: On-site meeting room with 3 cameras

The geeks among you readers might use an Elgato Streamdeck to change the camera from OBS with a push of a button. Although it is tempting, I personally use my Streamdeck only at home, but not in hybrid trainings, mainly to minimize the equipment-count. Changing OBS scenes requires only few clicks, that I can handle in trainings.

Below you find an example of the proposed panaroma view (photo courtesy of M. Meng). You can see the two trainers (fyi: Carola Lilienthal and Gernot Starke) plus the front part of the room, where both often walked around.

Image 5: Sample panorama view

Organizing Hybrid Working Groups

My groups were homoge­neous, that is consisting either of onliners or onsiters. Mixed approaches would require additional equipment or zoom sessions, and there would be the immediate risk of acoustic feedback in the room if there are no additional real rooms available.

Therefore, keep things simple: Divide the on-site partic­i­pants into 2–3 groups, and the online partic­i­pants as well.

Use collab­o­rative white­boards for all groups, as the results of the different working can be shared among everybody. Yes, you’re right: It requires the onsiters to have access to a tablet or notebook, but one of these devices suffices for every working group.

Virtual Cameras

A virtual camera enhances your possi­bil­ities regarding the content you show to your audience, as you are no longer limited to your real camera’s output. With a tool like OBS you can blend in arbitrary media, images, timers, or even multiple cameras at the same time.

In addition, you can easily switch from one camera to another, providing a more varied visual experience for the onliners.

Some video tools don’t allow the use of such virtual cameras, though. Zoom and OBS collab­orate like a charm – so I personally favor that combination.

Some Tips (aka lessons learned the hard way)

• Perform a technical check at least one full day prior to your training. You will surely have forgotten some detail, and might need to fetch the missing cable, adapter, or other gear before your partic­i­pants arrive.
• Use cable-based internet access instead of wireless connec­tivity, especially for trainers.
• Provide a redundant commu­ni­cation channel accesible to everybody, even without internet access. I propose to use Signal messenger, as it’s available on smart­phones for free, highly secure, and free to use.
• When assigning people into working groups, make a screenshot of the mapping of people to groups – as they will want to work in the same groups the next day.
• Store the chat protocol of your video session in your shared drive for future reference.
• Ensure that you or somebody else conti­nously monitors the onliners and the online chat. That is one more reason to conduct hybrid trainings with two trainers.
  • A second screen for your trainer notebooks provides the screen estate required for that monitoring. A tablet (like iPad) is sufficient.
• If you work with two trainers, use an HDMI switcher to share a single projector with two trainer notebooks. You don’t want to switch cables during a lecture or session! Alter­na­tively, you could also project the video call, which means the same screen­share is visible to everyone – no matter if online or onsite, possibly even showing online partic­i­pants in addition.
• Provide a common online collab­o­ration tool for questions and answers, for example a joint Miro board (we called it our “Wall-of-Fame”).
• Bring a large-enough USB hub (or a suffi­cient number of chargers including a large power distributor) for every wireless micro­phone (sender and receiver). For our three Røde-Wireless-Go we needed six chargers, so we could recharge every­thing during breaks.

Image 6: Hybrid training example (Hamburg, November 2021)

Hardware / Equipment Summary

• Three cameras, at least two with high resolution clean video output (HD is suffi­cient). I suggest to use DSLR instead of WebCam, at least for the trainer and panorama cam.
• If you use DSLR cameras: 
  • Appro­priate HDMI to USB converters (like Elgato Camlink or similar)
  • Dummy batteries to power the cameras
  • If your room is large, a wireless HDMI trans­mitter replaces dangerous cabling chaos
• Three tripods to mount the cameras
• Three notebook computers, one for each of the three required video sessions (see above)
• A loudspeaker capable of suffi­ciently filling the entire room with sound. I use a Bose Soundlink, a Marshal Emberton is a great alternative.
• A monitor suffi­ciently wide to display the onliners in a gallery view, so that the onsiters can see their companions. I suggest 31 inches or more. If your room is large, you should duplicate that display in the back half of the room with an HDMI splitter. The high-tech option: Use a second projector for the onliners’ gallery view.
• Learn OBS. It enables visual variety, lower thirds, timers, and all kinds of other gimmicks your partic­i­pants will like.
• Even with profes­sional equipment such as DSLR cameras and high-end micro­phones, make sure the room has adequate lighting and acoustics.

Handling Larger Groups (30–150 people)

I have no personal experience in handling larger groups myself, therefore I can only give broad advice here (my colleagues at INNOQ have, and they are currently writing up their experi­ences with organizing hybrid events with up to 150 participants…)

Larger groups might require loads of additional equipment and handling.
You will definitely need a more complex setup for acoustics, e.g., larger and more powerful speakers plus a reasonable number of wireless micro­phones for the onsite audience. More micro­phones will require an audio mixing device – and you will need somebody to setup and operate it. Some confer­ences had people walking around the room with the micro­phones – whenever someone from the audience wants to speak, they walk up to this person and pass the microphone.

Another issue in large rooms is camera coverage. You might want several cameras capturing the onsite audience, so the onliners can see the people onsite.

Credits

• Thanx to Dr. Carola Lilienthal, Petra Gramß, Michael Brosius, and Julian Gersch for their support in organizing a hybrid workshop in Hamburg, Germany.
• Thanx to Martina Meng for supportive review and improvement of the overall setup (and this post).