The most difficult challenge when recording meeting video: Recording Good Meeting Audio
by Rush Beesley, President, RUSHWORKS
Video is Easy.
There aren’t any ‘terrible’ video cameras these days. In fact, there are a myriad of tiny cameras with pinhole-sized lenses – often referred to as “cell phones” – that incorporate the latest technology and are available from many manufacturers.
With any current generation camera you can record (and stream) excellent HD video with minimal lighting. Overhead fluorescents provide adequate ‘soft light’ for any meeting venue. So just turn on the camera, frame your shot, and press Record.
Audio is not.
The variables involved when capturing audio in a meeting environment are many, and include
• Types of microphones (condenser vs. dynamic; wired vs. wireless; analog vs. digital)
• Audio pickup patterns (omnidirectional, unidirectional, cardioid, hyper-cardioid, ultra-cardioid)
• Local microphone control (user and/or remotely selected On/Mute)
• Audio mixers and signal processors (analog vs. digital)
• Audio power amplifiers vs. powered speakers
• Room sound support (ceiling vs. stand-mounted speakers; one or multiple speaker ‘zones’)
• Integration of Zoom, Teams and other remote meeting software with in-room sound support
• Meeting participants generally do not understand how to interact with a microphone
Here is a summary of the basics to help you make ‘sound’ decisions for your room.
Types of microphones
Condenser microphones have a higher output level and capture the important frequencies in the human voice. Since a dais or grouped tables are likely featured for the participants, ‘gooseneck’ microphones on weighted bases are ideal.
There are dozens of choices on Amazon, Sweetwater, B&H and more, but consider the Shure MX418D/C 18-inch Cardioid Gooseneck Microphone with Desktop Base and Preamp as your ‘go to’ for the room. The pickup pattern appropriately rejects ambient noise, reduces feedback potential and accommodates the widest range of participant positions.
Wireless microphones can be great problem solvers and problem creators at the same time. There is generally no local control of On/Off that your participants can easily use, so bathroom breaks must be muted by the operator. For current technology at a great price check out the Rode Wireless Go II and DJI wireless kits that provide excellent and stable wireless performance on a budget.
Just select one with enough XLR inputs to accommodate your wired and wireless microphones. All will provide input level control and EQ for each input. The most important thing to know is how to set the input level for each microphone. Always follow this procedure.
- Set your mixer MASTER level fader to the 0dB position.
- Move the fader/rotary pot to the 0dB position, usually about halfway on the fader.
- With the person talking normally into the mike, rotate the input GAIN pot (+4 to -60dB) until the level meter/LED peaks before showing red. This assures an optimal signal level for that participant/microphone.
Yamaha is among many manufacturers offering excellent alternatives, some with USB output. MX12XU shown here.
Audio signal processors
Analog audio signal processors manage audio levels by limiting, compressing and expanding the signal so the level stays consistent. The manufacturer dbx has provided these solutions for decades, and they’re still viable and inexpensive, like the Model 166x. Digital Signal Processors (DSP) use intelligent algorithms to manage levels and EQ, but they’re typically more expensive and complex to use. These are often associated with Dante™ digital audio systems.
Audio power amps, speakers and powered speakers
Before powered speakers became widely available, the signal path was always from the analog output of your audio mixer (line level) to one or more audio amplifiers, typically in rack-mount configurations. The power amps are connected to ceiling and/or wall-mounted passive (non-powered) speakers. 70V speaker systems are networks of loudspeakers which are connected to an audio amplifier using step-up and step-down transformers to simplify impedance calculations and to minimize power loss over the speaker cables. Powered speakers bypass the need for amplifiers, with the line out(s) of the mixer connected to those devices. Either method is fine, but powered speakers are the easiest to setup and use in many meeting spaces.
Remote participant audio integration
‘Hybrid’ meetings, that combine participants in a room with remote meeting software, are now largely an accepted form of municipal gatherings. But managing the interactive audio is a challenge because of how the signals are routed in your audio mixer. This can cause the annoying ‘feedback’, or round-robin echo that plagues such configurations. This is solved by creating a “mix minus” output on your mixer providing at least one ‘aux’ output sending a different mix of inputs to that output. The company ZOOM makes a lot of excellent and affordable audio gear, including their LiveTrak L-8 and L-12 mixers. Not only can they record individual inputs, but they also support three independent aux mixes that resolve remote meeting audio perfectly.
Summary Understanding the variables in audio production is critical in making the proper choices and optimizing your audio-for-video, which is certainly the most important aspect of your meeting recording. But I do recommend conducting a ‘class’ with your participants before the event to demonstrate how to, and how not to, interact with their microphone. Prevention is always the best alternative to an expensive cure.