Speakerphone with dial pad… tabletop speaker/mic connected to a video conferencing CODEC…. PC routed to speakers internal to a display or surface/ceiling mounted…. Three separate systems for these audio sources.
Ease of use…. System utilization…. Customer satisfaction…. Three reasons to consider consolidating multiple audio solutions into a single, integrated system.
Disjointed… Confusing…. Awkward…. How separate solutions in a single room may appear to end users, and by example, how the above information intentionally reads.
If audio calls are treated separately from video conferencing, and video conferencing is considered totally separate from other audio sources such as YouTube videos, it is quite possible to end up with multiple speakers and microphones in a single space, each performing a dedicated function. While this may have some advantages, it can add to complexity for the end user. For example, there are some situations where a speakerphone may be utilized for audio calls. A separate set of speakers is used when watching training videos, and then a third speaker/mic combination is set on the table during video teleconferences. This can occur due to a system evolving over time, frequently it is due to perceived budgetary constraints, occasionally it is because the speakers were included with the display, and often times it’s because the speaker/mic pod was recommended with the video conferencing unit. In a well integrated meeting room, all of these components can be tied together for a unified end-user experience.
This is typically accomplished with a conference room auto-mixer that also has Digital Signal Processing (“DSP”). For convenience, the terms “DSP” and “auto-mixer” are commonly interchanged. An auto mixer’s most common function is to take multiple microphones, mix them together and route them to an output. It can sense the level coming into a microphone and adjust the levels automatically. Presumably, the mic input with the highest level is the one picking up the person currently speaking. The mic inputs with low level may contain background noise or side conversations that make it hard to hear the primary talker. To help the primary talker be heard better, the auto-mixer turns down the level of the inputs containing the background noise. It can also adjust the level should the person talking become too loud or soft.
Conference room auto-mixers often provide connectivity for analog or VoIP telephones and a dial pad. This allows the microphones to be used for a standard telephone call. When routing a microphone to participants at remote locations (i.e., by phone, video conference, etc), it is possible for people to hear a distracting echo of their own voice when they talk. Imagine you are in conference room in New York talking on the phone. Your voice goes through the phone lines and eventually out a speaker at the far end in LA. In the LA meeting room, your voice bounces around the room for a few moments and is picked up by an open microphone in the LA location. The sound of your voice then travels back through the phone lines to NY and where you now hear yourself a few moments later. This is called acoustic echo and it is very distracting. To avoid this it is essential that an auto-mixer have Acoustic Echo Cancellation (“AEC”) any time a microphone may connect to remote locations. AEC works by analyzing the audio going through a microphone and subtracting this from the signal returning from the far end.
In addition to mic inputs, AEC, auto-mixing and Telco connections, DSP’s will typically have line inputs and multiple line outputs. The line inputs can provide connectivity from video teleconferencing units and from other playback sources, such as CD players or PC’s. Any input can be routed to any output using a matrix mixer that is internal to the auto-mixer. This allows the same microphones that are used for telephone calls to be routed to the video conferencing unit and extending their functionality.
Other outputs may go to an amp and speakers within the same room to allow for hearing any of the sources locally. This allows the same set of speakers to be used for telephone calls, video conferencing, training videos, and any other device. If local microphones are routed to speakers within the same room, this is sometimes called “voice lift” and is commonly used in larger spaces. Gain staging, signal processing and zone configurations within the DSP, are commonly used to minimize feedback from local speaker and microphone interaction.
Most auto-mixers can be controlled by third party control systems. Some provide the option to use a simplified controller that looks like a familiar telephone dialer with a couple extra buttons for system volume and source selection. When receiving requests for any one meeting room function, such as video conferencing, it is helpful to discuss the other elements of the room as well. This facilitates determining the best solution for space as a whole, minimizes redundant independent systems, increases system utilization, and improves the overall customer experience.
For more information on incorporating audio systems into meeting spaces, see the Almo Installments Blog: “So Many Choices, So Little Time: Finding the Right Automixer for Your Application”
Tips on cleaning up audio in a meeting room are available in the Almo Pro AV TechTip: “Spring Cleaning Your Audio: Basics of Audio Filters and EQ”