This system design template shows how the Tesira beamtracking microphone can be used in a typical small conference room installation. Traditionally, these rooms are designed to allow room participants to host local meetings with one another using local presentation capabilities, as well as make conference calls to remote meeting participants over the phone (VoIP or analog POTS) or using a PC-based soft codec.
In this example, the conference room will be equipped with a beamtracking pendant microphone, placed above the center of the table, to cover the entire seating area. Meeting attendees will be automatically tracked and picked up by the ceiling microphone, which eliminates any user intervention. Tesira's Acoustic Echo Cancellation (AEC) technology and the TCM-1 beamtracker work together to deliver optimum speech quality to the far end participants. Ceiling speakers are located at suitable positions to evenly cover the room with the far-end voice, USB audio, or auxiliary audio. Amplification for the speakers already comes with the TCM-1A beamtracking microphone, which makes it a genuine one-cable solution and greatly reduces the installation effort. The TesiraFORTÈ AVB VT4 can also interface with analog telephone lines or a VoIP telephony system to allow for a voice-only telephone conference. There will be an HD-1 hardware dialer in the room located at the conference table as an additional control point for dialing functions.
Room Functionality Scope:
- Ceiling pendant microphone with beamtracking technology
- Connection to building phone system (VoIP and/or analog POTS)
- USB connection to local PC for soft codec
- Stereo program source audio inputs
- System control via third-party control system, and HD-1 dialer hardware.
- LoZ ceiling speakers for playback of voice signals (VoIP, soft codec)
Below is the list of Biamp equipment used in this project:
- 1 - TesiraFORTÉ AVB VT4 4 mic/line level inputs with AEC; 4 mic/line level outputs with integrated VoIP, POTS, and USB audio
- 1 - Tesira TCM-1A AVB beamtracking ceiling microphone with built-in 2-CH amplifier providing 2x 40 Watts burst power
- 1 - Tesira HD-1 Dialer Hardware-based dialer; 12 button dial pad with access to all Tesira telephony functions, PoE-powered
Note that other non-Biamp equipment is required, including the, PoE+ injector(s), speakers and a network switch.
The example file for this system design template is set up with all the audio I/O, processing, and control points required, and is ready to load to the system and begin setting up the room gain structure and EQing. In the file, the matrix routing is already in place to support the room design requirements. One AEC processing channel on the TesiraFORTÉ AVB VT4 will be occupied by the TCM-1A microphone. The first two analog audio inputs are used for the stereo audio feeds from auxiliary sources. No analog outputs will be required in this setup, as the speakers are being connected to the TCM-1A amplifier, represented as a separate two channel output block.
To support the conferencing needs of the space, the microphone signal is routed to the VoIP, analog telephone (POTS) and USB outputs. USB initialization in the file has been setup to support a 1x1 audio configuration with computer AEC disabled for the PC connection. All AEC references have been made in the matrix mixer for proper echo cancelation of conferencing sources. The file's Equipment Table is populated with proper hardware to match the layout, but will need to have serial numbers and proxy host assignments added before loading the file to system.
Even though the analog telephone interface is considered an optional method for conferencing in this design template, it can be found pre-configured in the system configuration file. Either VoIP or POTS may be used on demand to accommodate for the preferred connection method with the telephone system.
The .zip file below contains the example Tesira configuration files for this conference room application.
This conference room application will make use of single-cable AVB connection between the TesiraFORTÉ DSP and the TCM-1A. A regular Cat.5e (or better) peer-to-peer connection between the two devices will connect audio, control and power altogether. In regards to cable types and lengths, the common rules to Ethernet cabling do apply. The control port of TesiraFORTÉ as well as the HD-1 dialer must be connected to the same network, typically the control network which might be shared with other AV devices. As per factory default settings, the devices will look out for a DHCP server on the network or, in its absence, will self-assign a Zeroconf address. Static IP addresses may be assigned if desired, but make sure to change the remote devices first and the Proxy device (in this case the TesiraFORTÉ) last. For a more detailed guide on how to implement in a larger range of network applications, it would be helpful to reference our Tesira Network Infrastructure article.
- Control network switch with sufficient ports
- Optional: PoE capable switch to provide power for the HD-1 Dialer
- 802.3af (Class 1) PoE injector for powering the HD-1 (unless the Control switch provides PoE power).
- 802.3at (Class 4) PoE+ injector for powering the TCM-1A (unless an AVB switch is used, providing PoE+ power).
- The HD-1 is configured to receive an IP address by a DHCP server on the network or via Zeroconf addressing scheme.
- Note that the TCM-1A uses Layer 2 AVB for audio and control data, IP address setup is not required.
After these control and AVB network setup steps are complete, you will now be ready to send your compiled system configuration to the hardware.
Microphone and speaker placement
Arguably the single most important element in a conference system is the room itself. A noisy and reverberant room will generally sound awful for conferencing. A properly designed room with controlled reverberation and low noise floor will generally sound good for conferencing.
The importance of creating a controlled acoustic environment cannot be overstated. It is important to make the room as quiet as possible (lower noise floor) and minimize reverberance (shorter RT60) in preparation for installing the conferencing system. When properly applied, soundproofing and acoustic treatments will yield dramatic improvements in performance for most rooms.
Even though the TCM-1 beamtracking microphone uses state of the art technology to track a person's voice, while reducing unwanted background noise, the laws of physics can't be ignored when deciding on the right placement of a microphone. A good signal-to-noise ratio is key in every part of the audio signal chain and for a typical microphone pickup scenario, this translates to avoiding large distances between the mic and the talker. The TCM-1 Calculator will help to find the right pendant height for the expected coverage area. Here are a few more tips to an ideal microphone placement:
- Keep the distance to the talker as short as possible.
- Keep the distance to the ceiling speakers as high as possible.
- Stay away from noise sources like projector fans and air vents.
Placing speakers in a room can be as equally critical as finding the right spot for a microphone. An ideal positioning of multiple ceiling speakers will achieve an even SPL coverage and a good speech intelligibility across the entire room. In order to get a better sense on how much SPL the speaker of choice is able to produce with the given power of our TCM-1A amplifier, the Amplifier Power Calculator will provide some answers. In addition to that, a speaker simulation software might be able to predict the expected in-room STI values.
In this example, the speakers are not being used for voice-lift or similar live speech reinforcement, hence gain before feedback doesn't have to be considered. Still, avoiding short distances between the speakers (far-end audio) and the microphone will help to improve the AEC performance.
- Follow Gain Structure best practices to set input and output levels of microphones and sources. Input and output gain levels have been left at default settings for integration flexibility of the file. Input and Output metering has been added to assist with setting gain structure within the file. Additional meters can be added to the file as required to allow for additional detail at point along the signal path.
- Ensure that the proper VoIP and/or Analog Telco setup is done and the system is ready to make and receive calls.
- Connect USB to PC for soft codec integration if required. Reference the USB interface setup document if needed.
- Reference AEC best practices documentation and begin to do some test calls with the system. ERL values between 0dB and +15dB are optimal.
- Level and mute controls have been added to the file pre and post matrix mixer. These are added for flexibility to meet the design criteria and tastes of the client or integrator. These level controls have been left with their default maximum and minimum values in place, but can be adjusted to fit the needs of the space.
- The HD-1 hardware has tactile controls for level and mute functions. It is important to note that these control level and mute parameters on the VoIP or telco blocks themselves, and cannot be assigned to the standard level controls.
- Uber Filters have been added to all signal paths to allow for any additional equalization as needed to sources. It is recommended to use the advanced filters section of the AEC channel processing block for any high pass filtering needed on conference table microphone inputs. Additional filtering or dynamics blocks may be added or changed as needed to achieve the desired results in the file.
- Changes to matrix mixer can be made as needed to allow for appropriate sources to feed the speakers to fit the design application.
If a VoIP phone line is to be used, it must be correctly configured to register with the in-house VoIP phone system. Biamp VoIP interfaces have been tested and/or certified to work with the VoIP telephony systems listed here. Biamp VoIP interfaces may also be able to work with other SIP-based VoIP systems, but they haven't been tested or certified with those systems.
When integrating Tesira with one of the tested/certified VoIP systems, it is best to follow the detailed instructions in the appropriate article to ensure a successful deployment. Detailed instructions can be found in the following articles:
- Microsoft Lync / Skype For Business
- Cisco CallManager
- Mitel 3300 ICP configuration for a Tesira SVC-2 or TesiraFORTÉ VI
- Avaya Session Manager
- Avaya SES
- Avaya IP Office
- Avaya Communication Server
The basic steps to configure the VoIP interface start with opening the VoIP Control/Status block configuration dialog to access VoIP settings:
Click to see the configuration dialog
There are some required fields in the Network and Protocol tabs of the VoIP Control/Status block that must be filled in correctly for successful VoIP endpoint registration:
- Network Tab:
- IP Address / Netmask /Gateway - The VoIP card must have an appropriate IP configuration for the network it is connected to
- VLAN Tagging - If the VoIP card is on a "tagged" VLAN, this must be enabled and the correct VLAN ID must be provided. If the VoIP card is on an "untagged" VLAN (or no VLAN), this should not be enabled.
- Protocol Tab:
- SIP User Name - This is usually the extension number that the VoIP interface will use.
- Authentication User Name / Password - The username and password required to authenticate this extension.
- Proxy Vendor - Selecting the correct vendor will ensure that the VoIP interface correctly tailors its communications to the VoIP system.
- Proxy Address - The IP address of the VoIP proxy server (also known as: VoIP server, Call Manager server).
Much of the above information must be obtained from the customer's IT or VoIP team. The following document was designed to facilitate the process of obtaining this information. Provide this documentation to the IT/VoIP team and ask them to fill it out:
VoIP Checklist Form
HD-1 Setup: The HD-1 dialer in this system is a standard Ethernet device and requires 802.3af Class 1 PoE. The default network configuration of HD-1 units is DHCP, so if there is no DHCP server on the Tesira network the units will revert to link local addressing (169.254.xxx.xxx, netmask 255.255.0.0) schemes. The HD-1 will display "Waiting for Configuration..." on the screen until a configuration file has been loaded to the Server associating it by its Device ID. The Device ID of the HD-1 is used to associate the block with the physical HD-1, it needs to be set in 2 places: the HD-1 processing block and in the HD-1 hardware. The HD-1 must be associated with a specific telco card in the software. The HD-1 and telco card will then share an identification number seen at the bottom right corner of the blocks. It is also important to note that the buttons on the HD-1 have fixed functionality and cannot be programmed in the software to perform specific functions. The complete HD-1 configuration article can be found here.
Control System Integration: The example Tesira configuration file for this application has been set up to allow third-party control systems to easily control the Tesira system. There are control points for Dialing, Level, Mute, and Mic Logic already in place to allow for you to use as it as-is, or add to as needed to suit the needs of the client. Control points within the file have been noted with an additional text box showing their default instance ID tag. These tags can be changed as needed to suit the programmer workflow or standardization.