BMA 360D and TesiraFORTÉ X Voice Lift - quick start guide
This article describes how to program a TesiraFORTÉ X DSP for use with the BMA 360D microphone in a simple voice lift application. Tesira layout configuration files for this application are linked below. Please note that Launch auto-configuration is not supported with the BMA 360D.
The purpose of Voice Lift is to lift the audio heard by listeners at the farthest distance, to the level of an unaided listener sitting closer to the talker. Voice Lift provides a powerful and simple way to drive multiple mix-minus speaker zones, allowing everyone in the room to hear every word.
Prior experience with Tesira system deployment and room acoustics is strongly recommended.
Software and hardware prerequisites
These instructions assume a system comprised of devices similar to that shown below. The BMA 360D can be deployed in systems beyond the scope of this article; for more information, please see the additional resources on Cornerstone. You will require Tesira Software, Biamp BMA Config and Dante Controller (Audinate) to be installed on your PC, and an Ethernet connection to the TesiraFORTÉ X on port 1.
Hardware Placement and Speaker Zoning
Before configuring the software, ensure the physical environment is optimized for voice lift. The relationship between the talker, the microphone, and the loudspeakers is critical.
For the best results, position the BMA 360D so that the primary talkers are within an optimal distance range.
- `1100mm` (approx. 43 inches) is ideal for a standing presenter.
- `1600mm` (approx. 63 inches) is acceptable for seated participants.
- Distances approaching `3000mm` (approx. 118 inches) will significantly reduce the effectiveness of the voice lift.
To prevent feedback, microphones must not face the amplified audio from nearby speakers. Assign the room's speakers to distinct zones.
Configure the system so that the microphone lobes pointing at the presenter feed the loudspeakers farthest away from them.
BMA configuration
When positioning the BMA microphone, it needs to be located in a position to minimize the distance from every talker to the microphone and enable best microphone coverage around the speaker coverage. This will enable focusing the beams on the desired talker locations for both presenter (talker) and participants (listeners) in the conference space. Strategic positioning benefits conferencing and voice lift talkers through to enabling future camera tracking.
Tesira configuration
To ensure the best possible audio for both the local room and the conference UC far-end, you must split the microphone signals into two distinct mix paths. The BMA 360D outputs 12x Dante channels to align with the 12x beams it presents to be used. These are routed using Dante Controller (DC) to the Tesira.
Conferencing Mix is what you would do normally without voice lift. The BMA 360D lobe inputs through the AEC (Acoustic Echo Cancellation) block, into a Gating Auto Mixer, and finally mixed down to your USB Output block for the UC platform.
Voice Lift Mix is a complete split of all audio inputs pre-AEC (before it enters the AEC block) and use this for a separate mix path destined for the local room speakers. This allows for separate EQ for room tuning, customer Auto Mixer settings, selectable routing and cross point levels, speaker processing, and low latency.
Why pre-AEC? AEC processing introduces unavoidable latency. If local voice lift audio passes through AEC, the resulting delay will be heard by the presenter as an echoing effect. Mixing pre-AEC eliminates this latency.
Configure USB Mute Sync to enable BMA 360D LED control. Add a Network Command String block to handle USB mute sync so that muting the room also mutes both the voice lift and conferencing mixes appropriately. Ensure the Network Command String is configured to reach the IP address of the BMA 360D network control interface.
Workflow deploying the Tesira layout
Download the following Tesira layout example: Tesira_BMA_VoiceLift_Cornerstone_12June2026.tmf
- Review the Tesira layout example.
- Set up the network. Verify you can reach the Tesira devices, and BMA microphone using software.
- Using BMA software, set the height and focus beams. Note BMA control IP address. Use this in the Tesira layout BMA network control block.
- Using Tesira software, assign the Tesira equipment table and deploy the layout.
- Using Dante Controller software (DC), route the BMA microphone Dante outputs 1-12 to the Tesira Dante inputs 1-12.
- Verify speaker output using test tone. EQ speaker output. Repeat for each speaker.
- Route the desired microphone beam to a speaker. EQ microphone. Repeat for each microphone beam.
- Use the matrix mixer to trim levels. Test and adjust progressively.
- Make a UC call. Verify microphone audio. EQ microphone. Repeat for each microphone beam.
Optimizing for Low Latency
To ensure the presenter does not hear a distracting delay in their own voice, the latency from the microphone to the speaker must be kept as low as possible.
Tesira software > System > Delay EQ button > open the Delay Equalization Groups. Add a dedicated Delay Equalization Group specifically for your Voice Lift.
Assign your pre-AEC voice lift group to every voice lift output block in the Tesira layout. This enables Tesira to optimize the compiler for this specific path, allowing you to achieve an exceptionally low latency you will see in the Tesira compiler outputs.
Configuring Key DSP Blocks
Several specific DSP blocks should be utilized to maximize gain before feedback and ensure consistent volume levels.
The Advanced Compressor / Limiter is inserted on both mixes. Use the make-up gain settings to carefully balance the levels between soft-spoken and loud talkers. Proper gain structure (unity gain from input to output) is crucial here.
AEC References use a mix-minus referencing for the BMA 360D beams to tighten the sound delivered to the conferencing device. This technique cancels any voice lift that one of the other microphones may hear from the room.
Use a Gating Auto Mixer on both mixes. The conference mix is the default however, for the voice lift mix, the advanced properties have been changed to help control the behavior of the mixer on the direct outputs. Navigate to the advanced settings and adjust the parameters to optimize the gating specifically for the ambient noise floor and ceiling microphone characteristics. The default settings are typically optimized for tabletop microphones.
Frequency Shifter (TesiraFORTÉ X only) has been utilized inserted on the voice lift speaker path. This block slightly shifts the frequency of the audio, breaking the acoustic feedback loop and allowing for higher overall system gain. Enable this last, after speaker and microphone tuning.
Room Tuning and Best Practices
Achieving natural-sounding voice lift requires careful room tuning. Set realistic boundaries. The goal of voice lift is subtle reinforcement, not rock-and-roll concert volumes. If the presenter can just barely perceive the reinforcement when speaking, the level is likely sufficient for listeners at the far end of the room.
Tune the Speakers First: Always equalize and tune the loudspeaker system to the room *before* turning on the microphones. Ensure the speaker response is flat and intelligible.
Tune the Microphones second for Voice Lift, and third for Conferencing. Both mixes will have unique characteristics for every scenario.
Professional Audio Tools: Utilizing a talk box and an audio frequency analyzer will significantly help achieve better results than tuning by ear alone.
DSP Resource Management
Voice lift setups with dynamic tracking microphones require significant DSP processing. Keep the following in mind when designing your system:
Utilizing multiple mix downs, speaker processing, filters, mix-minus routing you will need at least one TesiraFORTÉ X 1600 per BMA microphone and four speaker zones.
If your design requires multiple microphones (e.g., 2x BMA 360D microphones and 8x Speaker Zones), plan to use multiple TesiraFORTÉ X 1600 units (one per microphone)
For larger designs, use a Tesira Server-IO AVB with cards to align with the required AEC channels and processing. You will need to add EX-USB/UBT AVB and 64x64 Dante card, EX-USB/UBT AVB, or alternatively if used with Voltera D amplifiers you can utilize the built in 32x32 Dante as well as AVB natively.
Additional options
If you require additional USB endpoints or Bluetooth, an EX-USB or EX-UBT can be added to this layout.
For more loudspeaker channels, add Tesira PoE amplifiers such as AMP-450P/AMP-450BP or any Voltera D model.