Multiple Devices Configuration

Description/Objective

In this example, we will be connecting multiple mics, cameras, and Tesira devices. Altogether, our hardware will include 26 room microphones, 18 cameras, two Tesira Forte CI's, one remote EX-IO expander, one TCM-1A Beamtracking microphone, and one Extreme X440 AVB switch.

Physical Wiring/Line Diagram

Connect microphones and cameras to the inputs and outputs of the Tesira. Connect the TCM-1A and the Expander to the Extreme switch. Connect the "AVB Only" ports from both Tesira Forte's to the AVB switch as well. A customer may or may not want the Tesira or the Extreme switch on their network. In this example, the Tesira is on the customer's network, but not the Extreme switch. Connect the "Control" ports on the Tesira Forte's to the network.

Tesira Software

Processing Blocks

1. If we've completed our physical connections, open the Tesira software and start building a configuration. Add the following blocks:
   • TesiraFORTE CI block x 2
   • AEC Input Block with 2 channels (the remote expander)
   • AEC Output Block with 2 channels (the remote expander)
   • Parle Microphone Block
   • Parle Processing Block
   • Peak Meter x 7
   • Matrix Mixer with 27 inputs and 24 outputs
   • Uber Filters x 26
2. Connect the blocks as follows:

1. • Connect three peak meters to the Tesira Input blocks and the EX/IO Input block. This will help us to be sure we have the proper levels set on the preamp.
   • Connect the AEC block to the Uber Filter, then the Filter to the Level Block.
   • Connect the Level Block to the Compressor and the second Peak Meter.
   • Connect the Compressor to the Matrix Mixer.
   • Connect output 1 from the mixer to port 1 on the Tesira Output block AND to the third peak meter. This way we can make sure to reach the right audio levels before we send it to the camera.
   • Connect the extra output from the Matrix Mixer to the AEC reference. We will not need to activate the Automatic Echo Cancellation feature in this example. However, Tesira will not allow us to delete the AEC reference block. It also will not compile the configuration if any blocks are not connected (including the AEC reference block.) So use the extra output from the mixer as a "dummy output" channel. Do not send any audio to this channel.

When we're complete, our file should look something like this:

Processing Blocks in Tesira

This section will provide further thought process behind each processing block, and how to adjust settings.

1. Input Preamp: We will not use STM-1’s to power the mics – the Forte will provide phantom power. Enable it here for each mic. The gain control on the input block is our preamp. I find for MX202’s the preamp will usually end up being between 42-48 dB. A preamp is what allows us to boost the audio signal without added noise, so this setting is important. Our goal is for the level of normal speech to show up at or around 0 dB on the peak meter.
2. First Peak Meter: This will help us set our input gain to the proper level. As a default though, it will give us an instantaneous reading, which is much too fast to be helpful to us. Select a time between 250-500 milliseconds and enable the Hold button. When we are testing our input gain, we should aim to be peaking around 0dB, “kissing” the yellow. Loud noises such as a door slamming should peak way in the yellow, but not clip the input (not surpass the red section of the meter.)
3. AEC Block: This block does all the processing for noise reduction in the Forte. If we were going to use AEC in our solution, we would activate the AEC button here. This block also includes general noise reduction capabilities (the Noise Reduction setting). I find that Medium is usually the best option for a room mic.
4. Matrix mixer: This is how we decide where to send the audio signal of the mic(s). On the left the mixer shows the inputs, and on the top it displays the outputs. In this example, since we have one mic and sending it to one camera, we simply enable the matrix box corresponding to input 1 and output 1.
5. Second Peak Meter: Press Enable Hold again on the peak meter at the end of our chain. Since we did not use any processing in this example, the levels of the peak meters should match. When we have more complex solutions, this will help us verify our levels and verify that we have configured the mixer properly.
   • Something to note about the Tesira audio is this: There is an 18 dB difference between the Tesira output block and the Axis camera. We will likely need to raise the output level of the Tesira between 12-18 dB to achieve optimal levels in the Axis camera(s).

EQ and Compression

For information on EQ settings, or click the image below:

For Compression parameters, click the image below: