Tuning an external microphone for Adaptive Voice Amplification — HDL310 system

Learn how to tune an external microphone for Adaptive Voice Amplification with an HDL310 using the tuning controls when using the Nureva^® App.

Before starting

1. Set up the Nureva App to manage the Nureva system.

   • Get started with the Nureva App

2. Confirm the HDL310 system is up to date.

   • Device version 2.3.3591 is required to enable some features.

   • Update HDL310 and HDL410 system firmware

3. Set the HDL310 system as the default audio device.

   • Learn how to set the default audio device

4. Review the external microphone’s user guide.

   • Reviewing the set up instructions for the external microphone will help ensure a successful set up.

Audio jack cabling

An XLR to 3.5 mm TRS adapter cable is required. The cable can be balanced or unbalanced, however the HDL310 connect module only supports mono inputs when used with external microphones. This cable is purchased separately from your audiovisual reseller.

Supported microphone types

Adaptive Voice Amplification is compatible with the following supported external microphone types:

• Lavalier

• Headset

• Earset

• Handheld

• Gooseneck

Connecting the external microphone

Wireless microphone

Preparing the wireless microphone transmitter and receiver in advance helps to ensure the remaining set up goes smoothly.

• Set the group and channel according to the microphone instructions.

• Make sure other nearby wireless microphones are not using the same group and channel.

• Confirm that the batteries in the microphone transmitter are working.

Connecting a wireless microphone

1. Connect the cable to the XLR port on the back of the microphone receiver.

2. Connect the cable to the Aux-in port on the back of the connect module.

Wired microphone

A mixer with XLR inputs and outputs is required when using a wired microphone. Preparing the wired microphone and mixer in advance helps to ensure the remaining set up goes smoothly.

Connecting a wired microphone

1. Connect the XLR cable to the microphone and to the desired input on the mixer.

2. Connect the cable to the XLR output port on the back of the mixer.

3. Connect the cable to the Aux in port on the back of the connect module.

4. Turn off phantom power if the mixer has this feature.

Important: To mute the external microphone follow the instructions in the microphone’s user guide. Most wireless microphone transmitters offer a switch to mute or control the microphone’s transmission. Wired microphones should be muted at the mixer.

Setting the computer’s volume level

The computer’s volume level affects the amplification level of the external microphones. Start with the volume set at a level normally used in the room and adjust accordingly.

Adjust Nureva audio device speaker volume in system settings

Add the external microphone to Nureva App

Add the microphone through the Add Device and External Microphone workflow in the App.

1. Open the Devices menu and press the ⨁ button at the top of the dashboard to add a device.

2. Use the drop down menu to choose External Microphone device type.

3. Press Add device at the bottom of the window.

The remaining settings, such as microphone ducking, aux in port and gain levels should be set during a test call and  by individuals with advanced knowledge of audio engineering and room acoustics.

Removing the external microphone from the Nureva App

Remove the microphone through the Devices menu and remove device workflow in the App.

1. Open the Devices menu and select the external microphone to be removed.

2. Scroll to the bottom of the External microphone window.

3. Press the Remove device button at the bottom of the window.

The external microphone is now removed and Adaptive Voice Amplification will become disabled.

Making adjustments during a test call

Important: Adjusting settings during a test call, with people in the room, simulates a typical meeting and helps ensure optimal performance from the HDL310 and external microphones.

1. Start an audio or video conference using a platform such as Microsoft^® Teams or Zoom.

2. Use the external microphone for a few minutes to test the HDL310 speaker volume.

3. If people in the room find the speakers too loud or too quiet, adjust the HDL310 speaker volume.

4. Do not adjust the gain of the external microphone system.

This goal is to establish a volume level for the room where people in the room are comfortably hearing remote participants as well as media played from the computer during a typical meeting. Please note that if the host computer volume is changed at any time, the Adaptive Voice Amplification settings may also need to change.

If a dedicated in-room computer is not available, use the HDL310 remote control to set the volume. When it is not connected to a computer, the HDL310 connect module saves the volume level.

Using dynamic boost

Dynamic boost is an advanced audio processing feature available for Nureva HDL310 systems. This feature actively adjusts audio signal levels, significantly increasing speaker output to ensure clear sound even in large or noisy settings.

This adjustment can boost speaker output by up to 10 dB, depending on the input signal, ensuring everyone in the room can hear clearly. Dynamic boost effectively amplifies low-level audio signals while managing higher-level inputs to prevent distortion, ensuring a balanced audio experience.

1. Open the Settings menu.

2. Locate Speakers and open the menu.

3. If more speaker volume is required in the room (for audio and video conferences or media play), then choose Dynamic boost.

4. To disable Dynamic boost return the Speakers setting to Default.

Note: Adjusting the Bass and Treble settings for the HDL310 speakers using the Custom settings can affect echo-cancellation performance. It’s recommended these settings are adjusted during a test call.

Microphone ducking

Microphone ducking is a setting that improves the experience for remote participants by preventing dual audio signals when Adaptive Voice Amplification is used. When activated, the HDL310 microphone pickup is muted and only the external microphone picks up the presenter’s voice. Whenever the presenter stops speaking, the HDL310 microphones provide full-room pickup.

1. Open the Devices menu.

2. Select the external microphone to be adjusted.

3. Locate Microphone ducking and slide the toggle to the right to enable.

To disable Microphone ducking, slide the the toggle to the left.

Setting to line level or mic level

Generally, Line level (default setting) will be used with the majority of external microphones.  For entry-level external microphones, the volume may not be loud enough so you may have to set the Aux-in to Mic level. Refer to the external microphone’s user guide for information on the best setting to use.

1. Open the Devices menu.

2. Select the external microphone to be adjusted.

3. Locate Aux in and choose the desired setting.

Tuning Adaptive Voice Amplification

Tuning Adaptive Voice Amplification settings should be performed by individuals with advanced knowledge of audio engineering and room acoustics. This process involves careful calibration of microphone gain, gating, and amplification levels to ensure optimal sound quality and avoid issues such as feedback, distortion, or inconsistent audio pickup.

Important: When tuning Adaptive Voice Amplification, start with the in room gain level of 10 dB and a gate threshold of 64 under the Adaptive Voice Amplification settings.

Gain levels

HDL Speaker: In-room (dB) controls the gain level of the external microphones that is heard from the HDL310 speakers.

• Adjust the gain settings on the external microphone receiver and transmitter to achieve an optimal audio level in the room.

• If there's excessive ringing or feedback, reduce the receiver and transmitter gain and then compensate by increasing the in-room gain levels using the Nureva App.

• If the external microphone signal is too weak, lower the receiver and transmitter gain accordingly and switch the Aux input to Mic level using the Nureva App.

1. Open the Devices menu in the Nureva App.

2. Select the external microphone to be adjusted.

3. Locate Gain levels and HDL Speaker: In-room (dB).

4. Drag the slider to the left to reduce the setting and drag the slider to the right to increase the setting.

If the sound is too loud in the room

• If the volume in the room volume is too loud then lower the receiver or transmitter gain as outlined in the external microphone system’s user guide.

• If adjustments to the external microphone gain changes the volume too drastically, reduce the in-room gain using the Adaptive Voice Amplification settings.

• If Dynamic boost is enabled, lower the transmitter gain or reduce the in-room gain by 5 – 10 dB, assuming the computer system’s volume is set at 80%.

If the sound is too quiet in the room

• If the room volume is too quiet, raise the receiver or transmitter gain as outlined in the external microphone’s user guide.

• If adjustments to the external microphone gain are not sufficient then increase the in-room gain using the Adaptive Voice Amplification settings.

• If increasing the gain on external microphone transmitter causes distortion, lower the transmitter gain and compensate by raising the in-room gain.

Assess the volume for remote participants

Start an audio or video conference and assess the volume for remote participants.

1. Start an audio or video conference using a platform such as Microsoft^® Teams or Zoom.

2. Open the Devices menu in the Nureva App.

3. Select the external microphone to be adjusted.

4. Locate USB: Far end to adjust the far end gain.

   • Drag the slider to the left to reduce far end gain and drag the slider to the right to increase far end gain.

5. Ensure that the the USB: Far end gain level is set at 0 dB before beginning the assessment.

If the far end participants find the volume too loud:

• Lower the gain on the external microphone’s receiver or transmitter as outlined in the external microphone’s user guide.

If the far end participants find the volume too quiet:

• Increase the USB: Far end gain under Adaptive Voice amplification settings.

Gate threshold

Gate threshold (mVrms) sets the minimum volume level required to open the gate, allowing the external microphone to transmit the user's voice.

1. Open the Devices menu in the Nureva App.

2. Select the external microphone to be adjusted.

3. Locate Gain levels and Gate threshold (mVrms).

4. Drag the slider to the left to reduce the setting and drag the slider to the right to increase the setting.

If speech is cutting out

• If speech is cutting out while adjusting the in-room audio, the gate threshold must be specified.

• Set the gate threshold approximately 20 units above the Live ambient levels shown using the Adaptive Voice Amplification settings.

• There should be no talking when ambient sound levels are being observed.

• If the gate threshold is too low the HDL310 microphones will be muted all the time.

Important: When tuning a handheld microphone, if the gate level configuration for the handheld microphone includes nearby voices (within 1 meter), it may open when someone nearby speaks. This can cause the HDL310 microphones to mute intermittently, resulting in choppy or broken audio. Adjusting the gate level to exclude nearby voices will solve this problem.

Finding a balance

When tuning an external microphone for use with the HDL310, it’s important to strike the right balance. If you make changes to the external microphone’s settings, be sure to go back to the Nureva App to check the gate threshold and adjust it as needed. Any change in the external microphone’s signal level can affect when the gate opens. A review of the live ambient levels and gate threshold helps future audio and video conferences go smoothly.

Recommended tuning settings

We’ve documented the recommended starting settings for each supported external microphone type. However, each microphone will still need to be fine-tuned to suit the specific room and environment where it’s being used.

Adaptive Voice Amplification tuning table - dynamic boost enabled

Adaptive Voice Amplification tuning table - dynamic boost disabled

When Adaptive Voice Amplification is idle

At times when Adaptive Voice Amplification is not in use the external microphone’s transmitter and receiver should be turned off. This will prevent unintended audio pick-up and amplification. When wired microphones are not being used the mixer should be turned off prevent unintended audio pick-up and amplification.