Nureva® audio conferencing systems are designed to provide high-quality microphone pickup and speaker output in a variety of room types. Each conferencing system is designed for a specified maximum room size. However, there are two scenarios where one might wish to connect external speakers:
- There is already an installed speaker system in the room that’s preferred for audio conferencing
- In rooms with high background noise and/or poor acoustics, extra speaker output may be required
NOTE: If speaker output is a concern, the following support articles may also be helpful:
- Bass & treble settings for speaker volume optimization
- Adjusting system settings for desired speaker volume
Connecting external speakers
The HDL300, Dual HDL300, HDL310 and HDL410 audio conferencing systems can be used with external speakers. To connect external speakers, follow these steps:
1. Connect the external speaker system to the auxiliary output port on the connect module
- 3.5 mm stereo jack, line-level
2. Set the auxiliary output port to the speaker out mode in Nureva Console
- See our articles about using auxiliary ports for more details
- The speaker out mode routes the speaker signal to the external speakers and disables the Nureva device’s built-in speakers
- Since there is only one auxiliary output port, the UC&C connection (both microphone and speaker) must be USB when the speaker out mode is used
- The output for the external speakers will be monaural (mono), despite any settings in Nureva Console or the source of the signal
- Perform a fast calibration with the Nureva audio conferencing system to configure the new setup
Echo cancellation
With external speakers connected to the auxiliary output port and the speaker out mode selected in Nureva Console, the Nureva device will echo-cancel the speaker signal to prevent remote participants from hearing an echo when they speak. However, the echo-canceling function of Nureva audio systems is optimized for the original speakers, so performance with external speakers may vary.
Considerations when using external speakers
Fixed gain
The amplifier should have a fixed gain. If the amplifier can vary the gain, then the gain should be set to one value and not changed (especially when using the amplifier). Varying the gain using the external hardware amplifier could cause the calibration settings to be invalid and reduce system performance. The speaker volume should only be adjusted within the application software or operating system.
Flat gain
The amplifier and speaker should have a reasonably flat gain over the voice band frequency (300 Hz to 7 kHz) for the best performance. Equalizers or speakers that result in unlevel gain will cause degradation in the echo cancellation performance.
Avoid bass-boosting
Avoid any bass-boosting amplification (in the 50 Hz to 300 Hz range), powerful bass speakers or equalization schemes, which will cause an uneven frequency response.
Locating the external speakers
The external speakers should not be installed close to the microphone and speaker bar, nor should they be pointed in its direction. Direct coupling from the speakers to the microphones will cause issues with echo cancellation.
Using external speakers with HDL410
When first installed, the HDL410 runs through an extended calibration sequence that configures the echo canceler and determines the relative geometric location of each microphone and speaker bar. The calibration routine must be run through the built-in HDL410 speakers.
- Perform a fast calibration on the HDL410 after it is installed but before connecting external speakers or setting the auxiliary output port to the speaker out mode
- Do not perform a fast calibration after external speakers have been connected and the auxiliary output port has been set to the speaker out mode
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These considerations only apply to HDL410 firmware version 1.3.222752 or earlier