Audio Interface

The "Record & Replay" module needs to be configured to access this feature.

TimeZero can record audio with the "Record & Replay" module when the "Enable Audio Recording" is selected from the Record & Replay Options. Usually, audio recording is used to record room conversation via microphone or VHF output. TimeZero can use the regular computer audio input, a USB Microphone, or an external multi-channel audio interface.

TimeZero can record one audio channel by using the computer integrated Line Input or Microphone. To enable audio recording, select  "Enable Audio Recording" from the Record & Replay Options:

Multi-Channel Recording

If you want to record more than two channels (up to 4 audio channels), it is highly recommended to use an external multi-channel audio interface with "ASIO" drivers. Make sure to check with the manufacturer that the audio interface includes ASIO support before purchasing the audio interface.

Before connecting the audio interface to the computer via USB, make sure to install the latest ASIO drivers (check the manufacturer website). Once the drivers are installed, connect the interface to the computer and start TimeZero. If the interface is properly recognized, its audio inputs should be available in the list of audio devices:

Please refer to the manufacturer user guide to map channel number with physical connector on the interface.

Connecting a VHF

Using "Line" output of the VHF:

If the VHF has a line output (usually RCA connector), simply purchase an RCA to Jack cable and connect it to the computer or audio interface. Make sure to us a mono cable (one ring on the jack connector):

Note: Usually the computer "Line In" uses a 1/8'' jack and the external audio interface "Line In" uses 1/4'' jack, so make sure to purchase the cable or adapter with correct jack size.

Using "Speaker" or "Hailer" output of the VHF:

If the VHF has only a speaker/hailer output, you CANNOT connect the high power speaker output directly to the computer or to the audio interface! The speaker output is too strong and will overdrive (or destroy!) the computer or audio interface. In that case, a "Speaker Level to Line Converter" (adjustable) must be used in between the VHF speaker output and the computer or audio interface line input:

Note: Make sure that the converter is rated for the output power of the VHF. Most VHF have a 30W or less speaker output, allowing you to use commonly found Speaker to Line converter used in car audio.

Note that most of the line converters offer stereo output to two RCA connectors allowing to connect two VHF (one on the left side and one on the right side).

Once the level is converted to line level (RCA), you can then use an RCA to 1/4'' Jack to connect the converter to the Audio Interface:

Or RCA to 1/8'' jack if you connect the VHF to the Line Input of the computer:

IMPORTANT: Make sure to ONLY use mono 1/4'' or mono 1/8'' jack.

Once the VHF is connected to the computer or audio interface, it is recommended to check and adjust the Audio level. If you use an external USB audio interface, use the LED that are usually available on the interface to adjust the gain of the audio interface and/or the level converter. TimeZero also provides level meter from the list of audio channel that are configured.

Once the gain of every channel has been adjusted, it is highly recommended to adjust the threshold slider just above the background noise. Leave all the audio source connected, but make sure that there are not outputting audio (just background noise). Adjust the slider just above the global meter displayed just above the slider.

Note: The threshold is global to all the audio input.

Audio Playback in TimeZero

To test the playback in TimeZero, make sure that regular speakers are connected to the main audio output of the computer. Adjust the audio output of the computer and make sure you can hear the Windows "chime" when adjusting the volume output (confirming that the speakers are working properly):

IMPORTANT: The audio is always playback from the regular computer output. The audio is not played through the external audio interface unless you change the default playback device from the "Sound" Windows Control Panel.

Open TimeZero and make sure that the Audio recording is enabled from the Record & Replay Options. Select the "Analyze" WorkSpace and click on the "Now" button on the bottom left of the screen. Make sure that the VHF or Audio source is outputting audio during one or two minutes. Click on the "Replay last minute" in TimeZero and confirm that you can hear audio from the computer speakers.