Arri Alexa Audio Settings
Press the AUDIO button on the HOME screen to open the AUDIO screen. This screen shows the ALEXA’s two audio channel levels. The audio levels are displayed from -45 dBFS to 0 dBFS.
Note: No audio meters are displayed on the HOME screen or AUDIO screen when audio is set to Off or audio is disabled. Audio is disabled when the sensor frame rate does not match the project frame rate. In this case, no audio is transmitted via HD-SDI.
Light blue markers show reference levels of -20, -18 and -9 dB FS. Red markers at levels -1 and 0 dBFS warn of clipping. With a proper audio signal levels, the red markers should almost never be visible.
Gain can be applied to the audio channels by turning the jogwheel to set both channels, or by pressing the CH 1+, CH 1-, CH 2+ and CH 2- buttons. The amount of gain applied by the camera is indicated next to the levels as light gray numbers.
Note: When adjusting audio input levels, a "clicking" noise can be heard on audio outputs. Adjustment of audio levels therefore is disabled during recording.
Press the OPTIONS button to open the AUDIO IN>OPTIONS screen and set audio parameters.
Turns audio recording On or Off. If audio recording is switched off, no audio is recorded internally, the HD-SDI contains no audio and the Audio out is muted.
Channel 1 level
Manual allows the user to manually apply gain to the input signal on channel 1 to reach a correct level. Unity matches a 4 dBu input signal to -20 dBFS. This setting leaves enough headroom for recording and avoids audio clipping. When Unity is selected, audio levels cannot be adjusted by the user.
Channel 2 level
Manual allows the user to manually apply gain to the input signal on channel 2 to reach a correct level. Unity matches a 4 dBu input signal to -20 dBFS. This setting leaves enough headroom for recording and avoids audio clipping. When Unity is selected, audio levels cannot be adjusted by the user.
Channel 1 source
Select the left or right input signal as the source for Channel 1.
Channel 2 source
Select the left or right input signal as the source for Channel 2.
Enter a name for the sound roll (also known as Tape in the menus of some recorders) of an external audio recorder, for easier sound synching in post-production. The name will be written to the FCP XML file and the Avid Log Exchange (ALE) file on the recording media.
Audio Output Settings
Press the AUDIO OUT button to open the AUDIO OUT>OPTIONS screen where the global volume for both Audio out channels can be adjusted. The OPTIONS button opens a list of AUDIO OUT options.
Sets which channel is routed to the left output.
Sets which channel is routed to the right output.
Audio out level
Set the level of the audio out channels manually, or set it to fix the maximum output.
Note: These settings do not influence the audio signal embedded in the HD-SDI connectors or recorded in QuickTime clips. They only affect the AUDIO OUT connector.
Note: ALEXA automatically determines the internal signal run time and matches audio and images so they are always in sync. When changing sensor fps or project fps, it may take up to 2 seconds for the camera to resync image and audio signals.