External iSight microphone audio not working

firewiremicrophonethunderboltwebcam

I'm using a 2003-era external iSight "Autofocus Video Camera + Noise Suppression Microphone" with an Apple Cinema Display and USB-C MacBook Pro running macOS 10.15.

It's connected via a long succession of dongles:

iSight > FireWire 400 > Apple Cinema Display > FireWire 800 > Thunderbolt 2 > Thunderbolt 3

It still works great for video, if a bit low resolution, and you can't beat the design:

external iSight camera

However, the iSight camera's microphone does not appear to be working. People cannot hear me when my laptop is in clamshell mode, despite being on video via the external iSight.

In System Preferences > Sound > Input I only see "MacBook Pro Microphone":

Sound Input

System Information shows a FireWire iSight device, as well as an "Unknown Device". When I unplug the FireWire cable/dongle, both devices disappear.

System Information

This iSight is running the 1.0.2 firmware; I'll try to update it with 1.0.3 and test:

Why isn't the iSight mic working? How can I use an external iSight as an audio/video webcam in modern versions of macOS?


Related threads that seem to be experiencing the same issue:

Best Answer

The FireWire iSight audio driver has been omitted from recent macOS releases.

A Mac Rumors contributor has posted a download of the driver from his backup.

Download iSightAudio.driver there, or find the same driver from your own backup.

Place the file in /Library/Audio/Plug-Ins/HAL/

In case there were any other inconsistencies from the original I used a copy from a backup of OS X 10.13. A Finder copy and authentication worked without any permissions issues.

This worked for me on Catalina 10.15.6 on a 4,1->5,1 cMP.