The working from home thread: tips and advice

For video calls aren't you better with headphones of some sort to eliminate echo?

It depends on whether you're using the same audio device for both the speakers and microphone or not.

There is a discreet circuit in almost all audio hardware that is super cheap to add and has great effect... AEC (Acoustic Echo Cancellation). It's basically a small bypass from the output to the input that negates the signal at a small latency and effectively wipes out echoes.

The dotted line is the magic... that carries the output signal, inverts it, adds a tiny latency, and it's applied to the input which cancels out the echo.

But it only works if you're using the same device for input and output.

So if both your mic and speaker are in your laptop... it works. If both the mic and speaker are driven by an audio interface... it works.

But if you choose an external mic and the internal speakers, or external USB mic and headphone jack speakers... then it doesn't work.

This is why things like Zoom and Google Meet will suggest you to use the same device for both input and output, as then they get the AEC removing echoes and low level feedback for free.

It's also why if you look at something like the Rode NT USB mic http://www.rode.com/microphones/nt-usb you will spot a headphone jack on the side. Now why would a desk mic need a headphone jack? Well... so it can have a signal that can go to external speakers and utilise the AEC chip. So if you buy a mic that has a headphone jack use it... otherwise you need an audio interface like the one I have which you can plug speakers into.

1 Attachment