What is Live Streaming Audio Lag, or Latency?
Live Streaming audio latency is when your audio is not synchronized with your video. Typical audio latency can be as small as a few hundred milliseconds and fairly negligible or may be thousands of milliseconds and completely sabotage your live stream. Anyone well versed in live streaming is certainly aware of the issue.
What Causes Audio Latency?
If you are looking for a magic bullet, one-stop recipe to eliminate audio latency, have fun looking. There are many factors that contribute to creating audio latency. We have broke down the most notable factors below, in order of MOST IMPORTANT to LEAST IMPORTANT factors;
- Type of Microphone
- Bandwidth or Network Speed
- Machine (Laptop or Desktop) Performance
Audio Latency – Type of Microphone (Digital vs. Analog)
External digital microphones, i.e. microphones you plug into USB, transmit much more data than an analog microphone. We use a Yeti USB stereo microphone simultaneous to an one-channel analog microphone (lavalier or lapel) and there is a HUGE difference in terms of latency. While the one-channel analog microphone performs with absolutely no lag, the digital USB Yeti Microphone will have considerable lag.
If you are wondering, why not simply use a one-channel analog microphone, the quality of the digital microphone is FAR SUPERIOR to the analog, so you are essentially sacrificing latency for quality or vice-versa.
Audio Latency – Bandwidth or Network Speed
The second biggest factor in our research is bandwidth or network speed. Our findings are that between 2-5 Mbps upload speeds, digital USB microphones severely degrade and lag behind by anywhere from 600-2000 Mbps. Between 5-10 Mbps, the digital USB microphone will lag typically behind by 300-600 Mbps (sometimes less) and above 10 Mbps there is very little or negligible lag.
Audio Latency – Machine (Laptop or Desktop) Performance
The last significant factor for latency is machine type. We have not applied any science to these tests or observations but our observations are machines should be quad-core or better, 2.4 GHZ or higher with 8MB of RAM and preferably, at least in our case, Intel and not AMD. We have an AMD5 gaming machine with “souped-up” video adapters, and while this machine is awesome for graphics it does not encode (stream) audio or video very well. This may well be our naivety, our lack of knowledge or hardware or a wrong configuration but it’s not for a lack of looking!
3rd Party Broadcast & Production Software (OBS)
We frequently use OBS, Open Broadcaster Software, for our live streaming and depending on conditions and factors mentioned above, we will run into audio latency and lag issues. We have spent quite a bit of time testing configuration, tactics and techniques to reduce or, better yet, eliminate this issue. We have found an example technique that we use to eliminate latency. Please take 3 minutes to watch the video below and learn how to publish KILLER Facebook Live Streams (or any other live stream) with consistency and no audio lag.