Latency is one of the most important aspects of online music performance, and also perhaps the least understood. We are writing a series of blog posts to shed more light on the concept and nuances of latency. In this part 4 of 10 on latency (part 1 starts here), we discuss audio processing latency – i.e. the time it takes to convert analog audio from an instrument or voice to digital audio a computer can use, and then to convert digital back to analog audio for another musician in your session to hear (highlighted in the latency pipeline below with a white background and blue text).
Audio Processing (Analog to Digital)
When you sing or play an instrument, it creates sound waves that travel through the air. When these sound waves reach the ears of another musician, they hear the sound you’re making. This kind of sound is called analog audio, and this is how traditional in-person music sessions work.
To play in online sessions, JamKazam must transmit your audio over the Internet to other musicians in your session. To transmit your audio, your analog audio must be converted into digital audio that a computer can understand and process. A hardware product called an “audio interface” is the right tool for this job. Below is a picture of a typical audio interface.
To use an audio interface, you connect your instrument and/or a microphone to the audio interface, and connect the audio interface to your computer. As you play or sing, the audio interface converts the analog audio from your music into digital audio, and the JamKazam application sends your digital audio across the Internet to the other musicians in your session. This is shown in the white box on the far left of the diagram above.
Audio Processing (Digital to Analog)
When your digital audio reaches the computer of another musician in your session, their audio interface receives your digital audio, converts it back to analog audio, and plays it to that musician through the headphones they have plugged into their audio interface. This is shown in the white box on the far right of the diagram above.
Audio Interface Speed & Cost
For musicians new to the tech world, it can be a little confusing to know how to choose the right audio interface. To help, JamKazam has researched a variety of audio interfaces, and we have published our findings in two help articles: Audio Interfaces for Mac and Audio Interfaces for Windows. You’ll find in these articles that you can get a fast audio interface that produces very high-quality audio in a price range from $100 to $200. When we say fast, these interfaces typically handle analog-to-digital plus digital-to-analog (i.e. the conversions required on both ends of the diagram above) in a range from 4 to 8 milliseconds (a millisecond is one thousandth of one second). This averages out to 6 milliseconds, and this is the number we’ve used in the end-to-end latency diagram above, with 3 milliseconds allocated to each end of the diagram.
What About Built-In Microphones & Headphone Jacks on Computers?
We are sometimes asked if you can just use the built-in microphone and headphone jack on your laptop for JamKazam audio. It would be great if this worked – because it’s free. However, there are two problems with this approach. First, the audio quality you’ll get from the built-in microphone is pretty bad, so it harms the experience of playing together in sessions. If you use an audio interface, it sounds like you’re sitting in a recording studio, and you’ll be amazed at the sound quality. Second, and perhaps even more important, the latency (lag) from using the built-in microphone on your computer is so high that it will prevent you from being able to play in sync with others. The audio processing latency on a Mac using the built-in mic and headphones is currently 52 milliseconds (compared to about 6 milliseconds on average for an inexpensive audio interface). On a Windows computer, it varies more, but is typically over 20 milliseconds, which is still much too high.
How Can I Minimize My Audio Processing Latency?
To crank your audio processing latency down to a minimum while maintaining high-quality audio, you’ll want to get your audio interface settings just right in the JamKazam app.To do this, we recommend you review and follow our instructions for audio interface set up for Mac computers or for Windows computers. We have published detailed setup walkthroughs for the a number of specific, popular audio interface products, as well as a more generalized guide for other interfaces.
The Next Article in the Series
Our next article – part 5 in our series on latency – dives deeper into something called “jitter” and how it affects latency. We’ll add a link to this article when it’s published.
Curious To See How This Works?
While we understand the natural skepticism many musicians feel about the ability to play together live in sync in online sessions, we’d point out that musicians have now played in more than 3 million online sessions on JamKazam. You can check out a small handful of sample performances in this YouTube video, with all the musicians playing on JamKazam from their homes over the Internet. Or see a ton more recorded JamKazam performances on our YouTube channel. If you’re interested in trying it out, you can do so risk-free by going to https://www.jamkazam.com and signing up for a free account. We have a support team that can help you get set up and playing online successfully in private sessions with your band or in open/public sessions with other musicians if you’re not in a band.