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 7 of 10 on latency (part 1 starts here), we discuss the specific things you can do to minimize the latency (lag) you hear and feel in online sessions when playing music with others live and in sync from home over the Internet.
Quick Reminder on Latency & Its Sources
Latency – in the context of playing music live online with others – is the time it takes for the audio from your instrument or voice to reach the ears of another musician in your session. If latency gets too high, it becomes difficult or impossible to play in sync with each other. There are three main sources of latency in online music sessions: audio processing, internet transit, and the jitter queue. We’ll review each of these below, and explain what you can do to keep your latency as low as possible, so that you can have the tightest and most enjoyable JamKazam sessions possible.
Audio Processing Latency
Audio processing latency is the time required for your gear to translate the analog audio from your instrument and/or voice into digital audio your computer can understand and process, plus the time required for another musician’s gear to translate the digital audio their computer receives back into analog audio and play that analog audio out through headphones they can hear. To minimize audio processing latency, you should take the following steps:
- Use an Audio Interface with a Good Driver – We often get asked by users if they can just use the built-in mic and speakers on their computer to play in JamKazam sessions. The short answer is “no” – because your audio processing latency will be so high that you won’t be able to have successful, enjoyable sessions. You need to use an audio interface, which is a small piece of hardware that converts analog to digital audio (and vice versa) very fast with very high audio quality. These products are typically used for home recording, and JamKazam extends their use to online music sessions. You can buy a very good interface typically in the $100 to $200 price range. Even when you buy an interface, not all interfaces are made equal. The best interfaces have great “drivers”. A driver is a piece of software the interface manufacturer builds specifically for their hardware product, and it controls that hardware. If you use a Windows computer, you should be sure your interface has an “ASIO driver” that is built specifically for that interface by its vendor. On Mac computers, many audio interfaces “just work” without a driver, but the best interfaces have a driver that will significantly reduce audio processing latency beyond the “plug-and-play” simplest use case. We know this all gets pretty complicated for a normal human being to follow, so we have run tests on a bunch of popular audio interfaces, and you can check what we found and what we recommend in audio interfaces for Windows and audio interfaces for Macs.
- Set Your Audio Sample Rate to 48kHz – This is another complicated/technical topic (sorry), but we’ll do our best to communicate is simply. To convert your analog audio to digital, your computer slices up your analog audio into pieces, and converts each piece into digital form. Your computer can do this at different speeds, which are called sample rates. Windows computers often run these conversions at 48kHz, which is 48000 samples per second. Macs often run these conversions at 44.1kHz. Which is better? Doesn’t really matter. What does matter is that JamKazam uses a technology called “Opus” to process digital audio really fast while maintaining high audio quality. The Opus technology runs at 48kHz, and we can’t change that. This means that if your computer is processing audio at 48kHz, it will plug straight into Opus at the same speed. But if your computer is processing audio at 44.1kHz, JamKazam must translate it into 48kHz before handing it off to Opus. And that will translate into higher processing power usage on your computer and higher latency. As a result, we recommend that you set your computer to process audio on the audio interface you are using with JamKazam to 48kHz. To understand how to set your audio sample rate to 48kHz, read our help article on this topic.
- Set Your Buffer Size & Frame Size Low – Audio interfaces on Windows will let you adjust your latency settings, using a setting typically called “buffer size” or “sample size”. JamKazam also offers its own “frame size” control that affects latency. Step 2 of the gear setup wizard in our app is where you adjust these settings that affect your audio processing latency. As a general rule, you want to set your buffer size as low as you can, provided that audio quality remains high. If you set your buffer size too low for your computer and audio interface to process it reliably, you’ll end up hearing audio quality glitches, and you’ll need to adjust the buffer size up and accept a bit more latency. If you have a modern and powerful computer and an audio interface with a good quality driver, you can usually set the buffer size to its lowest setting, and set your JamKazam frame size to either 2ms or 1ms. If your computer is older and less powerful, you likely want to set your JamKazam frame size to 2ms or 2.5ms, and adjust your audio interface buffer size up one or two notches from the lowest value. Note that on Macs, you rarely have the option to set a buffer size on your interface, and can only adjust the JamKazam frame size. For Windows computers (that offer more customizability), we recommend you review our help article on adjusting these settings when setting up and configuring your audio interface for JamKazam in step 2 of the wizard.
Internet Latency
Internet latency is the time it takes for your audio data to move across the Internet from you to other musicians in your online music session. There is really nothing you can do to improve or lower Internet latency – but JamKazam can and does. JamKazam is the only online music performance platform that has implemented both peer-to-peer (p2p) and server-based Internet connection technologies, and we automatically select and use the best tech and “path” to get your audio data across the Internet, resulting in the lowest possible Internet latency. You can learn more about JamKazam’s unique advantages in minimizing Internet latency in this article.
Jitter Queue Latency
When your audio data is sent across the Internet from you to other musicians in your online session, it’s not a perfectly reliable system. Your data can get lost or delayed, just like mailing packages in the real world. When this happens, it creates problems like greater latency, plus pops, scratches, and other annoying and distracting audio artifacts. To minimize these kinds of problems, the computers on both ends of a connection between each pair of musicians use a “jitter queue”. The longer this queue is, the more it can absorb delayed and lost data, protecting the audio quality in your session. But the longer the queue, the higher the latency in your session.
JamKazam invented and patented a jitter queue algorithm to deal with the challenges of online music performance over the Internet, and our unique technology does the best possible job of minimizing latency from the jitter queue, while optimizing the audio quality in your online session. While this unique invention makes a big difference, there are also two things you can do to help in keeping your jitter queue latency minimized:
- Use Ethernet – You should definitely connect your computer to your home router using an Ethernet cable rather than using a standard WiFi connection. We often have JamKazam users say “but I have tons of bandwidth”. Bandwidth is not the issue. To keep latency minimized, JamKazam breaks your audio up into “packets” – think of sugar packets – and sends your audio in chunks in these packets. The smaller the packets, the lower your latency. Your computer sends 400 packets per second from you to each other musician in your session, and it receives 400 packets per second from each other musician in your session. When you’re browsing web pages and sending email messages, the packet sizes are much larger because it doesn’t matter. WiFi routers are not good at reliably handling the very high packet rates required to deliver ultra low latency online music performance. JamKazam can’t change the WiFi routers built by router makers. What we can do is recommend that you connect your computer to your router using an Ethernet cable. When you do this, you will get perfectly reliable send and receive times for each packet. The Internet will still introduce some variability, but your router will not. To understand how to connect your computer to your home router using Ethernet, read our help article on this topic.
- Reboot Your Router – Routers are effectively just special-purpose computers that do a specific thing very well, with that thing being send/receive of data over the Internet. You’ve likely noticed that the longer you run your computer without a reboot (closing it into sleep mode at night doesn’t count), the more likely your computer is to start glitching in different ways, and sometimes it will eventually just fail and reboot itself. Routers are no different. They are running and working constantly, and a variety of little bugs are happening all the while, which builds up over time to create issues that you can’t see, but are nonetheless very real. We recommend that you reboot your router once per week to keep it fresh, and keep it performing at a high level. To do this, you can simply pull the power cord out of your router, wait about 10 seconds, and then plug it back in. The router will reboot and will start working again, typically in 2-3 minutes, and you can get back to doing your thing.
The Next Article in the Series
Our next article – part 8 in our series on latency – discusses how our distributed real-time metronome can help you play successfully in online sessions, even when latency is higher than ideal. 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 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.