If your goal is to minimize latency to facilitate live music performance, it’s important to understand that JackTrip is only one piece of the chain.
Video: Understanding latency in JackTrip
We believe JackTrip’s Desktop App is the best piece of its kind, but there are several other pieces that need to work well alongside it. Each piece adds latency, and any weak link can cause you to have a poor experience.
Latency, in the context of audio transmission, refers to the time delay between sending an audio signal from your device to its reception at another endpoint, such as you studio or another participant's device. Minimizing latency is crucial in real-time audio applications like JackTrip, where musicians need to collaborate synchronously.
Whether you decide to use JackTrip or anything else, here are the most important other pieces to consider:
1. Your Internet Connection
Your Internet connection plays one of the biggest roles in determining latency. Fiber Internet connections (specifically FTTx which use cables made out of glass) are by far the best and produce very little latency, typically four to ten times less than any other type of Internet connection.
Although many Internet Service Providers like to use the word “speed,” they almost always are talking about bandwidth and not latency. Quite simply, any Internet connection that plugs into your modem with copper cables (Cable, DSL, etc.) is going to generate a high amount of latency, no matter how many “gigabits” it may be able to carry. If you’d like to learn more about Fiber Internet technology, see The Case for Fiber to the Home, Today: Why Fiber is a Superior Medium for 21st Century Broadband.
Today, about 50% of Americans and 60% of Europeans have access to Fiber Internet. This is about twice what it was just several years ago. Both Internet Service Providers and policymakers are investing heavily into infrastructure to dramatically increase accessibility by 2030. We highly recommend that everyone uses a Fiber Internet connection, wherever they are available. If you don’t have access to Fiber, lobby for modern infrastructure to ensure that you don’t get left behind in the next digital era.
Your Internet Connection can add from 4 to 40 milliseconds of latency. Search here for Fiber Internet providers in your area.
2. Your Physical Location
Distance matters, and even the most optimized setups are limited by the speed of light. Not distance in the sense of how far a crow flies from point A to B, but rather which roads you need to drive along to get there. Like roads, the Internet’s backbone is continuously getting better. Theoretically, musicians on one side of a continent should be able to play live with musicians on the other, but the Internet isn’t that efficient yet. Today, the results will be different for everyone. You just have to try it for yourself to see. That’s why unlimited usage of JackTrip is completely free, with no obligations, for your first 4 weeks.
One thing that makes JackTrip unique is that it uses cloud computing to deploy more functionality closer to the people who are using it. JackTrip uses locations on the Internet designed to minimize your audio’s travel time, often providing faster routes than direct (P2P or “peer to peer”) connections. People who reside within one of these geographical regions are likely to experience the best results.
Your physical location can add from 2 to 100 milliseconds of latency. We’ve seen people successfully play music together on JackTrip across distances of up to 1000 miles, when everyone is using Fiber Internet.
3. Your Audio Interface
The audio chips that most manufacturers bundle inside your computer to check off the “audio” box may be good enough to play an MP3, but they are often not going to cut it for JackTrip. Audio hardware has only gotten fast enough to facilitate live performance within the past few years, and it will take time before this newer technology proliferates throughout the industry. The good news is you can buy high quality USB audio interfaces for around $100 (USD) that produce great results by plugging into your computer.
Windows users must utilize high quality ASIO drivers provided by the manufacturer of their audio interface. These bypass the sound system built into Windows, which is currently incapable of low latency audio. Mac users are likely to see far better results because of the additional investment Apple makes into their hardware, and MacOs’s excellent built-in sound system.
Unfortunately, despite having tested dozens of them, we have so far found no digital headsets (including USB, wireless and gaming headsets) that are capable of providing low latency audio. Only analog headsets will work well.
Your audio interface can add from 5 to over 100 milliseconds of latency.
4. Your Other Gear (No Wireless!)
When it comes to audio latency and quality, your microphone, headphones and home networking all matter. Plug into ethernet and use wired headphones because all wireless technologies (Wi-Fi, 5g, network extenders, wireless headphones, etc.) introduce high latency and jitter, and will not work well. If you are not comfortable with the use of your audio interface and other gear, you will likely struggle.
If you are using a laptop computer, plug into power and make sure that your battery is charged. Some computers will throttle performance severely when running on a low battery (even when plugged in!). This makes it very hard for JackTrip to do its job properly.
Try not to learn too many different things at once. You will save yourself a lot of time and frustration by taking the time to learn how to use all of your analog and digital audio gear (where to plug things in, how to set volume levels, etc.) before you jump into trying out any live collaboration software.
Using Wi-Fi or other wireless technologies can add from 3 to over 100 milliseconds of latency, often with high amounts of jitter that leads to audio glitches and dropouts.
Using JackTrip's Latency Indicators
Each participant's video window has a speedometer icon in the upper-left hand corner. This should always show up when you hover over someone. If it shows up with a red background, even when you are not hovering over someone, it means that their latency is not optimal and you should not expect good results.
Oftentimes, high latency problems can be corrected. Sometimes all it takes are settings changes, plugging in versus using wireless, or installing the right drivers. It may require upgrading your audio interface or Internet connection to get good latency results. JackTrip tries to detect and help you solve the problems when it can. Please also feel free to get help from someone on our team!
The statistics reported only measure the impact of your Internet connection. Your computer, audio interface and drivers add additional latency. If you are using the desktop app (2.0 or later), and the problem is due to your audio interface configuration or drivers, it will provide additional guidance via an “Audio Configuration Warning.” However, it may not be able to detect or represent the impact of using poorly performing audio interfaces.
Try Lower Buffer Sizes
If you have already optimized everything else, and things are working pretty well but you would like to try lowering latency even further, you can try using lower buffer sizes. Our testing suggests that switching buffer sizes from the default of 128 to 64 can help reduce latency by an additional 20-25%.
Before you make this change, please note that it will place higher demands on your computer, Internet router, connection and audio interface. Many of these are not capable of handling it, and only one weak link will cause audio problems. If you experience any problems at all, changing it back to 128 should be your first step before contacting us for support.
For the biggest impact, this needs to be changed in multiple places:
- Your studio's advanced audio settings. Navigate to the "Settings" tab on your studio's dashboard and click on "Make Changes Anyway". Change your buffer size to 64, and we also recommend changing your server type to "JackTrip" (disable Jamulus compatibility). Please note that making these changes will disconnect all participants from any active sessions that you have.
- The advanced settings in the desktop app (for each participant). After opening the desktop app, click the "Settings" button at the bottom and then go to the "Advanced" tab. Change your buffer size to 64. If it changes back to a different number, this means that your audio interface does not allow you to change it via JackTrip. Consult your audio interface's documentation for instructions on how to change it. If you use other software with JackTrip (such as a DAW), you need to ensure that everything is set to the same buffer size (as well as a frequency rate of 48,000 Hz).
It's OK to try just one or the other, or if some people change it in their desktop app and others do not. You should still experience lower latency; however, the best results require changing it everywhere.
Understanding Latency Myths
Despite common misconceptions, some factors do not significantly impact latency:
- 'Latency' vs 'Internet Speed' misconception: It's a commonly used misconception that internet speed (bandwidth) is synonymous with roundtrip latency. While bandwidth measures the volume of data that can be transmitted in a certain time period (e.g. 1 Gbps), latency refers to the time taken for data to travel between two points. To illustrate, think of bandwidth as the width of a pipe, determining how much water (data) can flow through at once, while latency is the time it takes for each drop of water (data) to travel from one end of the pipe to the other. In other words, you don't need super high bandwidth to achieve ultra-low-latency, since other factors are more important.
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Video Transmission: Enabling video alongside audio transmission does not increase latency substantially. The audio roundtrip latency remains mostly consistent regardless of video usage, given sufficient bandwidth.
- Delay perception and the speed of sound vs speed of light: Delays are inherent in real-world acoustic interactions. Even in physical real-world spaces, sound travels at finite speeds, resulting in perceptible delays over distances.
The speed of sound in air is about 330 meters per second, while light travels at a blistering speed of about 300,000 kilometers per second. That's roughly a million times faster! JackTrip harnesses the rapidity of internet communication, which operates at near light speed, to bridge connections between musicians separated by vast distances. Thus, you can achieve lower latencies using JackTrip (and being miles away from each other), than being in the same room, transcending the limitations of geographic proximity.