Can MIDI be sent over USB?
What is MIDI?
MIDI stands for Musical Instrument Digital Interface. It is a technical standard protocol that allows electronic musical instruments, computers, tablets, smartphones and other electronic equipment to connect and communicate with each other to exchange musical performance data (Wikipedia, 2022).
The MIDI protocol transmits event messages that specify notation, pitch and velocity, control signals for parameters such as volume, vibrato, audio panning, cues, and clock signals to set tempo. This allows electronic devices to control one another and operate in synchronization. MIDI does not transmit audio signals or digitized sound directly – it only carries musical performance instructions and parameters.
MIDI was first adopted in 1983 and allowed different digital instruments to communicate for the first time. This interoperability unleashed a revolution in music production, composition, performance and recording techniques (MusicRadar, 2012). MIDI remains an essential tool for musicians and audio professionals today.
MIDI Cables vs USB
Traditional MIDI uses 5-pin DIN cables to transmit data between MIDI devices. These cables provide a reliable and low latency connection, but are limited to 31.25 kbit/s bandwidth. As music production setups become more complex, the amount of cables required can be cumbersome.
In contrast, USB provides higher bandwidth up to 480 Mbit/s. This allows for transmission of more simultaneous MIDI messages with lower latency. USB cables are also more readily available as standard printer or device cables. However, power supply and driver support can be an issue with some USB MIDI interfaces.
Overall, USB offers practical advantages for connecting multiple MIDI devices. But traditional 5-pin DIN retains advantages for latency-critical applications. Many modern MIDI interfaces provide both options.
MIDI Over USB Specifications
The MIDI over USB specification was first introduced in 2000 to allow MIDI data to be transmitted over USB cables and connections. In 1999, the USB Implementers Forum published the Universal Serial Bus Device Class Definition for MIDI Devices, which defined how MIDI data could be sent over USB using the USB-MIDI protocol.
This initial 1.0 version of the USB-MIDI specification allowed for basic transmission of MIDI messages between USB-connected devices. It defined standard USB descriptors required for identifying MIDI devices, as well as how MIDI data packets should be formatted and transmitted over USB.
An updated 2.0 version of the USB-MIDI specification was later published in 2019. This introduced support for MIDI 2.0 features, while retaining backwards compatibility with traditional MIDI 1.0 gear. The MIDI 2.0 protocol brought increased resolution, more expressiveness, and two-way communication capabilities compared to MIDI 1.0.
Thanks to the USB-MIDI protocol, MIDI devices can now interconnect and communicate MIDI data over standard USB cables and connections. This allows for greater flexibility in studio setups and live performance rigs using MIDI gear.
USB MIDI Interfaces
USB MIDI interfaces allow musicians and producers to connect MIDI devices like keyboards, drum machines, and synthesizers to their computer via USB.
Devices like audio interfaces allow MIDI connectivity over USB by including MIDI inputs and outputs. They convert the MIDI data coming from the instrument into a format that can be transmitted over USB to the computer. They also convert MIDI data coming from the computer over USB back into the standard MIDI format so it can be understood by MIDI devices.
There are many benefits to using a USB MIDI interface. Since the MIDI data gets converted to USB, you can use a simple USB cable to connect rather than bulky 5-pin MIDI cables. USB also provides higher bandwidth and speed compared to traditional MIDI cables. Additionally, USB power allows many interfaces to operate without an external power supply.
Overall, USB MIDI interfaces make it easy to integrate hardware MIDI instruments into a computer studio setup. They provide a straightforward way to get MIDI in and out of any computer with a USB port.
Driver Requirements
In order for MIDI data to be sent successfully over USB, the proper drivers may need to be installed on the computer. Many MIDI keyboards and controllers require a dedicated driver from the manufacturer in order to function over USB.
For example, companies like Yamaha, Korg, and others provide USB-MIDI drivers for their products to work with Windows and Mac operating systems. These drivers allow the device to connect via USB and transmit MIDI data reliably.
However, some computers and operating systems have native support for USB-MIDI connectivity. For example, Mac OS X has a built-in USB-MIDI driver that allows class-compliant MIDI devices to connect without any additional driver installation. And Windows 10 and 11 also include native USB-MIDI support, which can potentially avoid the need for a separate driver if the device is class-compliant.
So in summary, dedicated MIDI drivers may be required for some USB devices and set-ups, but can potentially be avoided if the computer OS and MIDI device have native support for class-compliant USB-MIDI connectivity.
Applications
One of the major applications for using MIDI over USB is to connect keyboards, synthesizers, and DAWs (digital audio workstations) via a USB-MIDI interface instead of traditional 5-pin MIDI cables and interfaces (Amazon.com: Midi Keyboard). This allows musicians to simplify their cabling and setup for live performances or studio sessions by reducing the number of required cables and interfaces.
With a USB-MIDI interface like the M-Audio Uno (Guitar Center MIDI Keyboard Controllers), a musician can connect their MIDI keyboard controller directly to their laptop over USB, rather than running a separate MIDI cable. The MIDI data is then sent over USB to music production software like Ableton Live, Logic Pro, etc. This reduces cable clutter and makes setting up and connecting devices quicker and easier, an important factor for live performances.
In the studio, producers can connect their MIDI keyboard, drum machines, synthesizers and other gear to their computer via USB-MIDI interfaces. This allows them to sequence music and pass MIDI data between devices and software over a simple USB connection, rather than dealing with multiple MIDI cables and interfaces between each piece of gear.
Latency Considerations
The nature of USB may introduce some latency and jitter when working with MIDI. According to the KVRAudio Forum, this added latency is usually in the range of 2-10 ms when using MIDI over USB. For live playing, even small amounts of latency can make performing difficult. Fast response is critical when playing a MIDI keyboard live.
There are some steps you can take to optimize your system and reduce latency when using MIDI over USB. Making sure you have the latest drivers for your USB interface and setting your audio buffer size appropriately can help. Some higher-end interfaces also have direct monitoring options to bypass latency. Using an optimized OS like Windows 10 or macOS rather than an older OS can also improve MIDI timing and response.
While impossible to eliminate entirely, careful setup of your software and hardware can minimize latency issues when using MIDI over USB in live performance situations.
Caveats
While sending MIDI over USB offers many advantages, there are some limitations to be aware of. Not all MIDI devices actually support USB-MIDI connectivity. This is especially true for older hardware synths and MIDI gear that predate the development of the USB-MIDI specification. Budget entry-level devices may also lack good USB-MIDI implementation due to cost-cutting measures.
For example, the ModWiggler forums discuss how many older synths like the Minimoog only have 5-pin DIN MIDI I/O and cannot connect directly over USB without an interface. So before purchasing a USB-MIDI device, it’s important to check compatibility and ensure it will work with your existing gear.
Tips for Using MIDI over USB
When setting up your MIDI over USB connection, there are a few tips to keep in mind for optimal performance:
Use high-quality MIDI cables. Poorly shielded cables can introduce interference and latency. Invest in a solid MIDI cable designed for USB connections.
Install any required manufacturer drivers for your MIDI interface or controller. Generic plug-and-play drivers may not provide the best performance. Download ASIO drivers or other optimized software to reduce latency.
Adjust OS and DAW settings to prioritize latency. Reduce buffer sizes in your audio interface control panel and DAW preferences. On Windows, disable power management for USB ports in Device Manager. Test different Sample Rate settings to find the best balance of latency and stability.
The Future of MIDI over USB
As USB ports become nearly ubiquitous, the adoption of USB-MIDI continues to grow. Musicians are finding the convenience and reliability of USB-MIDI to their liking, leading more MIDI device manufacturers to include USB connectivity in their products.
Looking ahead, increased adoption is expected to drive further improvements. Manufacturers will continue working to reduce latency and improve compatibility across operating systems and DAWs. Some options like class compliant devices avoid the need for proprietary drivers altogether, making setup easier and improving plug-and-play functionality across devices.
With wider adoption, USB is poised to become an even more appealing option for MIDI connectivity. Lower latency and wider compatibility across devices and platforms will likely make USB-MIDI the preferred method for many musicians and studios moving forward.
As stated on TalkBass, “USB ports become nearly ubiquitous, the adoption of USB-MIDI continues to grow.” This ease of connectivity makes it a convenient option for musicians.
