USB vs MIDI

Friday, 20 December 2019 1:50 pm

With modern modules, there’s a temptation to simply use the included USB hub to link to your computer. But Mario DeCiutiis warns that’s not always the best approach.

When folks decide to use their computer for sounds when using a MIDI controller, the first impulse is to just use a USB to MIDI cable to connect the controller to their computer. Some controllers have a USB port built in, so a simple cable connect is all that's needed. Right? Wrong.

Yes, the cable will connect MIDI from the controller to the computer, but it does NOT address the audio. This means that you must use the audio card built into your computer. The problem with that is that there is unacceptable latency when using the computer’s built-in audio. This is especially true on PCs. Macs are a little better, but if you are a percussionist, any perceived latency will drive you nuts.

Latency is the time it takes the computer to make a sound when you strike a pad on your controller. If you have a PC, and this cable is all you have, downloading ASIO4ALL (for free) at http://www.asio4all.org/ will help lower the latency a bit.

The best solution is for the user to get an Audio/MIDI Interface, or just an audio interface. I always prefer the Audio/MIDI solution because it only takes up one input on your computer. Also, if you are using a USB3 interface or a USB3 hard drive, and you insert the USB 2.0 cable into a shared USB bus, the speed of everything gets reduced to 2.0 speed.

There are many Audio/MIDI interfaces to choose from. Some cost under $100. The higher the sample rate (44.1, 48, 96, 192k), the lower the latency. Of course, the better the interface, the more it costs. Just type in Audio/MIDI interfaces on your browser and you'll see the many options available. Some companies like PreSonus and others include software. This is a real plus if you are just getting started and don't yet have a DAW.

Finally, when you get your interface, make sure that you assign the audio out on your DAW to the interface. You'll also see buffer settings that will have a big effect on the latency. The goal is to get the buffer number as low as possible. You'll know if you've gone too far if you start hearing crackling in the sound. Simply raise the buffer samples.

 When deciding on your sample rate, note that the higher the rate (eg. 192k), the harder your computer has to work. If it starts to overload the CPU, you'll get the crackling as well. The goal is to get the latency value as low as possible by experimenting with the sample and buffer settings.