DI Boxes: Yourself Started

If you’ve spent any amount of time in recording or watching studio recording breakdowns, you’ve likely heard the term “DI” or “DI box” thrown around quite often. It’s so commonplace that often it’s accompanied with little-to-no explanation.

What is a DI Box?

DI boxes, or “DI’s” (standing for Direct Inject) are primarily known for use in guitar and bass applications in the studio. However, their function is to correct mismatched impedance signals between instruments and equipment. For example, guitars have a high impedance, unbalanced output that is prone to pick up noise and degrade signal over longer distances. A DI box will convert that signal to a low impedance, balanced signal that will be compatible with outboard equipment and reduce noise for longer runs.

What is Impedance?

In simple terms, impedance is the opposition of a circuit to electrical current, or how much the circuit impedes the electrical flow. Unbalanced signals, like those in a guitar’s output jack, would have higher impedance and thus need to be converted for use in microphone preamps or mixers without picking up a lot of undesirable noise.

High-Z vs Low-Z

“Z” is the letter and mathematical value given for impedance. When you see “High-Z” or “Low-Z” labeled on an input or output, it’s telling you the type of impedance signal coming from that respective input or output. The Hosa DIB443 Sidekick Passive DI Box, for example, has a switch on one side for you to select an instrument