Worship Musician March 2018 | Page 28

FRONT OF HOUSE [ UNDERSTANDING DIRECT BOXES | Kent Morris ] After microphones, direct boxes are the most 3. GOOD DIRECT BOXES ARE WORTH THEIR COST. available. High end passive DIs can run common audio input devices on stage. Though While a $25 DI will function, it will not transfer hundreds of dollars and often boast Jensen seemingly simple, direct boxes are vital to the the true character of a $4000 guitar. Think of brand transformers. Active DIs start around clean transfer of audio from source to system. a direct box like a tire on a car. A Ferrari 488 $100 for decent units and go up from there. Originally termed DI (Direct Injection), direct will simply not perform as designed on $59 Some high-end versions include pass filters boxes usually accept an unbalanced hi-Z signal and tonal compensation. Finally, tube-based from a bass guitar, acoustic pick-up, keyboard, DIs, such as the REDDI, are popular in studios or laptop and convert it to a low impedance balanced signal suitable for a console or stage box. Understanding how they work and when to use each type is a handy skill to possess, so and have some application in live environments, Audio from if given proper care. laptops and other here are some steps toward that goal: media players 1. DIs ARE TYPICALLY USED TO INTERFACE STAGE is notoriously INSTRUMENTS WITH THE SOUND SYSTEM. A standard unbalanced ¼” TS (Tip Sleeve) instrument output will not transmit more than about fifteen feet without succumbing to noise and interference, making the DI a perfect solution since it converts the output into a balanced mic signal able to travel 100’ or more to the console without interference, thanks to unstable. The tiny with that of the instrument. While passive DIs worked with most instruments, the sound of Rhodes electric pianos and single coil basses were altered, leading to the introduction of active DIs with additional circuitry. As its name implies, an active direct box contains electronics to gain and shape the signal, and those circuits and makes it possible to send short-range signals (HDMI, guitar) over distance without on stage while the amp is in the back room. behind it always the stage volume of a cranked tube amp to hum as part of matching the impedance the mixer requires cable. A balun is a balanced/unbalanced device cheap sound card 2. INITIALLY DIRECT BOXES WERE PASSIVE, A transformer inside the DI is responsible for to create what is essentially a really long guitar issue. The SGI uses a transmit (TX) and receive have noise and OPERATE. The Radial SGI (Studio Guitar Interface) is used 3.5mm jack and common mode rejection. MEANING THEY REQUIRE NO EXTERNAL POWER TO 4. CONSIDER REMOTE AND RE-AMPING SITUATIONS. their output. A solid DI designed for stereo line level signals will (RX) module to allow the remote use of a guitar The primary worship application is to remove an unpopulated area. Re-amping is running a signal through an alternative signal chain and can be helpful when trying to recreate Gateway, Bethel, and Hillsong tonality with limited gear. 5. USE A STEREO DIRECT BOX TO FIX MEDIA AUDIO PROBLEMS. Audio from laptops and other media players is notoriously unstable. The tiny 3.5mm jack and cheap sound card behind it always have noise and hum as part of their output. A solid eliminate almost DI designed for stereo line level signals will every issue. to have one on the stage plus one in the tech eliminate almost every issue. It is a good idea booth. need power to operate. While battery power Direct boxes can transfer clean audio from was an option, most current active DIs use 48V phantom power coming down the XLR cable Pep Boys tires. For passive direct boxes, the stage to console and do so with little cost from the console to provide the energy needed. low-cost standard is the Whirlwind IMP2. It has relative to the system. Keep several on hand A general rule of thumb is to use passive DIs a decent transformer to prevent saturation on and remember to use active DIs on passive on active instruments such as keyboards and most instruments and is built tough enough signals and passive DIs on active signals. active DIs on passive instruments such as to survive years on the road. The Radial PRO a P-Bass. series is the most common step-up model with both mono (D1) and stereo (D2) versions 28 March 2018 Kent Morris 35 year veteran of the worship technology arena with a passion for excellence balanced by the knowledge digital is a temporary state. WorshipMusician.com