- by George Petersen
in Tips & Tricks
Onstage strings — meaning a real string section — are nothing new to rock shows, although this addition to the current Rush outing is a definite change. Another change for the continuing Clockwork Angels tour (the second leg of which kicked off on April 23, 2013, with Rush delighting a sold-out house of more than 16,000 fans in Austin’s Frank Erwin Center) was the band’s return to a number of markets not visited during the tour’s first leg, which began last September.
At the same time, some things (thankfully) don’t change, with the lineup of vocalist/bassist/keyboardist Geddy Lee, guitarist Alex Lifeson and drummer Neil Peart continuing to churn out their own brand of intelligent, intricate and invigorating hard rock. So far, so good.
» The Problem
But this first time that Rush had a string section might have been fraught with difficulties. More typically, in such instances, the string players are conveniently located off to the side, away from the amps, drum fills and Peart’s elaborate 75-piece drum kit. So when Brad Madix signed on for his fifth full tour as FOH engineer for Rush this past year, he was faced with a sizeable dilemma. Not only would this iconic Canadian prog-rock power trio have a string section, but the players would be performing right on stage with Rush.
“I’ve worked with strings in the past, but it was always either in a very quiet setting with minimal sound reinforcement or the violins were strictly electric,” says Madix. “On the Clockwork Angels tour, the band definitely meant for the strings to be featured and acoustic. The main challenge was fitting pickups to the instruments without tampering with them too much and getting a great sound with maximum isolation — all in a high-gain environment.”
» The Solution
With the strings being placed directly behind the drum kit (see placement in Fig. 1), Madix had to rule out miking the instruments as a section, or even individually. He opted to use bridge-mounted pickups on most of the instruments. “We wanted to avoid any kind of involved install on the instruments, hoping to find a solution that simply clamped on (as opposed to replacing a bridge or gluing something to the instrument). There were a few different solutions available, all of which amounted to some version of a piezoelectric pickup mounted to the instrument in one fashion or another.”
Then came the challenge of impedance matching and preamplification. “That’s when things got a little dicey. All of the piezoelectric pickups are very Hi-Z. In fact, our first choice topped the list at 10-million Ohms! Obviously, we were going to need a DI for these, and it was probably going to have to be an active one, and even then not just any was going to do the trick. When I started digging into which would make the best solution, I was not surprised to find that input impedance specs on DIs are generally a bit lower than what we were going to need. We found preamp solutions, but they offered too many bells and whistles for my taste. We just wanted to get the signal to the consoles in the best possible shape.”
Madix had resigned himself to having something custom made when he sent over a note to Peter Janis, president of Radial Engineering (radialeng.com). “When Brad contacted me, I told him his timing was impeccable,” Janis explains. ”We had been having conversations with a few other acoustic artists and noticed that there was a definite need for a DI that would sound good with piezos.”
The challenge here? “Unless the pickup sees a very high input impedance, it tends to sound peaky and edgy,” says Janis. “We had just finished building a prototype and I sent him the first one to play with. The Radial PZ-DI can be set to 10 Megohms to address this and has a built-in high-pass filter to eliminate resonance, which can cause runaway feedback. After Brad did some tests, he was pleased with the results and we sent them a bunch more. The rest is history in the making.”
The Clockwork Angels string section complement of six violins and two cellos all run through Radial’s newest addition to its line of DI boxes. Other gear on the tour includes a variety of Radial DI models used for keyboards, drum electronics, samplers and guitar effects; as well as the company’s SW8 auto-switcher that allows instant switching to redundant backup systems.
“With the PZ-DI, we were able to integrate multiple piezoelectric devices seamlessly, and with glorious results,” explains Madix. “Anyone who is just plugging a piezoelectric transducer into any random DI and hoping for the best is probably missing out on much better tonality and dynamic range. It’s nice that there are passionate designers and engineers out there paying attention to these details.”