Ely, Minn. â€“ June 8, 2011: On one frigid afternoon this past February, a crew from Classical Minnesota Public Radio (MPR) and the A cappella vocal group, Cantus, MPRâ€™s 2010-2011 Artist-in-Residence, took a three-minute pitch black ride down to the 27th level of the Soudan Underground Mines to record a performance 2,341 feet below the surface. This audio and video venture -- which highlights the most recent installment in Classical MPRâ€™s Sonic Architecture series -- relied on a pair of Sennheiser MKH 800s and Neumann KM 140 microphones to capture the performance and the natural acoustics of the cave.
The performance, which was produced into a video and radio piece using DTS Neural Sound, presented several challenges for Rob Byers, technical director at MPR. Byers had to select a range of gear that would perform in an unorthodox â€œone-takeâ€? environment. â€œThere
was no room for mistakes -- we had to get in, record and get out,â€? he said.
The chosen microphones would need to be able to withstand cruel and extreme temperature and humidity changes -- from below zero and incredibly dry outside, to a moist and damp 52-degree indoor environment. Based on his previous experience both on location and in the studio, Byers chose the Sennheiser MKH 800s and Neumann KM 140s.
"We use the MKH 800s because of their high performance in a variety of locations," Byers said. "I felt confident they would deliver in this unique environment, and I was not disappointed."
Thirteen Men and Four Mics in a Cave
Once deep into the subterranean, Byers and his ensemble tried to mix up their recording set-ups as much as possible. In one particular set up, Cantus, the Minneapolis-based nine-member male vocal A cappella ensemble, stood in a oval shape with Byers placing mics inside the oval to capture both the front and rear of the group for the surround recording. He set the pair of MKH 800s twins in omni, using Sennheiser MZS 80 shock mounts to position them 12 feet high on a pole stand and long meter bar. The Neumann KM 140s were each placed on separate stands in an ORTF array, approximately 12 feet high and three feet apart.
"The Sonic Architecture series is all about capturing the natural sound of the space, and the Sennheiser MKH 800s and Neumann 140s allowed us to accomplish just that."
Please visit the Classical Minnesota Public Radio Page to view the video featuring the Cantus performance inside the Soudan Underground Minds.