Cumulus Propels Sports Radio Into 5.1 Era

Cumulus Media seems to want to do for 5.1-surround audio on radio what ESPN has done for it on television. The nation’s second-largest owner and operator of AM and FM radio stations (behind Clear Channel), with 570 stations in 150 markets, has taken two major-league teams to the multichannel-audio level.

During the 2011 MLB season, Cumulus’s WNNX-FM Atlanta broadcast Braves games, the first ever in surround. More recently, the company’s Kansas City broadcast outlets were able to translate that experience to several NFL Chiefs games on radio. There are plans to do the Braves’ 2012 season in surround, and station technical execs are considering migrating the idea to the NBA, possibly before the end of this season.

Calling it “the standard for the next-generation radio-broadcasting enterprise,” Cumulus SVP of Engineering Gary Kline says surround on the radio brings another dimension to the fan experience: “You hear it differently in surround. It’s a bigger sound picture on radio. The reaction we’ve gotten has been great.”

The Braves games in surround followed a rebuild of the broadcast facilities at Turner Field shortly after Cumulus and Dickey Broadcasting’s 680 the Fan (WCNN) AM station acquired rights to the games in 2009, which took them to stereo, says Kline, who has been broadcasting sports on radio for 20 years. From there, it was a short leap to surround, using DTS Neural Surround gear built by DTS licensee DaySequerra.

According to Marc Lehmuth, manager of engineering for Cumulus, the surround field is configured using the stereo-effects mix from the remote trucks at Turner Field as the front left-right sources. A pair of Sennheiser ME 66 shotgun microphones located on either side of the broadcast box and aimed downward in a near-coincident pair for crowd and bat sounds creates the rear left and right channels. All announce and other mono sources are automatically routed down the center channel, and the DTS system also creates an LF channel for the .1. The entire array is then routed via T1 line to the main broadcast center at Turner Sports for downmixing.

Kline says that this configuration translated well to football for the Chiefs games, with some adjustments for field dimensions and microphone placement. In Kansas City, the DTS Neural Surround gear is integrated both on-site at Arrowhead Stadium and with the Chiefs Radio Network mobile package. The DTS-based setup allows the audio team to broadcast 5.1 surround sound over a stereo transmission path, using the stereo format at the highest resolution possible. The broadcast audio is watermarked, allowing DTS-enabled receivers to decode it into surround but preserving the discrete left-right signal for FM stereo receivers, which also preserves mono reproduction.

Initial testing for this new frontier of sports radio was an interesting proposition. Kline and Lehmuth drove around Melbourne, FL, last March, listening to the Braves’ spring-training games through a DTS-enabled car radio. Kline says the potential problems that they had anticipated as collateral to the move to 5.1 — phase concerns between channels, mono-compatibility issues, artifacts in the MLB streaming versions of the games — never materialized.

“A big concern was frequency problems that might have interfered with the sound effects, like the crack of the bat,” says Kline. “But those didn’t happen. We just had to make a few adjustments to get the balance between the crowd, effects levels, and announcers just right, and that was it.”

What also excites him is the fact that radio has so many outlets for each team, which creates a kind of instant de facto network that can promulgate the idea of 5.1-surround sports radio, especially as DTS continues to add consumer capabilities. For instance, the Chiefs Radio Network comprises more than 50 stations, and more than 1,000 radio stations in the U.S. are now broadcasting in DTS Neural Surround.

The surround broadcasts of the Braves and Chiefs games, and discussions about a possible NBA team, are as far as the project has gone so far. Kline says it’s still in the proof-of-concept stage but adds that the reaction so far has been very positive. It’s just what radio needed: another dimension.