The Dan Good Column
By Daniel Hyatt, Principal
DNAV Inc, Technology Solutions
2022 is off to a running start and I’ve already checked five states off in my travels to solve the problems of the broadcast industry. With more flexibility to travel and put my ears on problems in person, the common theme of improving broadcast audio is again front and center. Podcasts, broadcasts and tik tok style recording with an iPhone all present challenges with source audio, but when the entire air-chain sounds subpar, it’s time to take an adventure through the catacombs of wiring past to solve the riddle of the earworm.
Recently, I spent a week in the presence of a dynamic engineering team and highly regarded programming team to assist in uncovering the challenge of poor audio on an FM radio station in a major market. Much like an itch that’s just a few inches from the reach of a hand, the audio malefactor was slightly over the horizon of collective resolution.
The first stop on the audio voyage was source audio. A rapid interrogation of the programming team and production gurus showed a consistency in loading audio tracks for all stations in the cluster. All studio sources were consistent in their ingestion into the audio over IP system. Voice track studios were shared by staff of the station in question and other stations that sounded great. With no “ah-ha” moment, it was time to expand the expedition.
Working from the output of the AoIP system to the input of the STL was a curious unraveling of patches previously applied by the forefathers of the current engineering team. Sample rate inconsistencies, coupled with patches in and out of sample rate converters, AES splitters, gain structure distortion and various watermark enhancement devices were like a 1970’s gelatin, filled with salmon, hot dogs and vegetables – nothing was right.
Like a superhero with confounding strength and the curse of insomnia, I watched the moon rise and set two times as I forthrightly removed the malignancy of audio misdeeds. My assistant best described the feat as, “we drank a lot of coffee and pulled out a ton of wires and other stuff out.”
A Nucleus audio routing engine by SAS was installed prior to the STL and stream breakout. Within the Nucleus, a gated AGC processing chain was applied to protect output overshoot curing the gain inconsistencies. Sample rate conversion is automatic within the box and brought a consistency to audio looped through encoders. The Nucleus has a great encoding pre-processing element that proved to be more effective at lighting up the fancy green encoding bars than using outboard PPM enhancement devices. There was a gained element of separation and elimination of a metallic sound thought to be caused by a PPM device that was previously in-line. I highly recommend adding the Nucleus to your troubleshooting toolkit.
With smiles from programming and engineering, along with between one and four pats on the back, I was set to ride into the sunset, until the Program Director exclaimed “something still isn’t right!” With a quick tune of the radio dial, I could hear something in the mid and high frequencies that was now completely wrong!
Diving into the Gates Air IP200 STL software, I verified the equipment to be passing linear audio with no dropped packets. The wiring at the transmitter site was in good repair, yet the audio feeding into the audio processor was brittle. The question was no longer where the problem arose, but how.
How is the IP data stream transported to the transmitter site? If you guessed it traveled over a 3rd party wireless data provider, you win! With a phone call to the microwave data provider, a reflash of firmware and numerous wireless network switch considerations, the audio came back to life! The packets were being stripped in the transport layer!
This story is a tale of troubleshooting steps that could greatly improve your facility. How long has it been since a systems assessment has been done from microphone to antenna? Are you managing your own layer 3 transport or using a third-party provider? Is your facility using the latest in technology to perfect the audio stream? For stations using PPM encoding, are your methods the best and up-to-date or could you be driving listeners with fatiguing ringing sounds from older enhancement technologies?
Today is a great time to allocate time to be bigger, louder and cleaner in the new year for you and your listeners.
I always welcome your email and look forward to continuing to help the broadcast, audio, visual and production industry solve problems and create solutions to propel each to another milestone of great significance.
Happy New Year.