This is one in a series about optimizing your airchain. The author is director of content for Telos Alliance.
There is a widespread sentiment within the broadcast community that radio, as an industry and as a medium, is becoming increasingly irrelevant to today’s audience. “Radio” in the traditional sense — an RF signal emanating from a transmitter and received by a tuner — has more competition than ever, and there is no denying that listening habits have shifted markedly in recent years.
But radio isn’t dying: It is changing and evolving, much like it has for the past 100 years.
AM gave way to FM, which is now being challenged by streaming audio. Rack-mounted solid-state transmitters now deliver the same power as much larger tube rigs of the past, and with much greater efficiency and reliability.
Optimizing your airchain to meet the needs of what radio is today reveals a mix of practices that are as relevant now as they were many years ago, and some that are uniquely reflective of the current media landscape.
One example of something that has not changed is the importance of high-quality source audio.
It mattered in the days of vinyl and tape, and it matters just as much now — arguably more so — in the era of digital audio files.
Music libraries consisting of low-bitrate MP2s and MP3s to save once-precious hard drive space still exist, but have no place in a radio station today. This content’s audio quality is already compromised before being pre-emphasized and clipped in the analog FM signal, or subjected to multiple rounds of lossy transcoding in HD, DAB and streaming paths.
Speaking of source audio, the importance of normalizing levels when importing songs and commercials cannot be overstated.
This can easily be accomplished using automated workflows supported by playout systems, either by making a static gain change or changing metadata values.
Normalization not only ensures consistent loudness across the entire library, but it makes things easier on operators and talent running the board. It also means that downstream processing can be relaxed as levels are already well-controlled at the input.
That’s a win for the audience, who get better-sounding audio and are more likely to stick around for the next song.
Something that has changed significantly in recent years is the in-car listening experience.
Radios no longer look like radios; they’re integrated into touch-sensitive vehicle-wide infotainment systems. With technologies like DTS AutoStage, manufacturers are able to deliver a more consistent experience across platforms.
That’s a boon for the driver and passengers, but it also means expectations are higher for traditional radio. Streaming services such as Spotify and Apple Music deliver excellent-sounding audio, and listeners are expecting the same from their local stations.
There is also some behind-the-scenes magic going on that should be considered when making decisions about audio processing, loudness and modulation.
In an effort to avoid annoying listeners with source-to-source loudness shifts, many systems endeavor to match the loudness of a newly selected source to that of the one prior. This can negate attempts to build perceived loudness with aggressive processing; if the radio is going to attenuate loudness, there is little reason to compromise quality by crushing the audio.
Consider this a gift, as it lets you set your processing to be consistent and punchy while retaining the impression of dynamics. Loudness-wise, aim to be in the middle of the field among your in-market competition.
On the RF side, traditional receivers have largely been replaced by software-defined receivers. While both perform a similar decoding function, they do so in ways that impact decisions about modulation and audio processing in unexpected ways. SDRs do not tolerate over-modulation well and will cause audible distortion on modulation in excess of 110%.
Finally, AM and FM listenership may be on the decline, but the streaming audience is growing, so it is imperative to treat your station’s streaming audio with the same level of care and attention as your terrestrial signal.
This is especially important when it comes to processing. Blowing the dust off a shelved wideband AGC isn’t going to cut it, and feeding the output of your FM processor to your streaming encoder is a big no-no.
At the very least, you can use the HD output of your on-air processor for your stream, but ideally, it would have its own purpose-built processor optimized for coded audio and low bit rates. Many Omnia processors include independent streaming processing and encoding for each audio path, or were designed from the ground up specifically for streaming.
There is no magic bullet for optimizing your airchain. The “secret sauce,” if there is one, is made up of an unwavering commitment to quality, the application of some common-sense audio basics, an understanding of how emerging technology affects your approach to audio and recognizing that radio faces some stiff competition from other players on the digital dashboard.
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