Audio Streaming for Radio: Bitrate, AAC+, Latency, and Sound Quality

Sound quality is one of the factors that most influences whether a listener stays or leaves your radio station. But terms like bitrate, codec, AAC+, and latency often confuse beginners. In this article, we explain each concept simply so you can configure your radio's streaming with the best possible quality.

What is audio streaming?

Streaming is the continuous transmission of audio over the internet. Instead of downloading an entire file, the listener receives sound in real-time, in small chunks, while listening. A streaming server (like Icecast or SHOUTcast, used behind the platforms) receives the audio from your radio and distributes it simultaneously to all connected listeners.

Bitrate: what is it and why does it matter?

The bitrate is the amount of data used per second of audio, measured in kbps (kilobits per second). The higher the bitrate, the more information - and generally, better quality. But there’s a balance: very high bitrates consume more data from the listener and more bandwidth from the radio.

• 32-64 kbps: suitable for voice (podcasts, talk radios) or limited connections.
• 96-128 kbps: the ideal range for music in most radios.
• 192-320 kbps: high fidelity, for demanding audiences, with higher consumption.

Codecs: MP3 vs AAC+

The codec is the method used to compress audio. The two most common in radio are:

• MP3: the most traditional and compatible, but less efficient. Requires higher bitrates to sound good.
• AAC+ (HE-AAC): more modern and efficient. Delivers the same quality as MP3 at about half the bitrate. An AAC+ stream at 64 kbps sounds comparable to an MP3 at 128 kbps.

In practice, AAC+ is the winner for online radio: better quality, lower data consumption, and a more stable experience for those listening on mobile.

The reference table

Latency: the delay in streaming

Latency is the time between the audio leaving the studio and reaching the listener. In radio streaming, a few seconds of delay are normal and not problematic, as the transmission is one-way - the listener does not need to interact in real-time. Latency is only critical in applications like live calls with audience participation, where specific adjustments are made.

Stability: just as important as quality

There’s no point in having a high bitrate if the transmission drops or freezes. Stability depends on the server infrastructure and its proximity to the listeners. Servers in Brazil, for example, deliver lower latency and more stability for the Brazilian audience. Therefore, choosing a platform with robust and localized infrastructure is crucial for the final experience.

Adaptive audio and multiple streams

Modern platforms can offer different stream qualities for different situations. Thus, those on a fast connection receive high quality, while those on a limited mobile network receive a lighter stream, without freezing. This ensures that everyone can listen well, regardless of their connection.

Tips for the best sound

• Prefer AAC+ at 128 kbps for music - the best balance between quality and consumption.
• Normalize the volume of tracks to avoid abrupt differences between songs.
• Use a platform with servers close to your audience.
• Avoid recompressing already compressed files: always start with the audio in the best possible quality.

Conclusion

Understanding bitrate, codecs, latency, and stability helps you provide sound that meets the standards of your programming. For most radios, AAC+ at 128 kbps is the ideal setting - FM quality with moderate consumption. Adding this to a stable and localized infrastructure, like the one BRASCAST offers in Brazil, your radio delivers a professional audio experience that makes listeners want to stay.