The mysteries of audio quality (or why it’s so hard to sound great on social audio)
Have you ever wondered about the audio quality of social audio platforms? Or maybe you’re not sure why your podcast editor takes a sharp intake of breath when you say the next guest episode has been recorded on Zoom?
Let’s dive into some technical stuff to explore some technical aspects of audio quality and think about sample rates, and the impact they have on your listening experience.
The sample rate is the number of audio samples taken per second to capture and reproduce sound accurately. The higher the sample rate, the more data is being captured. So higher sample rates generally result in better audio quality and fidelity.
To put things into perspective…
A CD has a sample rate of 44.1 kHz
A Zoom call has a sample rate of around 32 kHz
Twitter Spaces audio could have a sample rate of 16 kHz or lower
So why is Spaces audio such low quality? Spaces uses Voice over Internet Protocol (VoIP) and the primary aim of this tech is to be understood in real time. The audio file needs to be small so it can move fast. If the audio is understandable as speech - job done. It needs no more data, no more finesse - it just needs to get the message from A to B.
Founder and CEO of Blast Radio Yousef Ali joined us on this week’s All Things Audio and got me thinking about this topic. Creators on Blast are broadcasting in 48 kHz, otherwise known as lossless quality. The audio is being beamed to the Blast cloud and back out to listeners on the app at a high sample rate and with little to no data being lost along the way. It’s the ultimate audiophile social audio platform. On this week’s show Yousef spoke a little about the difference between Spaces audio and Blast Radio audio, making a good point about trying to improve your audio using fancy tech.
He said: “…the technology we are using to talk in the Space is VoIP. So it's varying between 3khz to 15 khz depending on bandwidth fluctuations, etc. So it's not really great for audio quality.
“No matter how good your microphone is… it will only make so much of a difference because at the end of the day it's going to be downgraded to that sample rate. And that sample rate will determine the resolution of the audio.
As Twitter Spaces continues to evolve it’s possible improvements in audio quality may be introduced (though I doubt it is top of the roadmap). For those wanting a better quality recording of their Space, recording locally while broadcasting is an option. The All Things Audio podcast is recorded in this way using a Rodecaster Pro to enable the audio from my microphone to run into Spaces via the TRRS connection and directly into Adobe Audition at the same time.
Ultimately, even a high level understanding of the limitations of this type of audio can help meter expectations when it comes to creating social audio content.
✂️ Cut The Tape
VoIP provides a functional but by no means pristine means of communication.
An external microphone (USB or XLR) could improve how you sound in social audio spaces but ultimately all audio will be down sampled.
To capture a high quality version of your social audio arrange for hosts and co-hosts to record locally and collect their audio files afterwards using Google Drive, Dropbox or WeTransfer. (Need a hand piecing the conversation back together? Get in touch)
This blog was first written as a post for my weekly Substack Stop. Rewind. Play. It sparked a lot of interest so I figured I should reproduce it here on it website too - Suze
