Optimum audio size

Hi all, I am wondering how many kbps your audio (mp3) files are. Is there a recommended and/or optimum size?

I am trying to get the right balance between sound quality and not-too-big audio files which take up a lot of room on people’s devices and/or take too much time to download from the internet, especially in more isolated areas with poor internet connectivity.


I tried a number of CBR (constant bit rate) data rates, and found that 48 kbps mono gave fine quality for voice, with very little noticeable difference from 64 kbps.

Because we wanted to package one Gospel (Matthew) in the app, and we wanted the app download to be less than 25 MB, we reduced Matthew to 16 kbps. This is a compromise, and it’s not as “listenable” as 48 kbps.

One of the feature requests I’ve communicated for SAB is that, in an app like ours, the user could still download the 48 kbps.

Thanks! I’ll try 48 and see how it sounds. :slight_smile:

I’ve just started working with this. I was wondering if you have been using the 48 kbps mono. If so, how are you finding the audio quality at that setting?

Hi Roger,

Thanks for asking! We’ve settled on 64kbps. That seems to be the sweet spot for us.

Roger and @Roselle_Dobbs, our team has decided on a smaller size MP3 with a constant 24 kbps mono at 16,000 Hz. At this bit rate the whole New Testament with Genesis and introduction files is almost exactly 400 MB.

We of course can’t package all of that in the app on the Play Store, but at least that way the audio files don’t take up as much space on people’s phones. I’m not sure about your context, but here in West Africa I find that many people phones are almost completely at capacity and they have to go delete apps and/or media before they can even install any scripture app. I suspect that the default WhatsApp settings, in conjunction with their practice of exchanging video and audio files, are what make it so that people’s phones are so easily filled with media.