What is the minimum bit rate supported for MP3 files?

I’m just wondering if anyone can tell me what the minimum bit rate for MP3 files is, the manual I believe says 64kbps, but I’ve seen on this forum that people have mentioned 32kbps.  Will it go lower than 32kbps?  Also - what about variable bit rates, what exactly is supported (again, for MP3 files).   I have a Clip+ on the way from Amazon, and have been converting a bunch of MP3 audiobooks to lower bitrates to save a bit of space, but don’t want to make the files so low so that they can’t be played on my Clip+ at all!  Thanks in advance for any info!

jer989 wrote:

I’m just wondering if anyone can tell me what the minimum bit rate for MP3 files is, the manual I believe says 64kbps, but I’ve seen on this forum that people have mentioned 32kbps.  Will it go lower than 32kbps?  Also - what about variable bit rates, what exactly is supported (again, for MP3 files).   I have a Clip+ on the way from Amazon, and have been converting a bunch of MP3 audiobooks to lower bitrates to save a bit of space, but don’t want to make the files so low so that they can’t be played on my Clip+ at all!  Thanks in advance for any info!

I regularly listen to podcasts that are 32kbps mono. You’d have to ask JK98 how low you can go though. If anyone would know, it would be him, he listens to podcasts, audiobooks, lectures, the whole nine yards.

@jer989 wrote:

I’m just wondering if anyone can tell me what the minimum bit rate for MP3 files is, the manual I believe says 64kbps, but I’ve seen on this forum that people have mentioned 32kbps.  Will it go lower than 32kbps?  Also - what about variable bit rates, what exactly is supported (again, for MP3 files).   I have a Clip+ on the way from Amazon, and have been converting a bunch of MP3 audiobooks to lower bitrates to save a bit of space, but don’t want to make the files so low so that they can’t be played on my Clip+ at all!  Thanks in advance for any info!

All Mp3 players have to support all MPEG1 layer 3 bitrates, so thats 32k up to 320k.  VBR included.  Its been more then a decade since I saw a decoder that could not.

Bitrates lower then 32k are from the MPEG2 specification and are less widely used.  

I would probably use WMA for this.  Its a much better codec for very low bitrate files, and produces acceptable results for spoken word down to 8-16kbps in my experience.  I would not bother will the less common mp3 variants at that bitrate.  Even if they work they’ll sound quite poor.  

@saratoga wrote:


@jer989 wrote:

I’m just wondering if anyone can tell me what the minimum bit rate for MP3 files is, the manual I believe says 64kbps, but I’ve seen on this forum that people have mentioned 32kbps.  Will it go lower than 32kbps?  Also - what about variable bit rates, what exactly is supported (again, for MP3 files).   I have a Clip+ on the way from Amazon, and have been converting a bunch of MP3 audiobooks to lower bitrates to save a bit of space, but don’t want to make the files so low so that they can’t be played on my Clip+ at all!  Thanks in advance for any info!


 

All Mp3 players have to support all MPEG1 layer 3 bitrates, so thats 32k up to 320k.  VBR included.  Its been more then a decade since I saw a decoder that could not.

Bitrates lower then 32k are from the MPEG2 specification and are less widely used.  

I would probably use WMA for this.  Its a much better codec for very low bitrate files, and produces acceptable results for spoken word down to 8-16kbps in my experience.  I would not bother will the less common mp3 variants at that bitrate.  Even if they work they’ll sound quite poor.  

I use 16 kbps mp3 and 12 kbps wma lectures on my Clip+ and Fuze. They work fine. I have even tried 8 kbps mp3 on my Fuze, however the whistling artifacts were too great, and using this bitrate was unsatisfactory. I found 12 kbps wma or 16 kbps mp3 can sound quite satisfactory. WMA does sound better than mp3 at very low bitrates, with 12 kbps wma sounding about the same as 16 kbps mp3. I prefer not to use wma due to the shorter battery life. The wma files I have were downloaded that way. Using 24 kbps mp3 rather than 16 kbps does seem to be worth the small amount of extra space, and 32 kbps mono might also be worth the extra space. I don’t recommend using more than 32 kbps mono mp3 for spoken word files. The 16 and 24 kbps mp3 files were ones that were at that bitrate which I downloaded. When ripping spoken word files, I use 32 kbps mono mp3.

Thanks everyone for the info. - although it sounds like the Clip+ will handle low bitrates down to 16kbps (VBR or CBR) - I just thought it’d be a good idea to ask here and make sure everyone didn’t respond with a ‘hell no, that’ll never work!’ - and I’d have been converting these files for nothing!  Thanks again.