mp3 File Size Reduction question

Hey guys,

So I’m testing the waters submitting some of my songs to music supervisors. Some only accept mp3’s with a very small 320 KB size limit. When I export to an mp3 file within the ‘Export Audio Mixdown’ window, I’ve always used the standard default settings of 160 bit rate, 44.100 KHz. So an average song results in 5-20 MB depending on the length and amount of tracks, especially after mastering, which is fine for soundcloud type sites. I know there are lots of free mp3 compression apps out there, some of which get good reviews, but I’d feel much more comfortable to do this within Cubase, if this is the wise choice. Can you recommend the easiest method in Cubase, which will reduce my songs to very small like 320 KB size range, but WITHOUT losing any of my original sound recording quality. I’m assuming I can do this directly during the ‘Export Audio Mixdown’ window step.



Are you sure they don’t mean 320 kbps bitrate? I don’t think a four minute song could ever fit in a 320 kb sized mp3 file, no matter how low you go with the mp3 bitrate, or with additional compression tools.

Thanks so much for your response! I will contact the site, it’s likely a typo on their FAQ. Just the same, do you recommend any specific bit rate for an average 4 minute song?

If you’re comfortable with 160k, you could stay with that, but iTunes uses 256k minimum VBR for their AAC, and Amazon uses 320k CBR (or equivalent VBR) for their MP3. You could try the higher settings and see what you think. The file sizes will be somewhat larger.

MP3 File Size Calculations (CBR)

Kbps = bits per second / 8 = Bytes per second x 60 seconds = Bytes per minute x 60 minutes = Bytes per hour

160 Kbps per minute = 1.2 MB
320 Kbps per minute = 2.4 MB

I always prefer to use 320 (CBR) because in most cases it won’t really matter if a 4 minute song uses 4.8 MB (160) or 9.6 MB (320)? Both are still next to nothing compared to WAV or FLAC files. 320 just sounds a lot better especially in the high frequency region. And if size really matters you can always consider to drop down to 256 or 192, or use VBR, which will also reduce the file size a little.