Compressing .mp3 files further?

[tubeswell]

Is there a way of doing this short of keeping the recording clips really short? anyone know?

I can create my clips in garbage band on the Mac and then import them into iTunes as /mp3, but that only gets them so far

[Boots Deville]

What's the issues, taking up too much space?  The lower the bitrate you import them at, the smaller they will be, at the cost of fidelity.  Hard drive space is cheap, iPhone space, not so much... what are you trying to achieve?

[EL34]

As boots said
Lower bit rate = smaller file size = less quality

You can pick the .mp3 bit rate/compression rates when making a .mp3
I do it in Mixcraft by choosing the .mp3 settings from a drop down menu

Not sure how garage band works, but you should be able to export a song as a .mp3 and pick the settings
Maybe you are saying that, I was under the impression that you were letting I tunes create the .mp3???

[tubesornothing]

You can always choose a smaller sample size too.  Less quality though.

[tubeswell]

What's the issues, taking up too much space?  The lower the bitrate you import them at, the smaller they will be, at the cost of fidelity.  Hard drive space is cheap, iPhone space, not so much... what are you trying to achieve?

Just smaller file size to enable more convenient uploading - but it looks trickier the more I look into it. Might have to keep my clips shorts and punchy

[tubeswell]

Not sure how garage band works, but you should be able to export a song as a .mp3 and pick the settings
Maybe you are saying that, I was under the impression that you were letting I tunes create the .mp3???

Yep the tracks are made in GB and imported into iTunes with the import filter set to .mp3. Looking at it further, it appears there is some import setting adjustment capability. I'll have to muck around with it a bit and see.

[Bassmanster]

Another format:  Ogg Vorbis.

http://en.wikipedia.org/wiki/Vorbis#Quality:_Codec_comparisons

[PRR]

MP3 encoding is already about as good as it gets.

Other formats may do a wee bit better in size or quality, but not much.

ZIPping won't work at all. (MP3 already does the same result differently, leaving ZIP nothing to do but bloat some corners.)

You DO have options.

8-bit or 16-bit? 8-bit is pretty bad, you want 16.

Mono or stereo? On most tracks, stereo is larger but nowhere near twice the size: MP3 finds what is similar left and right and only sends it once.

Sample-rate? 11,025 to 44,100 samples per second.

Compression ratio? (This is not always called that, and in some encoders it may not be directly tweakable.)

Stereo 16-bit 44,100sps is CD quality. When MP3-compressed 4:1 it is very near-CD quality, but requires 320Kbps or 7-8 MegaBytes per 3 minutes. Compressed 11:1 it is 128K or 3 MegaBytes for 3 minutes.

Most MP3 encoding tools will show "128K" and "320K" options.

If you have a freebie website with 10MB storage, 320K allows 4 minutes of great fidelity, 128K allows 10 minutes of very good audio.

The majority of iTunes and Amazon MP3 offerings are encoded 128K. That's a happy-zone for many listeners.

I had an MP3 on a now-defunct website, encoded 8-bit mono 11,020sps and 88:1 compression. It streamed at only 1KB/second, was only a few seconds long, and even on dial-up would usually load before the graphics. Yeah, it took some spackle and sugar to make it not suck bad. Not a way to sell yourself.

[simonallaway]

On the Mac there's a program called XLD. It's very good at converting from various audio formats to MP3 or MP4. I use it for converting FLAC files (uncompressed CD backups) to files for my iPhone/iPod.

In GarageBand click on 'Share.....Export song to Disk'. Make sure you check 'Compress'  and choose MP3 for the drop down that says 'Compress Using'. Then tell it where you want to create the file...it doesn't have to be iTunes.

I'd agree with suggestions below about tweaking with bit-rate and content. 128kbps is a good compromise between clarity and size. Cymbals and strings can start to sound like someone's using a crappy flanger on the entire mix, but if someone is listening on less than decent audio gear, they won't care. You can try Variable Bit-rate too. Or mono...or 32kHz. Lots of options 

[Heinz]

I had the same problem just a week ago and found that lame has an option (-q 0) that affects the quality of "noise shaping and psychacoustic model". This feature controls what the encoder omits from the original data while minimizing the acoustic effect. Raising the quality slows down the encoding process, but that is not a problem for single files.

I found that I could compress CD rips with 96bps and -q 0 (highest quality) without an audible difference. It was really amazing when I checked it with headphones. Combine that with the other tweaks that were mentioned here and you can compress very small files with pretty good quality.