PRO TIP
Alway upload to Reverbnation at 128kbps
They convert files to this rate if not, which damages the file, esp noticeable on acoustic music.
WHEREAS
While Soundcloud ALSO streams at 128, best sound from SoundCloud comes from uploading 16BIT wav files, as their algorithms convert everything to 128k MP3s, EVEN if you provide this format. Converting a file twice will often cause unwanted artefacts, so is always best avoided.
In short: Upload
128kbps to Reverbnation
16Bit WAV to Soundcloud
(This is subject to change if they ever update their sites, but was valid last time I checked)
JNxxx