Hmm... I use a RioVolt SP-250 (the Slim-X's little brother), but the firmware is very closely related for the two. For general MP3 encoding I use the same compile of
LAME, with the
All2Lame frontend as well, but after much testing I decided to stick with CBR encoding rather than VBR for this device; also, I'm using ID3v2 tags (which TAG doesn't write). My reasons have some thought behind them, although doubtless many here would tell me I'm doing it all wrong.
With tags at the beginning of each track the player doesn't have to seek to the end of a long file before telling me what's playing, and with ID3v2 any audio encoded as VBR
sometimes acts "wonky." So my current LAME encoding options are "--alt-preset cbr 192" with "--nogap" turned on via All2Lame, following which I use an ID3v2-capable tagger to write the tags by hand. Not the most elegant solution, but it works.
However, this still won't result in "gapless" audio on your Slim-X! Unfortunately, because of the way the iRiver firmware handles MP3 audio there will always be a small gap between MP3 tracks, similar to what occurs in Winamp if you aren't using a gapless-output plugin. For the life of me, I can't understand why they haven't taken a page from
CoolPlayer's book of tricks - integrated gapless output is the way to go. But so far, the only media an iRiver CD-based player will play in a
truly gapless fashion are Redbook (audio) CDs... and that was only added in the most recent firmware upgrades.
If you want gapless playback of compressed audio on an iRiver device, your best bet may be to encode your audio in an inherently gapless format (such as OGG or MPC - although iRiver has only promised support for OGG at this point) and pray that their firmware implementation allows for gapless playback. Sorry I couldn't offer any more help.
- M.
