All conversion will be done in software internally, so that you don't even need to have a sound card. Easy-Pro Midi to
audio converter is a software utility for converting
midi files(.mid,midi,rmi,kar) to chosen audio format (wav,mp3,ogg,wma).
Converting
midi file to Wav format enables you to easy burn them on an audio CD which can be played in any CD player.
After converting your
midi files to Mp3, Wma or
ogg format you can load them in mobile devices such as
portable mp3 players,
apple ipod, cell phones and similar gadgets.
Here are some key features of "Easy Pro Midi to
audio converter":
Fast conversion of
midi files without recording. All done automatically in shortest time possible (depending of computer speed conversion time is about 10% of
midi song length, for example 3 min song needs ~20 sec to be converted)
All conversion done in software internally, even sound card is not necessary
Convert multiple files at once-Batch conversion
Change key of songs-transpose
Adjust tempo of songs-set BPM
High quality internal sounds
Support for soundfont SF2 files for custom sound
Built-in
midi player
Quick convert mode where you just drop file or files from windows explorer and that's all!
Limitations:
14 days trial period; after the third day, the program will convert about 33% of song length
MP4 Converter
8.16 MB 
$ 29