Help With Converting Midi to Audio

I've recorded audio for quite some time and even done a few songs here and there with midi in the past. However, I've written a piece of music that is all midi. I used several soft synths in the creation of the song and can hear the sound just fine. However, when I performed my normal mixdown procedure and exported the audio, I ended up with a monster-sized file that is unmanageable. I want to convert the midi to audio. Reading through both the manual and several threads here in the user's forum, I see I need to have a soft synth inserted. Since I recorded the track using a soft synth I assume I have one inserted. Is this correct? I've tried using the "Bounce to Tracks" dialogue but when I do the bounce I end up with a new track with no audio rendered on it. In the "Bounce to Tracks" dialogue box, I've set my "Destination" as "New Track (17"). (17 being the number of the new track created). I'm using no preset. For the "Source Category", I'm choosing "Tracks" and also choosing the track number corresponding to the midi track I want to bounce from the "Source Buses/Tracks" box. (In this case Track 2 and it shows I'm using Cakewalk Sound Center as the source). "Dithering" is set to "Triangular". All the "Mix Enables" are set except for "Audible Bounce" and "Live Input". I then hit okay and I can see the progress of the bounce. A new track is created on track 17 but rather than being populated with waveforms I see only a long, uninterrupted line that extends the length of the song. If I mute the original MIDI track, I hear no sound. What am I doing wrong? Any help would be greatly appreciated. David

However, when I performed my normal mixdown procedure and exported the audio, I ended up with a monster-sized file that is unmanageable.

What is unmanageable? 

A 44.1KHz WAV file is typically 10MB per minute of recording. So if it's a 5 minute piece, the WAV file should be about 50MB. It doesn't make any difference whether you have 1 track or 200 tracks. Perhaps you have some MIDI data far out in the track which is making Sonar think the piece is longer and it's exporting a lot of silence or you are exporting to a format other than a 44.1KHz WAV file.


Also, if you are using all MIDI and softsynth tracks, there is no need to Bounce to Tracks. When you export, Sonar will take care of that for you. 

Unmanageable in this case is a little over a gigabyte for a 3:48 second piece. Typically I'm in the range you guys are talking about - about 50mb or so for a piece that size. So that answers one question I had. The file shouldn't be anywhere near that size. I wasn't sure since I'd never recorded a song composed entirely of MIDI data before. I'll go over it with a fine-tooth comb and update later today. Thanks for your help everyone. I certainly appreciate it!