Keppy's MIDI Converter is a freeware, fully functional MIDI to WAV converter.
The installer will download and install .Net 4.5 if you're missing it and can run in both 32-bit and 64-bit. While Keppy's MIDI Converter calls itself a MIDI to WAV converter, it actually can also convert your MIDI to WAV, OG3, and MP3.
You can go to "Action," "Import." or darg-and-drop your MIDI files directly into the application. Information on each MIDI is provided including Notes, Length, Size, and more. Settings allow you to make many changes, if you desire, before converting to WAV. Some of these settings are Volume, Voice Limiter, and more. Advanced settings available include Audio Frequency, disable audio effects, force constant bitrate, and more.... More Info »