testing Midi's in Slade?

Everytime I go to test them, it says I have to set it up. Do I need a program to do this?

No it is asking for a soundfont file

SLADE uses FluidSynth, so you need an SF2 soundfont. If you don't know where to find one, there are some pointers here. But you can't go wrong with Weeds.

While we're on the subject of audio in SLADE, I've been told it still doesn't recognize sounds larger than 65536 bytes. The length field in the DMX digital sound format is in fact 4 bytes long. This is especially significant in Strife's voices.wad file.

Not sure who told you that, but they might have been using an old version or something. I just tested voices.wad and SLADE detects and plays everything in it fine.

I prefer to use this soundfont. Really good quality, though relatively large.

Quasar said:

While we're on the subject of audio in SLADE, I've been told it still doesn't recognize sounds larger than 65536 bytes. The length field in the DMX digital sound format is in fact 4 bytes long. This is especially significant in Strife's voices.wad file.

I fixed that with r589 on Saturday 14th August 2010.