Very confusing question. Let's start with this bit...
I have my YAMAHA DX7 plugged in with MIDI cables in and out to the soundblaster. If I play on the keyboard, it makes noise as expected. I guess it sends midi because the audio output is not hooked up.
If the DX-7's audio outs are not hooked to anything, then clearly you must be triggering one of the MIDI synths available on the SoundBlaster.
The problem is in getting multiple channels to play (with different sounds). The only thing I can get to work as far as playing a MIDI file is sending everything through channel 1.
That should not be a problem at all with the SB Live. For each MIDI track in your software, have you selected a separate channel and is the destination device the A or B SB Live! MIDI Synth?
With the DX-7, that might not be multitimbral -- you might only be able to get one sound at a time out of it. But you said it's audio outs are not connected to anything, so that can't be your issue.
Also, the DX7 needs to be turned on for any MIDI sound to happen at all.
Well, duh... how do you expect it to send any MIDI messages if it's off?
Also, when I pick sounds through different channels, I don't get the standard MIDI sounds. If I pick sound #7, I get the DX7's sound #7, etc....
Ok, here's where we really enter the Twilight Zone... you already said you only get sounds when you use Channel 1, now we have different channels? Perhaps you mean different patches or program numbers.
What "standard MIDI sounds" do you mean? I'm guessing the so-called General MIDI set, where program 0 (or 1, depending on the synth) = acoustic piano, program 35 (or 36) = fretless bass, etc. The DX-7 was made before the GM spec, it is not a GM-compliant synth, so its program numbers correspond to a different set of sounds. But wait. Your DX-7's audio outputs are not connected, you said... then you certainly cannot be getting the DX-7's sound from any patch.
So at this point all I can do is throw up my hands and say: we need more info, accurate info. The DX-7's audio output cannot be both hooked up and not hooked up.
I sent things out through "SB Live! MIDI Out (10C0)"
That's the output port of the MIDI interface on the SB Live. That means you are trying to trigger an external device (the DX-7, I presume). But again we run smack into contradictory statements that you made.
Before bailing, let me point out a thing or two that might help you clarify what you are trying to do and why it might not be working for you.
As MIDI output devices (possible destinations for the MIDI data to be sent from your sequencer), you have this MIDI Out on the SB Live, plus the others you listed. Here's a description of what the others are.
Creative S/W Synth - this is a software synth that comes with the SB Live. It is not very useful because it responds to slowly to be used in realtime, and sounds pretty bad too. Its output would be heard through the SB Live's audio output if it's not disabled in the mixer utility for the soundcard.
A: SB Live! Midi Synth and B: SB Live! Midi Synth - the SB Live has two hardware-based synths, labeled A and B. These address sound sets in the computer's memory, which is how you can get different sound sets (called Sound Fonts) out of the SB Live's onboard synth. When you load a Sound Font instead of the default sound set, it shows up as Sound Font device or something like that instead if synths A and B. Their output would likewise be heard through the SB Live's audio output, if they're not disabled in the mixer utility for the soundcard.
Nemesys MidiOut: Port 1 -- I don't know what this is for sure, but Nemesys was the developer of Gigasampler, which is a software sample player... do you have one of their products too? But why would it be called MidiOut? Puzzling.
MIDI Mapper - this is a Microsoft utility on the computer that lets you define a MIDI mapping. It would be used to remap MIDI channels between the source and destination. Say you had a GM MIDI file, and wanted to play it using similar sounds on a non-GM synth. You could change all the patch numbers in your file's tracks. but then you have to do that again to get it back the way it was before. With a MIDI mapping, you could reassign where Channel 1's data from the sequencer actually gets sent. Then you can always use this map instead of changing sequencer channel assignments back and forth. Much more sensible, especially if you are going to use this combination of hardware and software a lot. But most people don't use this much, and you would have to understand it and have set it up to get anything out of it, so I'd ignore it for now.
