Depends on SB. Most ISA SBs are configured via jumper, so they will be active even if the system does nothing.

I guess only PCI SBs and jumperless ISA SBs would be inactive, but I'm not really sure.

Well, if it is a PnP SoundBlaster, I'd guess not. If it does you might be able to solve it by creating multiple config files for the SB (one with the normal addresses and one with everything disabled/moved), copy the one you want on that specific startup item to the path CTCU reads and initialize the card.

It is an non pnp model, CT3900.
Thig is, I am using EMU8000 at 620h , SCB-55 at 330h , and an MIDI interface card at 330h as well. I could set it to 332h, now that i think about it it worked like that since the start.

I'd set it to 300h instead of 332h, if possible. It might be more compatible with games.

Possible address rages are: 330h, 332h, 334h, 336h.

But your SB supports MIDI at 300h, so you could put the SB at 300h and the other card at 330h.

Make sure no cards share the same address, so you have to change/disable addresses manually or let PNP handle it, but two things responding to same address is not good.

It won't blow up immediately even though there will be two cards driving the bus during read cycles, but it won't work properly either.

Edit: I don't know what kind of initializations your SB requires in config.sys or autoexec.bat but my cards do not need anything and games and my programs can just use the card without any initializations so the ports are active.