Is NIOS II needed?

I'd usually just try this out my self but i have no access to my DE2 board at the moment.

I've got an SDRAM controller in SOPC builder and also multiple memory mapped master components that are connected to the SDRAM controller. It all works fine. By having multiple mm master components i can have simultaneous buffers (for audio) all starting at different addresses (defined in a vhdl state machine).

Here's my query

For some reason i always thought i needed the NIOS II processor in there. Do i? The Avalon bus is an inherent feature of SOPC builder right? it has nothing to do with NIOS II.

Cheers