[villieb]

I've been reading up on some the coding options and not sure what the above actually does...

Is it used for when people upgrade their speakers to the HiFi options or is it some sort of EQ for people with existing HiFi speakers?

Thanks

[Frobius]

In a nutshell, it flattens the EQ for an amplified system. The base stereo is tuned for the normal base speakers. Coding for HiFi is only really necessary if you're planning to swap out speakers and amp them - in that instance a flat EQ would be preferable to that tuned for speakers you don't have!