I know it is determined by the fourth hex code in this code (at least for the common Nintendo SPC system)
F7 XX XX XXI know this much, but then we get to the FIR values themselves. Now, what I am trying to do is get the same FIR filter variables that the SNES version of At Doom's Gate (from the SNES version of Doom, of course) uses, which is this
FA 0A 1A 13 13 1A 0A FANow, the game I am basing these codes off of is EarthBound, and I know Doom uses a modified version of the normal Nintendo SPC700 sound system, but to what extent I am not really sure, and so does EarthBound, which simply adds in three debug codes. But with that knowledge I know for sure that the two games share the same exact echo settings. And I want to know, how in the hell do you determine what the FIR filter variables are going to be with only the one single hex code that sets them???