I'm not sure just how "stereo" the new pins are with their music/speech/effects sounds, but at best case it's just 2 channel stereo.
Most earlier machines are simply "dual-mono" fed into 2 speakers on the headbox to look like it's stereo....marketing trick.
For full surround effect you'd need 4 (well, 5) individual audio channels within the pinny to bring them out externally.
While modern pins have multiple audio tracks within them, they're digitally mixed converted as a mono/stereo output to the speakers, so there's no real way to get to the individual soundtracks.
I made an addon mp3 FX board for a pinny long ago, and since then was asked to make it into a surround system which was easy to do as all the sounds/synthesis were increased by adding more chips for the extra channels.
MM
thankyou for the great response. I will do some further investigating and will write Stern technical a question for any hints on how to achive my desire if they have a quick way or some detailed how to do instructions.
Even if it wasn't full stereo, having it loud in a room coming out of 5 or 6 speakers n being "surrounded" by the pinball machines audio coming to your ears from all directions (espescially behind you would be very cool n would instantly tickle the happy ear sensors of the brain if u know what I mean).
Because we are so used to the noise coming at us from in front only, speakers behind turned up loud might be very cool to the ears.....thanks for your information.