I have a Kenwood KRC-391 Radio/Casette/CD Changer that is connected to the
OEM speakers in my Rover 25. I am going to fit KFC-1058S 100mm Dia and
KFC-6979ie 6"x9" connected to an Amp.

My question is, when you press the SRC button when the unit is switched on
Standby you get a list of speaker types to select from. Which is the best
setting for me to choose to get the best sound?

SP OFF
SP OEM
SP 6/6X9
SP 5/4

Cheers