Apologies if this has already been posted...
The Sound System (J525) coding. Bit 7 00xxxx? allows setting according to the interior of the car. Mine was 00xxxx7 which is for Right-Hand-Drive/Leather/Gasoline. I changed it to 00xxxx5 which is for RHD/Cloth/Gasoline and the bass tone came booming out. It's now too much to have the bass on full. If you set 00xxxx1 which is for RHD/Cloth/Diesel then, for me the bass is too much.
At last, my sound system is perfect.
