Very wide question. What is the date and features of your new SR5 with respect to your 1998.
+1: every bass has its own sound. Ive got some verry similar rays that sound completely different. I even had 2 from the same year and same specs both with new strings and they where completely different.Every wood sounds unique.
Try to change the strings first.
Electronically they are the same - okay the magnets are 17 years older...
+1: every bass has its own sound. Ive got some verry similar rays that sound completely different. I even had 2 from the same year and same specs both with new strings and they where completely different.