Bass is too trebley?

[ExD]

It's Fender Active P-Bass Special with stock electronics and hardware. No matter how I adjust the preamp, it always sounds trebley, this didn't happen with my P-Bass copy, which only had cheap pickups and a volume and tone knob. Could this be the noiseless pickups?

[anderbass]

You might really like flat wound strings on this bass.
I sure like-em on my (active) Fender Deluxe P-bass. (less clang... more bang !)

[ExD]

I do use flatwounds

The roundwounds that came with it were REALLY trebley, so I put some old flatwounds on it

[Jazz Ad]

Looks like you're looking for a passive bass.