What amps are you using? Try using an eq, or try a few different value volume pots. I put a Schaller 5 way switch in mine, and re-routed the pickups, using the diagrams that came with the switch. You can get the switch through Stewmac. One other thing: My Brent Mason is from 2016 with a maple board and has a Brent Mason bridge pickup in the bridge, and a 408 in the neck..the first one I had was a 2013, with 2- 408 pickups, and a rosewood board, and was very low-mid, and bass focused, so I moved it on.
I think the maple fretboard makes a big difference in the overall tone. It was the reason I bought it, after trying it through my amp/pedalboard set-up. Good luck, I hope you get it worked out, they are great guitars.