Dynamics varying with track position.

I’m finding that dynamics and timbre improve as the cartridge moves toward the inner 1/2 of the album. Running a DL 103r.  Aligned on my 303 arm with Regan paper protractor.  Also a slight emphasis on the left channel. Tried realigning/ checking overhang and I’ve heard no change.  Also checked the alignment with the Ortofon guide. Any one have a thought on the cause or remedy for this?
thanks. 
Lou