I will explore Bacch soundstage enhancement and crosstalk cancellation. They have put forth a trial version for download. I went through the steps but coinccidently caught a virus. Not sure if related to that particular site. But it never occurs to me Bacch will help on timbre tuning.
IME (to my ears) the Bacch applies some very gentle PEQ (it has several target curves to select from), time and phase alignment, and crosstalk (etc.) processing.
Try the Fosi gr70 all tube headphone amp as a preamp. its $200 . Its surprisingly the best thing Fosi ever made. Its tuned very warm but no loss in detail or top end, just the lower register extends deep and wide, full. . I couldn't care less about Fosi and Aiyima , but the gr70 is something worth checking out....surprisingly fantastic as a preamp. Not even kidding. its that good.