audioman58
I am always upgrading especially every few years as digital progresses , I mod my own Loudspeaker Xovers which the vast majority from the factory are average quality at best ,which can dramatically improve your Loudspeakers.
Modifying Xovers is definitely well worth the effort. Treatment inside enclosures is often minimalist and inadequate. Lots of room for improvement. I line all surfaces with a sound deadening material and fill the enclosure with a sound absorbing material (Mundorf Twaron Angel Hair Wadding).
Perhaps the best thing I did was ground every metal component even when it is earthed through a mains cable (cases, speaker frames or baskets. monitor stands, even tv stands or wall brackets) with a router. The recommended method is run a separate cable to the router for each connection rather than a create a daisy chain.