Any thoughts for OLD school 800 series matrix products?
 

Current main speakers in my home system are now B&W 802 S3.

IF I ever want to go "multi-channel" I have at least a pair of 805 Matrix, and whatever the center equivalent was.

I see lots of people advertising crossover upgrades for the 802s... I've not mucked with them, but would ask if anyone has done any upgrades?

I sometimes look at bass alignment filters, when they come on the market, but my current system runs balanced from source to amplifier. Been tempted to use a B&W bass alignment filter, but they tend to sell for big $$ for what they are, and the few aftermarket offerings that offer balanced operation are WAY bigger $$$, and don't often show up on the market...