I solder then wipe all flux off.Is soldering speaker wires a good practice?
Are you extending them, or just at the ends? If you do this at the ends where they enter speaker terminals or on an amplifier, you would probably have more surface area in contact with bare wire because they can flex and increased surface area is what allows contact points to conduct current best. If you're extending the wires, a good crimp splice with solder & heat shrink is good, or a crimp splice with Heat N Seal shrink tube is water-tight. These are used on boats when the person wants the connection to work for a long time. When they don't care or when the connection is unlikely to fail under normal operation, a simple butt splice works very well.
I can hear the skin crawling on dyed in the wool audiophiles around the World.
