Correct way to attach speaker wires... Wait, what!!!

Better to solder the connection to the spade or bananas you get a much higher contact area and it will stay secure longer then a simple crimp. Also more corrosion resistant. tin'd bare wire is also good or even bare wire. In the industrial military electronics world you would never use a simple crimped on connector unless you wanted it to fail or lose conductivity. Just my 2 cents 

Thanks guys. Hey Erik what is WBT?

Heat from solder can be bad for high-end wire that's why many higher-end manufacturers Just a use a quality crimp on connector I use Analysis Plus cables and they are by no means the cheapest they use a very soft brass pressed on terminations

Hi Autre, WBT is a famous German connector manufacturer.

http://partsconnexion.com/connectors_brand_wbt.html

All connectors degrade sound. All, regardless of cost. Bare wire is best. Do the comparisons and it is obvious. So, go with bare wire.

1) just clean every so often and no oxidatiobpn issues.
2) or just thin the stripped area - good option

You can buy some very good sounding tinned speaker wire from Duelund. Their 16 gauge stranded in cotton wire.  Makes great speaker cable and costs $10 meter.  It is tinned already.  You can buy it from Parts Connextion if interested.