crimping vs soldering

Read the Audioquest white paper on cabling which goes in depth regarding this question. A solid cold crimp connection is next-best-thing to a molecular bond (electrowelding, which cannot be done at home) & for additional safeguard against oxidation a followup solder topcoat is advised, although unnecessary if you used a high pressure hydraulic crimper, again not typically found around the house.

I like to do a high voltage electronic weld followed by cryo treatment and my patented magical cable dance to make sure all bases are covered. You cannot go wrong with my method.

Follow Timo's advise an go to Cardas web page, there are lots of information in the FAQ. If you will solder, I recomend the WBT silver solder, it's melts at a low temp so
your cables insulation won't burn.

I don't have an educated opinion, however I read on Jon Risch's Web Site that soldering the spades on his DIY speaker cables can actually degrade the cable's performance.

Hmmmm...

To get a good solder conection ,you must have a good mechanical conection .so due both :)