Silver vs. Cooper speakers cables

I want to know if silver cables are really better than cooper.
Up to the moment I use Audioquest Volcano biwire cooper cables but many people recomend move to silver for my Tannoy Speakers.
Pure silver or hibrid cooper silver ?
AQ silver cables are very expensive, but I can saw that there are many silver cables at very affordable price like Silver Audio or Analysis Plus.
Please let your opinions and recomendations.
Thanks.