How many watts do I need?

How much power should your amplifier have to properly drive your speakers? (subtitled in English and Dutch - Nederlands ondertiteld).
Excell sheet: copy the link below into your browser (it will not work as direct link).
www.patreon.co...
This video on Patreon: / thehbchannel
The written English version:TBA
Dutch written version: NNB
Link to my book: thehbproject.co....
My personal site: www.hansbeekhuy...
My site: www.theHBprojec...
KZbin channel: / thehansbeekhuyzenchannel
Facebook: / hansbeekhuyzen
Google+: www.google.com/...
Twitter: / hansbeekhuyzen
Kindle store: tinyurl.com/h6e...
Apple iBook Store: tinyurl.com/jxv...