Some of the explanations above while good, may still confuse you a bit so here is a bit of help with the basics of Sensitivity and watts. The following refers to continuous average power output:
Say you have a speaker rated at 89db sensitive 1Watt/1meter. That means that you will get 89db(of volume) with just 1 watt of power. For every 3db increase in Volume...you need a doubling of the watts to get that 3db.
So: 89db = 1Watt
92db = 2 Watts
95db = 4 Watts(doubles 2)
98db = 8 Watts
101db = 16Watts
104db = 32Watts
107db = 64 watts
110db = 128Watts
113db = 256 watts
Something you should be aware of is that it requires a 10db increase to get what is perceived as a doubling of the volume level. So, if you use the Wave 8 with an 89db sensitive speaker you are looking at a max of about 99db. Since your speakers are rated at 100Watts max then you can only get around 108db...no matter what amp you use(if the sensitivity is 89db).
95db is very loud...116 is near concert level...140db is a jet engine at 10 feet
You can see that if you have a speaker rated at 95db sensitive(like mine) then the scale above shifts so that 8Watts would produce 104-105db.
Now there are other variants...for instance the sensitivity rating is often innacurately measured. While the tweeter may be 95db the woofer may only be 87db...my bet is manufacturers split the difference. Bass often requires far more power which is why tubes sometimes make the bottom end a bit fuzzy...it's nice fuzz...but solid state amps will usually give more presence in the bass department. They also give more presence in the high frequencies which can sound shrill...which is why tube owners hate them, and why many Solid State owners eventually buy tubes.
I recently heard an 11 Watt integrated tube amp driving the B&W Nautilus 801s at a difficult 89db(B&W's impedence curve makes them harder than there spec sheet indicates). http://www.bwspeakers.com/products/g...1E0000E20E7DA6
at the end of the day Watts are not that important...If your speakers are rated at over 90db...you will get reasonably good volume levels...better yet...the Wave 8s will likely beat any solid state amp at twice or maybe even 3 times the price.
I have not heard them yet ... but other ASL amps are terrific and the design and build is quite solid. Check out reviews at UHF. Probably the toughest group of reviewers to impress. http://www.uhfmag.com/Issue58/Antique.html