Why do people say low power amps should be good for bookshelf speakers?


I was in a BB Magnolia recently and they had a McIntosh MHA150 integrated headphone amp that can also do 50 watts per channel to speakers. The sales rep said it "should be good for small bookshelves but its not enough power for towers". 
I've never understood this line of reasoning.  Towers are typically more sensitive than bookshelves. Is there an actual reason a small amp like this couldn't do just fine for towers that are equally or more sensitive than similar bookshelves?
roberthz

Showing 1 response by ebanksms

A lot of good advice and logical reasoning above. I use Kef's relatively inefficient LS50s in my desktop and bedroom rigs. The desktop pair is driven by a low powered amp that is more than sufficient due to my proximity. 

I'm about 16 feet away from my bedroom LS50s in my usual listening position, and initially drove them with a 50 wpc Marantz receiver. The sound was fine for late night listening but fell apart if I cranked it up. I recently upgraded to a Purfi based amp and the LS50s really came alive.