Proper capacitors certainly help. Bass is a big dollop of energy being delivered all of a sudden - being why you can see the speaker moving. That energy has to

Proper capacitors certainly help. Bass is a big dollop of energy being delivered all of a sudden - being why you can see the speaker moving. That energy has to come from somewhere and it's just one of those things that if you shortcut it, you can tell. Similarly you can tell if speakers are in shitty boxes. The combination of the two leads to those "home theatre" things you see in shops that make a loud "splplplplpl" noise when something explodes on screen. Yuck. Other than that, I think it's mostly bollocks. I think a disappointingly large proportion of it can be summed up as "don't cut corners" which is why hifi gear from the 70's can still sound nice. If you replace the capacitors.