I imagine that both sound a little shitty!
Its a pretty open ended question really... how shit is "shit"?
I'd be inclined to go with a great speaker box and a less than great amplifier if I had to.
Simply because it is the transducer in the equation. It is what ultimately makes the sound...
No amp will fix a dysfunctional, boxy, rattly sounding speaker box.
That being said, not speaker box will save a dysfunctional, nasty sounding amplifier.
