I think they would most likely sound wrong, in lack of better word, if they were misswired somehow. Maybe you wouldn't know how describe it, but the sound would be just wrong to the point of not wanting to listen to them. That's how you'll usually know you've got out of phase set.
To be a bit more precise, it's like a slight echo in the sound and artificial separation of channels.
To be a bit more precise, it's like a slight echo in the sound and artificial separation of channels.