I confess I don't fully get it when we say "perceived differences." I mean I know the meaning of perceived and I know what difference means, but you don't bi-wire just for the sake of difference, at least I didn', it must be a positive difference. I guess I tried it to gauge any difference, and then found out what it accomplished for me. That is, more defined bass with better extension, mids that I never knew were there before, and highs that are vivid, crisp, and complementary. Of course the soundstage was improved and a better overall accuracy was attained. I can't even imagine any scenario when bi-wiring would not make a positive difference, whether perceived or not. If you're not perceiving this positive difference, then you just don't have the ear. Same goes for the old speaker wire gauge argument. Of course copper is better than aluminum, and of couse thicker copper is better than thinner, and purer, thicker copper is better yet. Then there are silver and gold of course, but the point is the differences are real and positive in almost every situation and if not perceived, then the capability to perceive is simply absent.