Are we talking about saturation remanence or
coercivity? The Hc of
computer and audio tapes are approximately the same, but the Mr is
quite a bit different.
I'd assumed it was the coercivity that was differnt, but mayne it's the
remanence. I will admit I've not done any measurement :-).
I am pretty sure that audio cassetes (even with a notch cut in them) do
not work well in ECMA34 tape drives. And that the data tapes make lousy
audio tapes at any normal bias setting.
-tony