Well ... my girlfriend doesn't hear it (she says maybe she hears what I am talking about ... not that that's saying much
) ... I'm one of those guys who buys a MacBook Pro and sits at the Apple Store for hours convincing them there is a pixel out or a defect in the screen.
I say the tone sounds great because it does ... it is only this crackle that concerns me. It is definitely there ... but I have never heard Alnico blues ... so maybe this is a characteristic I am just unfamiliar with but I do know these speakers are very fragile so it wouldn't surprise me if they have been slightly damaged in some way. The best way to describe it really is the firecracker fizzle.
I will try and post clips soon and see if you guys can hear what I am hearing. My rig is temporarily down right now.