I currently own Ibanez EDB basses (and a Cort Artisan C); I played on a Fender Jazz for years and also owned a couple of other brands/basses (Spector Legend, ESP B50, Cort Action, some more Ibanez: SR500, BTB205, GSR205, and so on). All of these were (more or less) ok for metal, so I'd say the only thing that matters is the way you want to sound, because almost any bass can be tweaked to blend pretty well in a metal band. The "metal sound" you were speaking about I think has more to do with the player's idea of a good tone, rather than a specific bass/brand sound and in most cases what you hear is not a clean raw tone anyway.