As a neutral Hal I'd imagine that would be the right choice for an entity like Hal 9000. This is, of course that you provide it with no gender specific traits to which it would attach itself.
You could always use a male voice and tweak the settings (pitch, speed, etc.)
Settings could always be changed by loading a different brain with an assigned gender if that is an issue. Otherwise, experiment, save your settings, backup your brain files before you do any serious modification.
Good luck!