Roen
Established Member
Which is better and why?
In the context of a ribbon drive,the implementation plays a much greater role than the relative properties of the underlying material, such that the question you ask is not all that meaningful. That said...
The increase rigidity of ceramic coated aluminium / magnesium alloy ought to permit a better response than straight aluminium, but since the ribbon will anyway be spanned, it's less of a factor than in a cone speaker.
So for example electrostatically charged mylar can readily outperform a ribbon speaker as its way lighter (that's an example of doing what your question does - ignoring the implementation and just concentrating on one aspect of the underlying component ) Of course, you're asking about ribbon, not ESL, drives, so you've already chosen the technology instead of auditioning what sounds best to you within your budget.
Which is better and why?