Composite means that it’s made from more than one wood.

In this example you are dealing with two separate materials. You have a composite board which has one half cedar (bottom half/end of the soundboard I think), and one half spruce (top half/end). It is covered (I believe), with a veneer so that it looks all the same from the outside. A laminated birch soundboard is a soundboard made entirely of very thin birch veneers that have been laminated together.

One can technically argue that both are laminate soundboards (because of the veneer over the cedar/spruce soundboard), but harpmakers generally exclude veneers from the classification of solid vs. laminate soundboard types.

To me, the type of soundboard doesn’t really matter. You can get a fantastic sounding harp with either type. My only preference for a ‘solid’ soundboard is because the tone tends to mature with age whereas a ‘laminate’ soundboard is more static.

I guess you could argue that. You could also argue that any soundboard with a veneer (regardless of whether or not the remainder was solid natural wood) that they are laminate soundboards. But generally veneers are exempt from this classification (in my experience).

Jerry Brown has a really good article (or two) about solid vs. laminate either on his website (harpkit.com) or in his book about harpmaking. I have his book and that’s where I read it, but I think he has it available online as well.