Construction cement (in a long cardboard tube) is also very good for cementing components to a circuit board or wooden base. Try Loctite PL375. Of course there is way too much of the glue for just the circuit board, but it can be also used for the joints of a wooden speaker box.
Another economical alternative for wire joints is a 6D wire nail. This will work if your base is fairly thick wood, I think 3/4" would be thick enough. Drive the nail into the base where you want to tie several connecting wires, wrap the component leads/ wires around the nail, and solder. Actually I never have done this with a cross-over network, but did do it at least a few times with some other circuits a good long time ago.
Strangely, in maybe the past ten years, I've found it difficult to find wire nails. However, it is very easy to find very substantial, thick, 6D nails. For many types of construction with wood, a wire nail holds things together well enough. In fact, the thicker nails that are now more prevalently sold tend to split wood. I wonder why that is? I think the answer is that nails are mostly sold by weight.
Regards,
Pete