The easiest way to remove wax very quickly is to use trichloroethylene, which will dissolve wax like no tomorrow. pre-heat the wood, and as you wipe them heat the wood with a heat gun.

The tri will cut the wax, and after several applications can draw (wick) the wax over into the cloth. Unlike naptha, this is not very flammable.

It will dissolve and remove wax like there is no tomorrow.test on your wood to make sure there aren't any weird interactions, but I wouldn't expect it. Finish by sanding as others have detailed. I personally finish with Watco Med Walnut doe great looking speakers. Final coat is with Johnson paste wax (1 coat)

If you're into waxed speakers you can heat (heatgun) the wood and fill the grain with wax, and use 500 or 600 grit sandpaper to fully fill the grain, then polish to have highly polished speakers which are silky smooth.

Personally I like the use of med walnut Watco by itself, with occasional re-application to maintain the speaker look.

Larry