I have a Jasper Marine, 3/16 bottom with a welded centre keel and full egg crate/boxed hull - no spray foam.  It also rides loud - in decent chop every wave can sound like the beat of a drum.  I think the noise is just what you get when there is no spray foam - I'm sure 1/4" bottom plate would help with the noise.  I don't see any way of addressing it other than spray (which has its own issues)