Letter [4723]from commented,

some mallets...like the innovative percussion anders astrand series...are made to be played on both marimba and vibraphone.

if you're playing on in the higher register of the marimba, it'd be fine to use vibe mallets. i'd personally just use a harder marimba mallet...but different people have different tastes.

i use vibe mallets on marimba often enough. they seem to work well when i'm playing (in the back-percussion section) with large orchestras. i also used vibe mallets when i needed a certain kind of edge to my sound for miyoshi's concerto for marimba and strings. i went through many mallets i had and they sounded the best. that is what counts. they had the best clarity and projection while retaining a good sound. greg