Solid to Shell Conversion

Hallo Everyone

I have a model of a loudspeaker enclosure in solid. Due to the time taken in the simulation in 3D, Acoustics solid interaction module, i am thinking of using the Acoustics shell interaction module as used in the vented loudspeaker enclosure model from comsol tutorials.

I am using comsol 5.1 and i am trying to use the geometry-convert-midsurface to convert my solid to shell model. Is it the right approach? Or do i need to do some more processing in between to convert my solid model to shell model,