[LBaudio]

Only flece will not give you sufficient strenght. Apply a couple layers of fiberglass and smooth/design them with filler with strands. You can apply damping plates on inside panel walls to supress resonances and ringing of the enclosure, which is common issue with any fiberglass enclosure/pod

dont save material where it is not needed to... make panel walls thick and super solid...it is always a good thing

 

[LBaudio]

There is a material like fleece that is many times used for small panels like mids and tweeters, some use it even for midbass door panels. After soaking one layer of material is of about 4-5mm thickness and pretty strong. Installers apply only filler with strands over this fleece material to smooth everything out and wrap it in material of choice. Me personaly, Im not a fan of it.

Imho, spherical enclosures help with lowering diffraction on outside surface edges, and eliminates/diminishing standing waves inside of the enclosure.