I wanted a speaker box for mounting a Samco 4Ω 15W, 2.75" speaker into my Taigen KV-1
I designed he original speaker enclosure first and then added an exaggerated opening for allowing air movement. The secondary component functions as the bass chamber with a small bass vent.
Size of the secondary compartment can be trimmed down to fit whatever hull sizes will allow (As in the KV-1 image attached for post-printing)
The prototype speaker box in my Taigen KV-1 (I do mount a sheet of 2mm polystyrene on the original electronics mounting plate)