I have taken a look at some designs at a dutch PA-speaker online store at www.speakerstore.nl under option constructions, and figured that the ideal volume of such a kabinet must be around 200 liter. But that is based on half a double 18" kab. and i want to use a 12" so there must be enough room to mix in the semi-horn idea.
Kabinet hight of 610mm and 470mm wide and 700mm deep must be oke.

Now maybe you would be happy to help designing a horn/reflex combined kabinet for this mag12 speaker with great output? I really think reflexkabinets don`t have enough output.

Thanks,

Erik