I pulled these out from storage a few days ago. They work well as subwoofers and also deliver on high frequencies. They need rehousing though; I do not like the shapes of the boxes and the black fabric coverings. Then there is the question of whether to port or seal the boxes. The speaker on the right is ported hence the difference in size and shape.
The functional difference between ported and sealed speakers is, the former type is louder and the latter delivers a higher fidelity. Seeing as I intend to use them in a gallery setting, sealed is the more appropriate option. This is fortunate because the calculations and design choices are simpler for the sealed speaker type. It is also smaller and the size tolerance is much greater. With a ported speaker, the measurements need to be much more precise because the airwave leaving the box needs to match the fundamental frequency of the monitor exactly if constructive interference is to amplify the membrane displacement and hence enhance volume.
The best material for cost and ease of construction is thick MDF which I can get cut accurately to size. For now, I am thinking of leaving the MDF bare and only sealing it for aesthetic and conceptual reasons. The speakers are what they are and to try to hide them would miss the point. They are sentinels of the sculpture, not just relayers of sound. Additionally, at the moment I feel that to paint them or cover them is to deny their real nature and contrast with the sculpture.
This web site gives all the information I need to construct the boxes and fit the subwoofers.
Use the Speaker Box Designer to determine the optimal volume for your enclosure.