BG BX-4850 THX Ultra 2 In-wall Sub

In-wall and in-ceiling speakers are becoming more and more popular as people aim to combine function and art in their homes. I have eyeballed in-wall subs and speakers as an alternative to having to hide my speakers and subs. Given the proper design, I am sure everyone will be happier with the outcome.

The BX-4850 THX sub, a design I had never seen before, measures 26 inches long and 4 inches wide. The in-wall sub has 4 modules each with 12 micro-woofers in them. According to the article, it has the same radiating area as two 18" subs. I would really like to do a side by side comparison of a standard sub and a in-wall design. Have you guys had much experience with this in-wall and in-ceiling designs.

From the article:

The BX-4850 THX Certified Ultra2 Subwoofer
consists of four modules, each containing 12 micro-precision woofers
mounted in their own enclosures and arranged in balanced pairs. The 48 woofers have a total radiating area equal to a two 18 inch drivers, yet fit completely inside a standard 2×4-inch stud-wall. All that is visible to the listener is a tall, slim grill 26 inches high and just 4 inches wide
(per module). The subwoofer modules are entirely self-contained, and do
not rely on the wall cavity in which they reside, or a separate
back-box, to deliver resonance-free, natural bass.