Apple’s new Mac Pro is quieter than iMac Pro, was kept in a ‘Stealth Enclosure’ to keep it a secret

https://macdailynews.com/wp-content/uploads/2019/06/190606_mac_pro_lattice.mp4
The lattice pattern on Mac Pro is based on a naturally occurring phenomenon in molecular crystal structures. A network of three-dimensional interlocking hemispheres, it increases the surface area, optimizing airflow and structural rigidity. To create the structure, a spherical array is machined onto the internal and external surfaces of the aluminum. The result is a lightweight lattice pattern that maximizes airflow while creating an extremely rigid structure.
Joe Rossignol for MacRumors:

On the latest episode of the Mac Power Users podcast, hosts David Sparks and Stephen Hackett had the opportunity to speak with Apple product manager Doug Brooks about the all-new Mac Pro, unveiled at WWDC 2019 earlier this week.
Brooks said that sound from the new Mac Pro under a desk measures around 10 decibels, making it quieter than an iMac Pro or the current Mac Pro on a desk, which he said are both already “virtually silent” at around 12 decibels.
Like many other Apple products, the new Mac Pro was kept in a “stealth enclosure” during testing in Apple’s labs to ensure that its design remained a secret until it was announced.

MacDailyNews Take: The “stealth enclosure” certainly worked!