Nobody is claiming that either.
But somebody is committing a straw man argument fallacy.
I think it’s generally agreed in the industry that a box is the worst possible shape for a loudspeaker cabinet.
The main reasons why most are built this way seems to be consumer expectations of domestic acceptability and manufacturing convenience.
The following extract is taken from diyaudioandvideo.com
What is the best shape for the box?
Internal reflections in the box combined with the vibration of the box itself can cause spikes in the frequency response of the system.
Different box shapes have different effects, with perfect cubes being the worst and spherical or egg shaped boxes being the best.
Although spheres have advantages, it is very difficult to create a spherical speaker box that is as strong as a typical rectangular box.
One good example of a spherical speaker is the Gallo Nucleus Solo above on the left which is made of rolled steel or brass.
An even better design is the sphere/tube concept by B&W shown on the right.
This design gets the benefits of a spherical design, but also adds a tapered tube at the back to eliminate all internal resonances.Shape Variation
Cube +-5.0 db
Rectangle +-3.0 db
Cylinder +-2.0 db
Beveled Cube +-1.5 db
Beveled Rectangle +-1.5 db
Sphere +-0.5 db
not really. it rings like a bell.
Yes it can, when used for TT platers, and is forged, but there is a reason for that too. Galvanization issues.
With Metal housed planars. Forged, won't GROW Barnacles (as fast) as cast will. Cast alu without a treatment, can get flakey in less than 5 years..
Double in thickness in 15 years. Aviation shot peen, stress relieves and removes, pocket resonance, issues, also..
Most speakers that use Aluminum, use it for it's milling ability.
EX: GR Research LS9 (Beta) and a few other.
Infinity Infinitesimal v.5 and 1.0 (cast)
CAST.. is actually the best , Highly porous, (to a point) dead silent.
Light, strong, easy to cast, easy to mill. A lot like a cast aluminum
engine block (neutralizing agent required)
Cast, Alu/Mag (no barnacil alloy) rims, dead silent. There is a reason they cast rims.. A lot quieter than a steel or spoke.
Schedule 40/6" is 7mm thick. Schedule 80 is 11mm thick. I am rusty on my structural eng.
Cylinders echo and gain? ... no, they behave pretty much like any other "tube" whether it is square or rectangular, but more consistent and easier to deal with.
All materials "ring". If you have a material that does not ring (at all), then it is probably not stiff (or only stiff in one dimension). You can always add dampening. Open the hood of your car and knock on the likely aluminum block. Tell me if it "rings".