SVS SoundPath Subwoofer Isolation Feet

"there was zero thought or engineering to them"

The engineering is in the shape, the metal reinforcing shell, the size, the material, and the hardness. Their description, "optimized durometer elastomer feet" doesn’t describe the materials used, or the hardness. A durometer is simply an instrument used to measure the hardness of elastic materials, like tires for example. When they say, "optimized durometer elastomer" what they are saying is that these are manufactured to a specific hardness - or, durometer value. They do not share whether the material is rubber, sorbothane, silicone, or something else. However, customers who purchase the SVS feet really seem to like them - hard to argue with success. Here are similar products but less expensive, in silicone and in sorbothane.

At that price, maybe you get what you pay for?  Seriously,  how much engineering and materials can go into any product that sells for $10 per unit ?

Springs are better isolation.  Much better.

@mitch2 If they were so successful why change the hardness of the rubber so much?  So which product do they stand by?

You nailed it exactly. You can not isolate a subwoofer. Bass is extremely powerful. Play a 30 Hz test tone at 80 dB and walk around you house, go outside and walk around your house. The whole house will be rattling. Glasses on shelves, silverware in drawers, the walls, everything will be rattling, a symphony of rattles. And, there is absolutely nothing you can do to stop it. Fortunately, the loudest sound always wins and with the entire system playing the rattling is masked. Anything that is not masked is usually easy to find and stop. (like my movie screen)