@luizfcoimbria,
Sure, there have been advancements in some areas. IMO, the greatest gains have been in small, budget speaker performance. It's easy to make a large, heavy, cost-no-object speaker sound great. It doesn't have to push the boundaries of physics.
The best speakers I've heard to date don't use any esoteric materials or cabinets. In fact, they're simply updates of 30+ year old designs. For example, Stirling Broadcast's LS3/6. They use a plastic dome super tweeter with a published frequency roll-off point of 17kHz. Many audiophiles would see that number and immediately dismiss the speaker as inferior. They'd assume these speakers lack detail or "air" compared to those equipped with a diamond or beryllium tweeter. Yet, IME, these speakers have greater resolution and detail than the B&W Diamond series and other highly regarded brands.