An Acoustic System requires multiple interdependent components in order to achieve the lab tested acoustic results. Because there are so many variables, the acoustical product in question doesn’t even have to be sound absorbing as long as another component (fiberglass, backing, insulation, etc.) picks up the slack.
In stark contrast, a (true) Acoustic Panel is a stand alone. One and done. Performs the same in the lab as it does in the field. It requires no additional components, system setup, or complicated installation. SoundPly sound panels are true panels.
The large majority of acoustical products in the industry are systems for a reason: achieving a high NRC in the lab is much easier with a system than it is with a panel because a system allows for any number of additional components (such as fiberglass insulation and deep cavity space).
CAUTION: Acoustic Systems that require additional components often claim to be stand alone panels.