One of my clients asks during a room analysis session "what should I do with this panel?" It was then an absorber without any fabric covering it. This photo shows demonstrates our answer. It's a hybrid absorber/diffuser and we think it also looks great.
What is a hybrid panel?
This panel is an absorber/diffuser hybrid. First, we start with an absorber - in this case it is 100mm thick and so it provides decent absorption in the midrange. Left this way, a pure absorber can make a room sound more dead than we'd like, if many are used. It is typically high frequency absorption that creates a sense of "deadness." It's at this point we know we have gone too far.
Adding slats does two things. Firstly, it reduces some of the absorption, especially at high frequencies. We retain a greater degree of liveness in the room, but now we have selectively retained the midrange absorption. So it is a selective absorber. However, at the same time, we also have an amplitude diffuser. Each slot is conceived as a binary - 1 or 0. The number sequence serves to establish a pattern which results in diffusion at high frequencies.
The final result is that we achieve midrange absorption mixed with reduced high frequency absorption and diffusion. Ambience in the room is retained and improvements in clarity are made.
One of the great things about this type of panel is that they are fairly simple to build as a DIY project and one can add a large amount of diffusion and absorption to a room on a moderate budget.