Condicionamento acústico extremamente eficaz, vendo porque estou a remodelar o espaço Hi-Fi e na nova configuração eles não são necessários, o efeito é excessivo. Antes usava para cancelar eco / excesso na resposta de frequências médias / agudas.

Abaixo deixo descrição do site do fabricante. Vendo por 80 euros o par, preço novo: cada um 109 euros + portes. Estão como novos.
Posso entregar em Algés ou Lisboa.

Bluetone Acoustics Binary AbFuser Acoustic Panels - Sound Insulation Acoustic Panels - Acoustic Absorber and Diffuser for Home Cinema, Studio, Living Room - Acoustic Panel (100 x 50 x 5 cm, Blue)

Acoustic diffuser and sound absorber in one panel: Binary AbFuser is a hybrid acoustic panel designed for the acoustic treatment of all types of rooms such as recording studios, home cinemas, music clubs, offices and living rooms. It provides Class A sound absorption and additional diffusion of medium and high frequencies.

Top quality: the product is made of high-quality materials. The cushioning material is acoustic wool with a density of 80 kg/m3 (non-flammable, class A). The frame is made of non-flammable furniture board and is covered with an acoustic fabric. The front diffusion plate is made of lacquered HDF board.

Enjoy the audio experience: unique combination of sound absorption and diffusion. The broadband sound absorber and binary diffuser ensure a perfectly balanced sound image, while still making the room sound "alive."

Handmade in the European Union. The product is handmade in Poland from certified materials. It is environmentally friendly and harmless to health. Wall brackets for easy mounting are included.