[Hakka]

Yes, it is called duct board, the sheets size is 1200mm x 2400mm, cost $40 per sheet. It is available in 2 thicknesses (25mm, 50mm) and 2 densities. It has a foil backing on one side, the foil can be perforated or non perforated, I dont think it will matter which one you get.

I was advised to have the foil side facing out but after googling 'acoustic panels' I decided to go the other way.

I made 2 panels about 1m square, I just cut the duct board to size and wrapped it in material. I am planning to make 3 panels 1200mm x 2400mm, these will be mounted in wooden frames, I will place one on the front wall and one on each sidewall. This should cover all first reflection points for the front speakers.