Hi folks. Building a house and the home cinema is in the basement - it's a great space, 10x6 meters, but with polished concrete floors and plaster over hollowcore ceiling the sound is very echoey. Is there a cheap / DIY solution that really works? I read about putting insulation board in a picture frame and hanging a few on the walls, along with plenty of soft furnishings. Or would I be better covering the ceiling in egg cartons, or convincing the missus to cover the floor with a giant rug?? I would appreciate hearing your experience in this area.