Sound absorption is first step to improve sound, but Thickness matters. Any room will have problem below 1000 Hz and not in the high frequency. 1 inch panel absorption will starts from 1000 hz and above and 2" panel starts absorption from 500hz and above. We recommend minimum 3" panels for board band absorption which will start absorption from 250Hz and above. We have Curve 75 which is 75mm thickness and the size is 2 by 2 ft. Its Velvet Coated Unique Foam and the size, color, design can be customized as per your choice. It can be placed in front wall to absorb the reflection coming from the rear wall, In rear wall, you can place in center to absorb the center channel and of course in celling between front row and the screen. Always make sure you place the curve 75 above 2f from the floor and you should cover up to ear height.  if your RT60 is high than you can place more panels in front wall to control RT60. Dont get confused by NRC values, NRC will vary depending on Frequency. For 1" panel, the NRC at 1000HZ could be .95 or 0.99 but for 500Hz it may be for .3 or .4 and 250Hz it could be 0. So please take a note while designing your hifi systems.