Hi all, I have a question around acoustic foam.. I have some acoustic foam panels and some generic foam (mattress topper) the generic foam is denser than the acoustic foam and I you try and blow through it there is more restriction than the acoustic foam.
If you want to do the least, your mattress pad may do something but probably not much. I would suggest, like I always do, 4" thick rigid fiberglass or mineral wool panels spaced 4" off the wall. Also please read the Sticky Posts at the top of the forum for all the standard information and recommendations.
Why I ask these question and not go straight for the 704 foam is I can't get it here in New Zealand.... The heaviest insulation i can get is 27kg m3 which is a fair bit lighter than whats recommended so I need to look for other available options.
27kg/m3 isn't terrible. It's 1.5lb/ft3. Make your panels 4-8", 10-20cm, thick and you should be 99% there. Remember to use FRK on non-RFZ points for enhanced bass response. Also, experiment with gapping and angling panels about 1x the thickness.
Cool. Just make sure to gap them 1x the thickness and use FRK on non-RFZ zones to get the maximum bass absorption. You can lean them against the wall as well - I believe that helps distribute their effective range while compensating somewhat for the 'midrange hole' that gapping creates.