Looking in from time to time. I now see people using or wanting to use Dyna-mat and lead shot. Both these materials will decouple the speaker from supportive material/enclosure which was originally intended to couple energy..though poorly understood and executed. The use of decoupling materials erodes the benefit of horn loading which is designed to maximise the use of acoustic energy. Materials suggested for use here actually store energy and increase the decay time.
I would suggest the use of steel shot or bronze shot in bearing form and not just random slag from some machine shop refusge or the use of any leaded materials. Both the steel shot or bronze material and shape will maintain reactivity and maintain the desired resonance control with out killing the live dynamics. Even with these more active materials there is a fine line of overfill before you mute the sound. air and dynamics. You can hear this happen in a progressive fashion. For internal wall surfaces of an enclosure there is a water based latex material that when painted on a flat surface will dry hard like concrete and have a rough granular finish. This finish as it drys is drawn into the pores of the wood or mdf, sealing and stiffening the material and helping to seal off the mdf/glue and all of it's ill affects and gross influences to the sound . Tom
I would suggest the use of steel shot or bronze shot in bearing form and not just random slag from some machine shop refusge or the use of any leaded materials. Both the steel shot or bronze material and shape will maintain reactivity and maintain the desired resonance control with out killing the live dynamics. Even with these more active materials there is a fine line of overfill before you mute the sound. air and dynamics. You can hear this happen in a progressive fashion. For internal wall surfaces of an enclosure there is a water based latex material that when painted on a flat surface will dry hard like concrete and have a rough granular finish. This finish as it drys is drawn into the pores of the wood or mdf, sealing and stiffening the material and helping to seal off the mdf/glue and all of it's ill affects and gross influences to the sound . Tom