[quote author=Purvis11 link=1132375306/0#7 date=1132437393]Should I use and dampening material and what kind?
Im going to try and doubling the thickness of the baffle and the rest of the rattle seems to be coming from the last angle piece at the throat where there is the 2 inch opening. Should I double that thickness to?
THanks fot all your help and advice
Purvis [/quote]
Hello...yes indeed use some damping. I use the low itch white fiberglass. Most commonly you would use poly-stuff from an audio supplier. It has nice sonic quality and no itch , otherwise non toxic and some are fire-retardant. Fiberglass also has good properties for acoustic stuffing and makes a good damping material. It can be torn into different thicknesses and as long as you wear gloves and a dustmask it is ok to work with. I line all my sub boxes with a one inch matt of fiberglass and loose fill with torn apart chunks. You may have to play with the amount of damping until you find the right ratio. Too much can seriously muffle the sound and too little can give a bit of box noise. I have also used thin eggshell foamies for years for damping behind the cone or in ported boxes where otherwise pieces of loose poly or worse fiberglass can be blown out of the port. I also suggest damping for higher crossover frequencies with this box...it can sound a bit wild over 120 Hz or so but I found damping cures that up nice. I run at about 50-75Hz cutoff depending on the material I am listening to ,and have a loose stuff about 75 % of the volume of the sealed box. You can get up to 30 % more apparent volume to the driver with a full poly stuff . Check to the Vb of your driver...closer to 2 cubic feet and you may concider stuffing. WO sealed section is around .7 cubic feet, so a full stuff will make it around 1. Also note that some driver manufactures suggest damping for their drivers and others do not....I guess it depends on the woofer and x'sover point.
Also on the doubling of the baffle...yes double it up, double up the port, and any other join you double wont hurt.... screw and glue the hell out of it till it doesn't rattle.