I have got a 3" sound reducing valve that will be up for sale with it soon. It's on eBay and someone has clicked by it now but refuses to pay!? He has a couple of days to pay before I list it on here
I've got one of those too, but I think I'd need to belt a silencer into the straight pipe, which would then scrape on the floor, so it would probably be more agro than just building one from scratch. I bet it sounds lovely with the cats still in though! GLWTS