Finally able to post a couple of comparison figures.

These numbers were sent to me by a customer with a Career 707 .25 caliber air gun who asked me if I could make him an LDC that was quieter than his Wolf LDC. I responded that I had no idea since I have no idea what kind of sound reduction a Wolf or any other makers LDC will give. He went ahead and asked me to make him one and below are the figures he sent to me, they are taken by my customer not by me and should be unbiased. Take them how you will, without running the tests myself I can not vouch for the numbers. It is good when customers do take the time to send comparison figures to makers as it tells us if out product is working well or needs more refining, Even if they are not accurate they still give me some idea of how well my product is working, or not working, Neil.

"I did some testing with a sound meter. Your LDC delivered a 20db improvement over a Wolf. A 35 db improvement over a 1.25. Anthony Storey and a 30db improvement over a 1.5" Anthony Storey. I made an M14 x 1.25 to 10mm x 1 adapter and tested it with the Cricket too. It delivered a 10db improvement although it's obviously a fair but wider and heavier as it was made for a more powerful air rifle. I made a carbon fiber tube to cover the space when the shroud normally is and it looks good in the carbon fiber stock I'm making." 

Again I can not vouch for these numbers, these are numbers given to me by my customer and I have no idea how the tests were performed or how accurate they are, Neil.