^^
Yea that's what I did for a while but the Gehmann trap is still more convenient. Earmuffs solve the noise problem and placing some duct seal on the back of the steel plate will dull the sound. Hey, at least I KNOW I'm lazy!
Actually I'm not the only one who hates the "clang". A loud sound such as that can trigger instant massive migraines in my wife ... so keeping the noise level down is always something we deal with around my home.
Duct seal on the back of the plate is a good idea, that would definitely help.
A polythene cutting board at 45 degrees makes a very quiet backstop...after all ,HD polythene is what many ballistic inserts are made of... Very cheap at $ stores