1. The black solution application was done by Umesh Wankhede who fits speakers, amplifiers and woofers in cars. That's his job. I was too lazy to get the details. However, you could ring him up at 9561798637 and give him my reference. (While he is fluent in Marathi, I doubt if he is equally so in English. So, try Hindi. Preferably, ring him up either before 1000 hrs or after about 2000 hrs since he holds a day-time job at an accessory shop.) 2. Comparison with regular damping materials. I can't do that since I don't have experience with the regular damping materials. Perhaps someone in Pune, who has got the regular damping, can listen to my music and then advise you.