This week I had been looking for notched sound profiles for digitrax sound decoders (my SD38-2 has digitrax sound). I knew it was possible to do notching but the supplied SD38 sound profile did not do it.
Eventually I stumbled on to some files in the digitraxsound yahoo group where I found notched projects for the EMD 567 non-turbo, 645 non-turbo, and 645 with turbo. The 645 NT was correct for my prototype so I downloaded it to my SD38 this afternoon and I have to say it is a very nice improvement over the factory SD38 sound. The 645 projects were by Alex Stroshane and I have to say thanks to him for the great profile!