I had to do a Miles Davis soundalike recording this week. Specifically I had to try and reproduce his 1980's muted sound. For these records he was using a harmon mute and I have seen some debate about which brand of mute to use. After a bit of experimenting I think the issue is more to do with mouthpiece choice and processing of the final audio. I experimented with various mouthpieces and my Denis Wick harmon mute and found that the closest was a quite deep Warbrton 3MD with a very large no 12 backbore. Even this was still not quite like the records so I equalised the sound to bring up the bass. See what you think, but I think its pretty close to the timbre of sound Miles Davis was producing in the 1980's:
