All this is well and good advice....maybe its just my tin-brass earballs...but haven't you SILENT BRASS HEADS noticed a pretty sizable change in the quality of sound production and especially the intonation...IF THE SILENT BRASS MUTE IS JAMMED IN TOO TIGHTLY? This has been an issue for me ever since the first moments that I hooked that Silent Brass system into our sound unit at church to the point that I simply had to play with the mute lightly held into the bell and supported with just my left hand, to stay in pitch center with the choir and other musicians. Natually this left most of the weighted SILENT BRASS support, mostly onto my right hand, which was holding the trumpet. (might require some weight training if the trumpet happens to be one of those heavier weight models....ala'Monette..etc.) SILENT BRASS...just plain doesn't pitch or play consistantly when JAMMED IN TOO TIGHTLY. ALSO....I have made a life long habit of playing all of my mutes pretty much lightly inserted into the bell, leaving most of the support with my left hand holding the SBmute...which on some of those heavier copper ala'Joral bubbleee's can be pretty much of a workout... Especially on those long nightee-nighter gigs from hell in a mute basket. Bottom line: I think ALL MUTES just play and sound better if NOT INSERTED TOO TIGHTLY? At least that is what my old mentor the late Jake' Jacoby taught us about using mutes. (Nothing interupts playing quality music faster,than a mute that is inserted and jammed in too tightly. I JUST HATE WHEN THAT HAPPENS when suddenly your mute parts company with the bell of your horn....n' "falls out onto the floor and rolls down into the audience. FUNNY STUFF, HUH? WE'VE ALL BEEN THERE...DUNNNN-DUDE DAT?? Last and again very butt bottom line: PRACTICE...PRACTICE...PRACTICE...it has always astounded me that so many gifted trumpet players are sooooo nerd-de-well, are so lacking n' out of practicing consitantly when it comes to working with mutes?