These two Joral Bubble mutes are an update to the classic Harmon wa-wa design. Their slightly heavier weight and larger resonating chamber allows a full, richer tone and additional projection compared to the Harmon. For the mute aficionado, there is room for both in your arsenal.
Aluminum: More presence than Harmon, louder sound.
Copper: All copper wa-wa, quite a bit heavier than the aluminum version.
The unique bubble shape seems to help this wah-wah mute have fewer intonation problems than other models which tend to play somewhat sharp. The aluminum version has the characteristic, "pithy" timbre that is effective in solo and ensemble situations.