Having a practice mute comes very handy especially when you live in an apartment building or practice late at night. I have been testing two of the most popular practice mutes: the one made of metal and another one made of rubber.
Make sure to place this mute right on top of the bridge gently pushing it down. Don’t force it.
Playing with this metal mute will let you achieve near silent and clear tone, but you have to be very careful because this mute can fall off the bridge quite easily damaging your instrument. It fell off my violin quite a few times while practicing especially forte passages. Also if you are a passionate player and move a lot during practice you can expect this mute to fly off, since vibrations of the strings will cause this mute to get loose on the bridge.
Keep in mind that because of its weight, metal practice mute can also damage your bridge if it is used excessively.
The rubber mute on the other hand is extremely safe to use but not as effective as the metal one.
Using the rubber mute will not muffle the sound as much as the heavy metal mute does, but does work quite well. Make sure to push the rubber mute all the way down to the bridge. If you place it right on top, it just won’t work.
I like the fact that the rubber mute will never damage or fall off your bridge. It is very light weight. You can pretty much dance with your violin and this mute will always stay in place. The tone quality is different from the metal mute. The sound appears to be deeper and richer but is not as clear as the one on the metal mute especially on the G and D string.
In my opinion both mutes will do the job just fine. You have to pick what best will work for you. Rubber mute is care and worry free. Metal mute is more effective but you will have to be extremely careful using it.