Choosing a Marimba
Types of mallets and mallet selection

Tone-plate percussion instruments are played by hitting with mallets. Different mallets are suited to different instruments, depending on combinations of head material and hardness, as well as of bulb size. If a mallet with a hard head were to be used with a marimba or another instrument with wooden tone plates, the tone plates could be damaged. Therefore, it is crucial to select mallets that are appropriate for the way in which the instrument is to be played.
The heads of tone-plate percussion instruments' mallets are primarily made of the following materials:

Rubber

This material is used for a wide variety of instruments. Hard rubber is suited to instruments such as the glockenspiel and the xylophone, while soft rubber is suited to the marimba.

Rosewood, Hytrel, Lexan, and ABS resin

These materials are suited to the glockenspiel and the xylophone. Combinations of these materials and different sizes give rise to a rich variety of hard sounds. Lexan produces a well-rounded timbre, and ABS resin produces a light, bright timbre. Hytrel has a somewhat light touch, with a hardness that allows it be used without any risk when playing instruments with wooden tone plates.

Yarn wrapping

A head made from a rubber bulb with yarn wrapped around it. Such heads are characterized by their mellow timber, making them ideal for the marimba. They are also used for the xylophone and the vibraphone.

Cotton yarn wrapping

Cotton yarn is somewhat harder than ordinary wool yarn, and it is characterized by its bright and crisp timbre. It is suited to the vibraphone and to metallophones.

The mallet heads suited to the marimba are either soft rubber bulbs or rubber bulbs wrapped in wool yarn. Of these heads, there is some variation in the hardness of the rubber bulbs. The hardness of the mallet head is the biggest factor that influences the hardness or softness of the sounds, so you should try various mallets and find some that suit you.

Mallets wrapped in wool yarn and those that have naked rubber bulbs tend to have the following characteristics:

Yarn-wrapped type

Because the rubber bulb collides with the tone plates with a layer of yarn in between them, the sound of the strike is softened, producing a relatively deep timbre that melds with the sounds of other instruments.

Type with the rubber bulb exposed

Because the rubber bulb directly impacts the tone plates, there is a clear striking sound when the mallet head touches a tone plate, which is relatively noticeable. The timbre stands out among the sounds of other instruments.

Therefore, perhaps the yarn-wrapped type would be best suited to such instances as when you want to produce the characteristic depth of timbre of the marimba and when you want the sound to meld with the rest of ensemble, and the type with the exposed rubber bulb would be best suited to cases such as when you want to play a melody in a xylophone-esque way and when you want the sound to stand out.
In any case, the selection of mallets is crucial to maximizing the performance of your marimba.

If you select soft mallets for lower notes and relatively hard mallets for higher notes and use each type of mallet, accordingly, the right timbre for each sound range will be produced. However, because of the extreme thinness of the tone plates in the low ranges because of the way in which those notes are tuned, there is a risk that the use of a too-hard mallet will cause tone plates to break, so care must be taken.

If there is a chance that you may play with four mallets of the same model number, it is recommended that you buy all four at once. This is because mallets' timbres change the more they are played. For instance, if you purchased two, played using them for some time, and then bought two more mallets of the same model number, the qualities of the sounds produced by the four might not match. It would perhaps be wise to avoid buying extra mallets of the same model number later, if possible.

When yarn-wrapped mallets are used thoroughly, the yarn is gradually damaged. Mallets with damaged yarn may be able to be fixed by rewrapping them. If repair is possible, then it will be cheaper than purchasing a replacement. It might be a good idea to consult the music store from which you purchased the mallet.