The ornamental design for a volumeadjuster, as shown and described.
FIG. 1 is a perspective view of a volume adjuster, embodying my new design;
FIG. 2 is a front elevation view thereof;
FIG. 3 is a rear elevation view thereof;
FIG. 4 is a top plan view thereof;
FIG. 5 is a bottom plan view thereof;
FIG. 6 is a right side elevation view thereof;
FIG. 7 is a left side elevation view thereof; and,
FIG. 8 is an alternate perspective view thereof, shown in use.
The broken line showing of devices in FIG. 8 is included for the purpose of illustrating environment of the design and forms no part of the claimed design.