The ornamental design for a handle for speaker, as shown and described.
FIG. 1 is a front, top and right side perspective view of a handle for speaker, showing my new design;
FIG. 2 is a front view thereof;
FIG. 3 is a rear view thereof;
FIG. 4 is a right side view thereof,
FIG. 5 is a top view thereof;
FIG. 6 is a bottom view thereof; and,
FIG. 7 is a cross sectional view at 9-9 shown in FIG. 2.
The left side view is a mirror image of the right side view.
The broken line showing of the handle for speaker is included for the purpose of illustrating portions of the handle for speaker and forms no part of the claimed design.