We claim the ornamental design for a speaker, as shown and described.
FIG. 1 is a front perspective view of a speaker.
FIG. 2 is a front view of a speaker.
FIG. 3 is a rear view of a speaker.
FIG. 4 is a top view of a speaker.
FIG. 5 is a bottom view of a speaker.
FIG. 6 is a left side view of a speaker.
FIG. 7 is a right side view of a speaker; and,
FIG. 8 cross sectional view taken along the lines 8—8 on FIG. 2 which omits a portion of the internal structure of a speaker.
The ornamental design which is claimed is shown in solid lines in the drawings. The broken lines in the drawings are for illustrative purposes only and form no part of the claimed design. FIG. 8 provides an A—A cross-sectional taken along a line A—A shown in the front view of FIG. 2, and illustrates a state of the internal structure with a portion thereof being omitted. The A—A line shown in the front view of FIG. 2 does not constitute the design.