I claim the ornamental design for a speaker, as shown and described.
FIG. 1 is a top front perspective view of a speaker of the present invention.
FIG. 2 is a bottom, rear perspective view of the speaker of FIG. 1.
FIG. 3 is a front elevation view of the speaker of FIG. 1.
FIG. 4 is a rear elevation view of the speaker of FIG. 1.
FIG. 5 is a side elevation view of the right side of the speaker of FIG. 1.
FIG. 6 is a side elevation view of the left side of the speaker of FIG. 1.
FIG. 7 is a top plan view of the speaker of FIG. 1.
FIG. 8 is a bottom plan view of the speaker of FIG. 1; and,
FIG. 9 is a side elevation view of the right side of an alternative arrangement of the speaker of FIG. 1 showing the ring on the top of the speaker in FIGS. 1-8 positioned on the bottom of the speaker and being used as a support for the speaker.
In the drawings, the broken lines depict portions of the speaker that form no part of the claimed design.