The ornamental design for a sofabases, as shown and described.
FIG. 1 is a front perspective view of two sofa bases, a sofa bases;
FIG. 2 is a front view of the two sofa bases, the left sofa base is on the left side of the page, and the right sofa base is on the right side of the page;
FIG. 3 is a rear view of the two sofa bases;
FIG. 4 is a left side view of the right sofa base;
FIG. 5 is a top view of the two sofa bases;
FIG. 6 is a perspective view of the two sofa bases attached to a first embodiment of a sofa; and,
FIG. 7 is a perspective view of the two sofa bases attached to a second embodiment of a sofa.
The broken lines in FIGS. 1, 5, 6, and 7 representing fastener holes in the sofa bases and the broken lines in FIGS. 6 and 7 representing the sofas, show the design as being used, and form no part of the claimed design.