I claim, the ornamental design for a portable audio-driven fire pit, as shown and described.
FIG. 1 is a perspective view of my design.
FIG. 2 is a front elevation view of my design.
FIG. 3 is a back elevation view of my design.
FIG. 4 is a left side elevation view of my design.
FIG. 5 is a right side elevation view of my design; and,
FIG. 6 is a top view of my design.
The broken lines showing portions of the portable audio-driven figure pit is for the purpose of illustrating environmental structure and forms no part of the claimed design.