I claim the ornamental design for the passive acoustic amplifier for multi-media devices, as shown and described.
FIG. 1 is a perspective view of a passive acoustic amplifier for a multi-media device showing my new design;
FIG. 2 is a front view thereof;
FIG. 3 is a back view thereof;
FIG. 4 is a right-side view with the left side being a mirror image thereof;
FIG. 5 is a top view thereof;
FIG. 6 is a bottom view thereof;
FIG. 7 is a front view, identical to FIG. 2, with an additional broken line rectangle representing a multi-media device in a upright or vertical position placed on the device and is for illustrative purposes only; and,
FIG. 8 is a front view, identical to FIG. 2, with an additional broken line rectangle representing a multi-media device in a horizon position placed on the device and is for illustrative purposes only.