The ornamental design for a fitting for racks for attaching sound effect devices, as shown.
FIG. 1 is a perspective view of fitting for racks for attaching sound effect devices;
FIG. 2 is a front view of fitting for racks for attaching sound effect devices;
FIG. 3 is a rear view of fitting for racks for attaching sound effect devices;
FIG. 4 is a top view of fitting for racks for attaching sound effect devices;
FIG. 5 is a bottom view of fitting for racks for attaching sound effect devices;
FIG. 6 is a left-side view of fitting for racks for attaching sound effect devices; and,
FIG. 7 is a right-side view of fitting for racks for attaching sound effect devices.
The broken lines in FIGS. 5 and 7 illustrate portions of the fitting for racks for attaching sound effect devices that form no part of the claimed design.