Add skull faceplate/grille raised over the speaker opening

skull.svg

@@ -0,0 +1,2 @@
+<!-- Skull: "death-skull" by sbed, from game-icons.net - CC BY 3.0 (https://creativecommons.org/licenses/by/3.0/). Background rect removed. -->
+<svg xmlns="http://www.w3.org/2000/svg" viewBox="0 0 512 512"><path fill="#fff" d="M255.997 16.004c-120 0-239.997 60-239.997 149.998C16 226.002 61 256 61 316c0 45-15 45-15 75 0 14.998 48.01 32.002 89.998 44.998v60h239.997v-60s90.567-27.957 90-45c-.933-27.947-15-30-15-74.998 0-30 45.642-91.42 44.998-149.998 0-90-119.998-149.998-239.996-149.998zm-90 179.997c33.137 0 60 26.864 60 60 0 33.136-26.863 60-60 60C132.863 316 106 289.136 106 256c0-33.136 26.862-60 59.998-60zm179.998 0c33.136 0 60 26.864 60 60 0 33.136-26.864 60-60 60-33.136 0-60-26.864-60-60 0-33.136 26.864-60 60-60zm-89.998 105c15 0 45 60 45 75 0 29.998 0 29.998-15 29.998h-60c-15 0-15 0-15-30 0-15 30-74.998 45-74.998z"/></svg>

speakerbox.scad

@@ -103,5 +103,66 @@ module hookBaseInside()
   speakerRetainer();
 }
 
+//---------------------------------------------------------------
+// Skull faceplate / grille
+//   A round faceplate, raised proud of the front face, that fully
+//   overlaps the 45mm speaker opening and fuses to the solid front
+//   wall around it. A skull face is cut through it as the speaker
+//   grille - eye sockets and nasal opening come straight from the
+//   icon, plus a row of added tooth slots in the jaw.
+//   skull.svg: "death-skull" by sbed / game-icons.net - CC BY 3.0
+//   https://game-icons.net/1x1/sbed/death-skull.html
+//---------------------------------------------------------------
+plateDia      = 50;    // faceplate diameter (> 45mm opening -> fused rim)
+plateRaise    = 2.6;   // mm proud of the front face
+plateEmbed    = 1.5;   // mm the plate sinks into the front wall (weld)
+skullFaceW    = 46;    // skull width across the plate
+skullMaskD    = 44;    // opened-up disc around the skull -> the grille voids
+frontOuterX   = shellInsideLength + 2*wallThickness;  // X of the outer front face
+speakerYc     = 27;    // speaker opening centre (Y)
+speakerZc     = 28.6;  // speaker opening centre (Z)
+
+// skull.svg imports at ~180.6mm wide (512-unit viewBox at 72dpi)
+skullImportW  = 180.6;
+
+module skullArt() { import("skull.svg", center = true); }
+
+// The faceplate is a solid disc. The grille is the skull's negative
+// space: inside a centre disc, everything that is NOT skull bone is
+// opened up - eye sockets, nasal opening and the crescent gaps around
+// the cranium and jaw. The bone itself stays as plate material, so the
+// disc is never cut through and the skull reads by its voids.
+module grille2D()
+{
+  difference()
+  {
+    circle(d = plateDia, $fn = 160);
+    difference()
+    {
+      circle(d = skullMaskD, $fn = 150);
+      scale(skullFaceW / skullImportW) skullArt();
+    }
+    // teeth: a row of slots cut into the jaw for extra grille area
+    for (i = [-2 : 2])
+      translate([i * 4.4, -15.5]) square([2.2, 7], center = true);
+  }
+}
+
+module skullFaceplate()
+{
+  // hookBaseOutside() shares the inner-corner origin:
+  //   global = hookCoord + [wallThickness, wallThickness, basePlaneThickness]
+  translate([-wallThickness, -wallThickness, -basePlaneThickness])
+    translate([frontOuterX - plateEmbed, speakerYc, speakerZc])
+      rotate([90, 0, 90])            // 2D x->Y, 2D y->Z, extrude->+X
+        linear_extrude(plateRaise + plateEmbed)
+          grille2D();
+}
+
+module hookBaseOutside()
+{
+  skullFaceplate();
+}
+
 showOrientation = true;
 YAPPgenerate();