diff --git a/modules/nixos/system/nix/default.nix b/modules/nixos/system/nix/default.nix
index 8773afa..f005c2e 100644
--- a/modules/nixos/system/nix/default.nix
+++ b/modules/nixos/system/nix/default.nix
@@ -43,14 +43,14 @@ in
             "flakes"
           ];
 
-          # Set up secondary binary caches for Lix and Hevana
+          # Set up Hevana and Lix as secondary binary caches
           substituters = [
-            "https://cache.lix.systems"
             "https://${config.${namespace}.secrets.services.binary-cache.url}"
+            "https://cache.lix.systems"
           ];
           trusted-public-keys = [
-            "cache.lix.systems:aBnZUw8zA7H35Cz2RyKFVs3H4PlGTLawyY5KRbvJR8o="
             config.${namespace}.secrets.services.binary-cache.pubcert
+            "cache.lix.systems:aBnZUw8zA7H35Cz2RyKFVs3H4PlGTLawyY5KRbvJR8o="
           ];
 
           # Authentication for Hevana's binary cache
diff --git a/systems/aarch64-linux/Pihole/hardware-configuration.nix b/systems/aarch64-linux/Pihole/hardware-configuration.nix
index 3ed2235..09425f1 100644
--- a/systems/aarch64-linux/Pihole/hardware-configuration.nix
+++ b/systems/aarch64-linux/Pihole/hardware-configuration.nix
@@ -3,16 +3,25 @@
 {
   lib,
   modulesPath,
-  namespace,
   ...
 }:
 
 {
   imports = [ (modulesPath + "/installer/scan/not-detected.nix") ];
 
-  boot.loader = lib.mkForce {
-    grub.enable = false;
-    generic-extlinux-compatible.enable = true;
+  boot = {
+    # Enable audio devices
+    kernelParams = [
+      "snd_bcm2835.enable_hdmi=1"
+      "snd_bcm2835.enable_headphones=1"
+      "dtparam=audio=on"
+    ];
+
+    # Configure bootloader
+    loader = lib.mkForce {
+      grub.enable = false;
+      generic-extlinux-compatible.enable = true;
+    };
   };
 
   #boot.kernelParams = [
@@ -35,11 +44,9 @@
     enableRedistributableFirmware = true;
     raspberry-pi."4" = {
       apply-overlays-dtmerge.enable = true;
+      fkms-3d.enable = true; # Enable GPU
     };
 
-    deviceTree = {
-      enable = true;
-      filter = "*rpi-4-*.dtb";
-    };
+    deviceTree.enable = true;
   };
 }