Refactor sound card config

hosts/odyssey/default.nix

@@ -4,6 +4,7 @@ with lib.my;
 {
   imports = [
     ./hardware-configuration.nix
+    ./audio.nix
     ../desktop.nix
   ];
 
@@ -16,32 +17,8 @@ with lib.my;
 
   networking.hostName = "odyssey";
   networking.hostId = "c5e68d78";
-
   networking.networkmanager.enable = true;
 
-  environment.etc."pipewire/pipewire.conf.d/surround.conf".text = ''
-    context.modules = [
-      {
-        name = libpipewire-module-loopback
-        args = {
-          node.description = "1824c Surround"
-          capture.props = {
-            node.name = "1824c_Speakers"
-            media.class = "Audio/Sink"
-            audio.position = [ FL FR SL SR LFE ]
-          }
-          playback.props = {
-            node.name = "playback.1824c_Speakers"
-            audio.position = [ AUX0 AUX1 AUX3 AUX4 AUX5 ]
-            target.object = "alsa_output.usb-PreSonus_Studio_1824c_SC4E21110775-00.multichannel-output"
-            stream.dont-remix = true
-            node.passive = true
-          }
-        }
-      }
-    ]
-  '';
-
   nix.package = pkgs.nixFlakes;
   nix.extraOptions = ''
     experimental-features = nix-command flakes