diff --git a/hosts/common/programs/mpv/default.nix b/hosts/common/programs/mpv/default.nix
index 5466034a0..271317cfc 100644
--- a/hosts/common/programs/mpv/default.nix
+++ b/hosts/common/programs/mpv/default.nix
@@ -41,6 +41,7 @@
 
 let
   cfg = config.sane.programs.mpv;
+  myHrtf = "${pkgs.sofacoustics.listen.irc_1052}/share/sofa/listen-irc_1052.sofa";
   uosc = pkgs.mpvScripts.uosc.overrideAttrs (upstream: {
     version = "5.2.0-unstable-2024-03-13";
     src = lib.warnIf (lib.versionOlder "5.2.0" upstream.version) "uosc outdated; remove patch?" pkgs.fetchFromGitHub {
@@ -144,6 +145,8 @@ in
         # i use enable52Compat in order to get `table.unpack`.
         # i think using `luajit` here instead of `lua` is optional, just i get better perf with it :)
         lua = pkgs.luajit.override { enable52Compat = true; self = lua; };
+        # ship a ffmpeg with sofa enabled, for surround-sound downmixing
+        ffmpeg = pkgs.ffmpeg-full;
       };
       scripts = [
         pkgs.mpvScripts.mpris
@@ -221,6 +224,7 @@ in
     fs.".config/mpv/scripts/sane_cast/main.lua".symlink.target = ./sane_cast/main.lua;
     fs.".config/mpv/scripts/sane_sysvol/main.lua".symlink.target = ./sane_sysvol/main.lua;
     fs.".config/mpv/scripts/sane_sysvol/non_blocking_popen.lua".symlink.target = ./sane_sysvol/non_blocking_popen.lua;
+    fs.".config/mpv/hrtf.sofa".symlink.target = myHrtf;
     fs.".config/mpv/input.conf".symlink.target = ./input.conf;
     fs.".config/mpv/mpv.conf".symlink.target = ./mpv.conf;
     fs.".config/mpv/script-opts/osc.conf".symlink.target = ./osc.conf;
diff --git a/hosts/common/programs/mpv/mpv.conf b/hosts/common/programs/mpv/mpv.conf
index 3618380b4..eebb09888 100644
--- a/hosts/common/programs/mpv/mpv.conf
+++ b/hosts/common/programs/mpv/mpv.conf
@@ -26,3 +26,10 @@ border=no
 # # with `ao-volume`, the max actually is 100.
 # # to go higher you'll have to use the system's native controls.
 # volume-max=100
+
+# libmysofa Head Related Transfer Function file to use to downmix surround -> stereo
+# for specifically my skull
+# see: <https://ffmpeg.org/ffmpeg-filters.html#sofalizer>
+# TODO: this maybe belongs in pipewire instead of mpv.
+# at least, provide a way to disable the downmixing, so i can still output 5.1 over HDMI?
+af=sofalizer=sofa=/home/colin/.config/mpv/hrtf.sofa