SDL_mixer: fluidsynth: tweak some defaults.

SDL Commits
1 
From 63f2c5a21760e3f1ad406ec8a8b18c6346f204b3 Mon Sep 17 00:00:00 2001
From: "Ryan C. Gordon" <[EMAIL REDACTED]>
Date: Fri, 9 Jan 2026 14:06:34 -0500
Subject: [PATCH] fluidsynth: tweak some defaults.

Fixes #284.
---
 src/decoder_fluidsynth.c | 8 ++++++++
 1 file changed, 8 insertions(+)

diff --git a/src/decoder_fluidsynth.c b/src/decoder_fluidsynth.c
index 1c296275..d5bb502e 100644
--- a/src/decoder_fluidsynth.c
+++ b/src/decoder_fluidsynth.c
@@ -280,6 +280,14 @@ static bool SDLCALL FLUIDSYNTH_init_track(void *audio_userdata, SDL_IOStream *io
     fluidsynth.fluid_settings_setnum(tdata->settings, "synth.sample-rate", (double) spec->freq);
     fluidsynth.fluid_settings_getnum(tdata->settings, "synth.sample-rate", &samplerate);
 
+    // these settings were recommended as good defaults in https://github.com/libsdl-org/SDL_mixer/issues/284
+    fluidsynth.fluid_settings_setnum(tdata->settings, "synth.chorus.depth", 5.0);
+    fluidsynth.fluid_settings_setnum(tdata->settings, "synth.chorus.level", 0.35);
+    fluidsynth.fluid_settings_setnum(tdata->settings, "synth.reverb.damp", 0.4);
+    fluidsynth.fluid_settings_setnum(tdata->settings, "synth.reverb.level", 0.15);
+    fluidsynth.fluid_settings_setnum(tdata->settings, "synth.reverb.width", 4);
+    fluidsynth.fluid_settings_setnum(tdata->settings, "synth.reverb.room-size", 0.6);
+
     // let custom properties override anything we already set internally. You break it, you buy it!
     SDL_EnumerateProperties(adata->fluidsynth_props, SetCustomFluidsynthProperties, tdata);