Adjust default offsets based on bass operational mode

osu.Game/Beatmaps/FramedBeatmapClock.cs

@@ -5,12 +5,14 @@
 using System.Diagnostics;
 using osu.Framework;
 using osu.Framework.Allocation;
+using osu.Framework.Audio;
 using osu.Framework.Bindables;
 using osu.Framework.Graphics;
 using osu.Framework.Timing;
 using osu.Game.Configuration;
 using osu.Game.Database;
 using osu.Game.Screens.Play;
+using Vulkan.Xlib;
 
 namespace osu.Game.Beatmaps
 {
@@ -44,6 +46,8 @@ public partial class FramedBeatmapClock : Component, IFrameBasedClock, IAdjustab
 
         private readonly DecouplingFramedClock decoupledTrack;
 
+        private IBindable<bool>? usingGlobalMixer;
+
         [Resolved]
         private OsuConfigManager config { get; set; } = null!;
 
@@ -69,7 +73,7 @@ public FramedBeatmapClock(bool applyOffsets, bool requireDecoupling, IClock? sou
             {
                 // Audio timings in general with newer BASS versions don't match stable.
                 // This only seems to be required on windows. We need to eventually figure out why, with a bit of luck.
-                platformOffsetClock = new OffsetCorrectionClock(interpolatedTrack, ExternalPauseFrequencyAdjust) { Offset = RuntimeInfo.OS == RuntimeInfo.Platform.Windows ? 15 : 0 };
+                platformOffsetClock = new OffsetCorrectionClock(interpolatedTrack, ExternalPauseFrequencyAdjust);
 
                 // User global offset (set in settings) should also be applied.
                 userGlobalOffsetClock = new OffsetCorrectionClock(platformOffsetClock, ExternalPauseFrequencyAdjust);
@@ -83,6 +87,23 @@ public FramedBeatmapClock(bool applyOffsets, bool requireDecoupling, IClock? sou
             }
         }
 
+        [BackgroundDependencyLoader]
+        private void load(AudioManager audioManager)
+        {
+            if (platformOffsetClock != null)
+            {
+                if (RuntimeInfo.OS == RuntimeInfo.Platform.Windows)
+                {
+                    usingGlobalMixer = audioManager.UsingGlobalMixer.GetBoundCopy();
+                    usingGlobalMixer.BindValueChanged(usingMixer =>
+                    {
+                        // known "good" values, aka defaults which work for the majority of users.
+                        platformOffsetClock.Offset = usingMixer.NewValue ? -35 : 15;
+                    });
+                }
+            }
+        }
+
         protected override void LoadComplete()
         {
             base.LoadComplete();