A few minor mingw workarounds.

modules/juce_audio_devices/native/juce_win32_ASIO.cpp

@@ -1407,12 +1407,6 @@ private:
         }
     };
 
-    template <>
-    struct ASIOCallbackFunctions <sizeof(currentASIODev) / sizeof(currentASIODev[0])>
-    {
-        static void setCallbacksForDevice (ASIOCallbacks&, ASIOAudioIODevice*) noexcept {}
-    };
-
     void setCallbackFunctions() noexcept
     {
         ASIOCallbackFunctions<0>::setCallbacksForDevice (callbacks, this);
@@ -1421,6 +1415,12 @@ private:
     JUCE_DECLARE_NON_COPYABLE_WITH_LEAK_DETECTOR (ASIOAudioIODevice)
 };
 
+template <>
+struct ASIOAudioIODevice::ASIOCallbackFunctions <sizeof(currentASIODev) / sizeof(currentASIODev[0])>
+{
+    static void setCallbacksForDevice (ASIOCallbacks&, ASIOAudioIODevice*) noexcept {}
+};
+
 //==============================================================================
 class ASIOAudioIODeviceType  : public AudioIODeviceType
 {

modules/juce_audio_devices/native/juce_win32_WASAPI.cpp

@@ -112,6 +112,11 @@ bool check (HRESULT hr)
  #define JUCE_COMCLASS(name, guid)       struct __declspec (uuid (guid)) name
 #endif
 
+#if JUCE_MINGW && defined (KSDATAFORMAT_SUBTYPE_PCM)
+ #undef KSDATAFORMAT_SUBTYPE_PCM
+ #undef KSDATAFORMAT_SUBTYPE_IEEE_FLOAT
+#endif
+
 #ifndef KSDATAFORMAT_SUBTYPE_PCM
  #define KSDATAFORMAT_SUBTYPE_PCM         uuidFromString ("00000001-0000-0010-8000-00aa00389b71")
  #define KSDATAFORMAT_SUBTYPE_IEEE_FLOAT  uuidFromString ("00000003-0000-0010-8000-00aa00389b71")