diff --git a/src/backend/mod.rs b/src/backend/mod.rs
index 6ca25437..8f0f079f 100644
--- a/src/backend/mod.rs
+++ b/src/backend/mod.rs
@@ -817,14 +817,14 @@ fn get_default_device_id(devtype: DeviceType) -> std::result::Result<AudioObject
     }
 }
 
-fn audiounit_convert_channel_layout(layout: &AudioChannelLayout) -> Vec<mixer::Channel> {
+fn audiounit_convert_channel_layout(layout: &AudioChannelLayout) -> Result<Vec<mixer::Channel>> {
     if layout.mChannelLayoutTag != kAudioChannelLayoutTag_UseChannelDescriptions {
         // kAudioChannelLayoutTag_UseChannelBitmap
         // kAudioChannelLayoutTag_Mono
         // kAudioChannelLayoutTag_Stereo
         // ....
         cubeb_log!("Only handling UseChannelDescriptions for now.\n");
-        return Vec::new();
+        return Err(Error::error());
     }
 
     let channel_descriptions = unsafe {
@@ -840,10 +840,10 @@ fn audiounit_convert_channel_layout(layout: &AudioChannelLayout) -> Vec<mixer::C
         channels.push(label.into());
     }
 
-    channels
+    Ok(channels)
 }
 
-fn audiounit_get_preferred_channel_layout(output_unit: AudioUnit) -> Vec<mixer::Channel> {
+fn audiounit_get_preferred_channel_layout(output_unit: AudioUnit) -> Result<Vec<mixer::Channel>> {
     let mut rv = NO_ERR;
     let mut size: usize = 0;
     rv = audio_unit_get_property_info(
@@ -859,7 +859,7 @@ fn audiounit_get_preferred_channel_layout(output_unit: AudioUnit) -> Vec<mixer::
             "AudioUnitGetPropertyInfo/kAudioDevicePropertyPreferredChannelLayout rv={}",
             rv
         );
-        return Vec::new();
+        return Err(Error::error());
     }
     debug_assert!(size > 0);
 
@@ -877,7 +877,7 @@ fn audiounit_get_preferred_channel_layout(output_unit: AudioUnit) -> Vec<mixer::
             "AudioUnitGetProperty/kAudioDevicePropertyPreferredChannelLayout rv={}",
             rv
         );
-        return Vec::new();
+        return Err(Error::error());
     }
 
     audiounit_convert_channel_layout(layout.as_ref())
@@ -885,7 +885,7 @@ fn audiounit_get_preferred_channel_layout(output_unit: AudioUnit) -> Vec<mixer::
 
 // This is for output AudioUnit only. Calling this by input-only AudioUnit is prone
 // to crash intermittently.
-fn audiounit_get_current_channel_layout(output_unit: AudioUnit) -> Vec<mixer::Channel> {
+fn audiounit_get_current_channel_layout(output_unit: AudioUnit) -> Result<Vec<mixer::Channel>> {
     let mut rv = NO_ERR;
     let mut size: usize = 0;
     rv = audio_unit_get_property_info(
@@ -901,8 +901,7 @@ fn audiounit_get_current_channel_layout(output_unit: AudioUnit) -> Vec<mixer::Ch
             "AudioUnitGetPropertyInfo/kAudioUnitProperty_AudioChannelLayout rv={}",
             rv
         );
-        // This property isn't known before macOS 10.12, attempt another method.
-        return audiounit_get_preferred_channel_layout(output_unit);
+        return Err(Error::error());
     }
     debug_assert!(size > 0);
 
@@ -920,7 +919,7 @@ fn audiounit_get_current_channel_layout(output_unit: AudioUnit) -> Vec<mixer::Ch
             "AudioUnitGetProperty/kAudioUnitProperty_AudioChannelLayout rv={}",
             rv
         );
-        return Vec::new();
+        return Err(Error::error());
     }
 
     audiounit_convert_channel_layout(layout.as_ref())
@@ -2860,20 +2859,57 @@ impl<'ctx> CoreStreamData<'ctx> {
                 e
             })?;
 
-            // XXX
-            let device_layout = if using_voice_processing_unit {
-                let mut channels = Vec::with_capacity(output_hw_desc.mChannelsPerFrame as usize);
-                match output_hw_desc.mChannelsPerFrame {
-                    1 => channels.push(mixer::Channel::FrontCenter),
-                    _ => {
-                        channels.push(mixer::Channel::FrontLeft);
-                        channels.push(mixer::Channel::FrontRight);
+            let device_layout = audiounit_get_current_channel_layout(self.unit)
+                .or_else(|_| {
+                    // The VoiceProcessingIO unit is known to not support
+                    // kAudioUnitProperty_AudioChannelLayout queries. If we're using
+                    // VoiceProcessingIO, try standing up a regular AudioUnit and query that.
+                    if !using_voice_processing_unit {
+                        return Err(Error::error());
                     }
-                }
-                channels
-            } else {
-                audiounit_get_current_channel_layout(self.unit)
-            };
+                    cubeb_log!(
+                        "({:p}) Could not get current channel layout for vpio unit. \
+                         Retrying with a dedicated unit.",
+                        self.stm_ptr
+                    );
+                    let mut blank_in_dev_info = self.input_device.clone();
+                    blank_in_dev_info.flags = device_flags::DEV_UNKNOWN;
+                    let mut dedicated_unit = create_audiounit(&blank_in_dev_info, &self.output_device)?;
+                    let res = audiounit_get_current_channel_layout(dedicated_unit).or_else(|_| {
+                        cubeb_log!(
+                            "({:p}) Could not get current channel layout for dedicated unit. \
+                             Trying to get preferred channel layout with the dedicated unit.",
+                             self.stm_ptr
+                        );
+                        audiounit_get_preferred_channel_layout(dedicated_unit)
+                    });
+                    audio_unit_uninitialize(dedicated_unit);
+                    dispose_audio_unit(dedicated_unit);
+                    dedicated_unit = ptr::null_mut();
+                    res
+                })
+                .or_else(|_| {
+                    // The kAudioUnitProperty_AudioChannelLayout property isn't known before
+                    // macOS 10.12, attempt another method.
+                    cubeb_log!(
+                        "({:p}) Could not get current channel layout. Trying preferred channel layout.",
+                        self.stm_ptr
+                    );
+                    audiounit_get_preferred_channel_layout(self.unit)
+                })
+                .unwrap_or_else(|_| {
+                    cubeb_log!(
+                        "({:p}) Could not get any channel layout. Defaulting to no channels.",
+                        self.stm_ptr
+                    );
+                    Vec::new()
+                });
+
+            cubeb_log!(
+                "({:p} Using output device channel layout {:?}",
+                self.stm_ptr,
+                device_layout
+            );
 
             // The mixer will be set up when
             // 1. using aggregate device whose input device has output channels
diff --git a/src/backend/tests/api.rs b/src/backend/tests/api.rs
index 1ee450a1..dd3f94f3 100644
--- a/src/backend/tests/api.rs
+++ b/src/backend/tests/api.rs
@@ -700,7 +700,7 @@ fn test_convert_channel_layout() {
         }
         let layout_ref = unsafe { &(*(&layout as *const TestLayout as *const AudioChannelLayout)) };
         assert_eq!(
-            &audiounit_convert_channel_layout(layout_ref),
+            &audiounit_convert_channel_layout(layout_ref).unwrap(),
             expected_layout
         );
     }
@@ -711,7 +711,9 @@ fn test_convert_channel_layout() {
 #[test]
 fn test_get_preferred_channel_layout_output() {
     match test_get_default_audiounit(Scope::Output) {
-        Some(unit) => assert!(!audiounit_get_preferred_channel_layout(unit.get_inner()).is_empty()),
+        Some(unit) => assert!(!audiounit_get_preferred_channel_layout(unit.get_inner())
+            .unwrap()
+            .is_empty()),
         None => println!("No output audiounit for test."),
     }
 }
@@ -721,7 +723,9 @@ fn test_get_preferred_channel_layout_output() {
 #[test]
 fn test_get_current_channel_layout_output() {
     match test_get_default_audiounit(Scope::Output) {
-        Some(unit) => assert!(!audiounit_get_current_channel_layout(unit.get_inner()).is_empty()),
+        Some(unit) => assert!(!audiounit_get_current_channel_layout(unit.get_inner())
+            .unwrap()
+            .is_empty()),
         None => println!("No output audiounit for test."),
     }
 }