diff --git a/src/audio/include/stream_info.hpp b/src/audio/include/stream_info.hpp
index d31e035c..7cf9e847 100644
--- a/src/audio/include/stream_info.hpp
+++ b/src/audio/include/stream_info.hpp
@@ -16,6 +16,7 @@
 #include <utility>
 #include <variant>
 
+#include "esp_heap_caps.h"
 #include "freertos/FreeRTOS.h"
 #include "freertos/ringbuf.h"
 #include "freertos/stream_buffer.h"
@@ -110,6 +111,7 @@ class OutputStream;
 class RawStream {
  public:
   explicit RawStream(std::size_t size);
+  RawStream(std::size_t size, uint32_t);
   ~RawStream();
 
   auto info() -> StreamInfo& { return info_; }
diff --git a/src/audio/sink_mixer.cpp b/src/audio/sink_mixer.cpp
index 072dc9b7..79e6f3d3 100644
--- a/src/audio/sink_mixer.cpp
+++ b/src/audio/sink_mixer.cpp
@@ -20,11 +20,11 @@
 
 static constexpr char kTag[] = "mixer";
 
-static constexpr std::size_t kSourceBufferLength = 4 * 1024;
-static constexpr std::size_t kInputBufferLength = 4 * 1024;
-static constexpr std::size_t kReformatBufferLength = 4 * 1024;
+static constexpr std::size_t kSourceBufferLength = 2 * 1024;
+static constexpr std::size_t kInputBufferLength = 2 * 1024;
+static constexpr std::size_t kReformatBufferLength = 8 * 1024;
 static constexpr std::size_t kResampleBufferLength = kReformatBufferLength;
-static constexpr std::size_t kQuantisedBufferLength = 2 * 1024;
+static constexpr std::size_t kQuantisedBufferLength = 1 * 1024;
 
 namespace audio {
 
@@ -35,8 +35,8 @@ SinkMixer::SinkMixer(StreamBufferHandle_t dest)
       source_(xStreamBufferCreate(kSourceBufferLength, 1)),
       sink_(dest) {
   input_stream_.reset(new RawStream(kInputBufferLength));
-  floating_point_stream_.reset(new RawStream(kReformatBufferLength));
-  resampled_stream_.reset(new RawStream(kResampleBufferLength));
+  floating_point_stream_.reset(new RawStream(kReformatBufferLength, MALLOC_CAP_SPIRAM));
+  resampled_stream_.reset(new RawStream(kResampleBufferLength, MALLOC_CAP_SPIRAM));
 
   quantisation_buffer_ = {
       reinterpret_cast<std::byte*>(heap_caps_malloc(
diff --git a/src/audio/stream_info.cpp b/src/audio/stream_info.cpp
index 6efe297e..749e880e 100644
--- a/src/audio/stream_info.cpp
+++ b/src/audio/stream_info.cpp
@@ -30,6 +30,14 @@ RawStream::RawStream(std::size_t size)
   assert(buffer_ != NULL);
 }
 
+RawStream::RawStream(std::size_t size, uint32_t caps)
+    : info_(),
+      buffer_size_(size),
+      buffer_(reinterpret_cast<std::byte*>(
+          heap_caps_malloc(size, caps))) {
+  assert(buffer_ != NULL);
+}
+
 RawStream::~RawStream() {
   heap_caps_free(buffer_);
 }