diff --git a/sdkconfig.common b/sdkconfig.common
index 7ae9aea2..45f21e9a 100644
--- a/sdkconfig.common
+++ b/sdkconfig.common
@@ -22,7 +22,6 @@ CONFIG_SPI_MASTER_IN_IRAM=y
 # CONFIG_TWAI_ERRATA_FIX_RX_FIFO_CORRUPT is not set
 # CONFIG_TWAI_ERRATA_FIX_LISTEN_ONLY_DOM is not set
 CONFIG_GPIO_CTRL_FUNC_IN_IRAM=y
-CONFIG_I2S_ISR_IRAM_SAFE=y
 # CONFIG_ETH_USE_ESP32_EMAC is not set
 # CONFIG_ETH_USE_SPI_ETHERNET is not set
 # CONFIG_ESP_EVENT_POST_FROM_ISR is not set
diff --git a/src/audio/audio_fsm.cpp b/src/audio/audio_fsm.cpp
index ba6e5ffe..0119855a 100644
--- a/src/audio/audio_fsm.cpp
+++ b/src/audio/audio_fsm.cpp
@@ -13,7 +13,9 @@
 
 #include "audio_sink.hpp"
 #include "bluetooth_types.hpp"
+#include "esp_heap_caps.h"
 #include "esp_log.h"
+#include "freertos/FreeRTOS.h"
 #include "freertos/portmacro.h"
 #include "freertos/projdefs.h"
 
@@ -192,20 +194,28 @@ void AudioState::react(const TogglePlayPause& ev) {
 
 namespace states {
 
+// Two seconds of samples for two channels, at a representative sample rate.
+constexpr size_t kDrainBufferSize = sizeof(sample::Sample) * 48000 * 4;
+static StreamBufferHandle_t sDrainBuffer;
+
 void Uninitialised::react(const system_fsm::BootComplete& ev) {
   sServices = ev.services;
 
-  constexpr size_t kDrainBufferSize =
-      drivers::kI2SBufferLengthFrames * sizeof(sample::Sample) * 2 * 8;
   ESP_LOGI(kTag, "allocating drain buffer, size %u KiB",
            kDrainBufferSize / 1024);
-  StreamBufferHandle_t stream = xStreamBufferCreateWithCaps(
-      kDrainBufferSize, sizeof(sample::Sample), MALLOC_CAP_DMA);
+
+  auto meta = reinterpret_cast<StaticStreamBuffer_t*>(
+      heap_caps_malloc(sizeof(StaticStreamBuffer_t), MALLOC_CAP_DMA));
+  auto storage = reinterpret_cast<uint8_t*>(
+      heap_caps_malloc(kDrainBufferSize, MALLOC_CAP_SPIRAM));
+
+  sDrainBuffer = xStreamBufferCreateStatic(
+      kDrainBufferSize, sizeof(sample::Sample), storage, meta);
 
   sFileSource.reset(
       new FatfsAudioInput(sServices->tag_parser(), sServices->bg_worker()));
-  sI2SOutput.reset(new I2SAudioOutput(stream, sServices->gpios()));
-  sBtOutput.reset(new BluetoothAudioOutput(stream, sServices->bluetooth(),
+  sI2SOutput.reset(new I2SAudioOutput(sDrainBuffer, sServices->gpios()));
+  sBtOutput.reset(new BluetoothAudioOutput(sDrainBuffer, sServices->bluetooth(),
                                            sServices->bg_worker()));
 
   auto& nvs = sServices->nvs();