diff --git a/misc_modules/recorder/src/main.cpp b/misc_modules/recorder/src/main.cpp
index 25287518..238c83a3 100644
--- a/misc_modules/recorder/src/main.cpp
+++ b/misc_modules/recorder/src/main.cpp
@@ -7,6 +7,7 @@
 #include <dsp/sink/handler_sink.h>
 #include <dsp/routing/splitter.h>
 #include <dsp/audio/volume.h>
+#include <dsp/convert/stereo_to_mono.h>
 #include <thread>
 #include <ctime>
 #include <gui/gui.h>
@@ -41,15 +42,15 @@ public:
         root = (std::string)core::args["root"];
 
         // Define option lists
-        formats.define("WAV", wav::FORMAT_WAV);
-        // formats.define("RF64", wav::FORMAT_RF64); // Disabled for now
+        containers.define("WAV", wav::FORMAT_WAV);
+        // containers.define("RF64", wav::FORMAT_RF64); // Disabled for now
         sampleTypes.define(wav::SAMP_TYPE_UINT8, "Uint8", wav::SAMP_TYPE_UINT8);
         sampleTypes.define(wav::SAMP_TYPE_INT16, "Int16", wav::SAMP_TYPE_INT16);
         sampleTypes.define(wav::SAMP_TYPE_INT32, "Int32", wav::SAMP_TYPE_INT32);
         sampleTypes.define(wav::SAMP_TYPE_FLOAT32, "Float32", wav::SAMP_TYPE_FLOAT32);
 
         // Load default config for option lists
-        formatId = formats.valueId(wav::FORMAT_WAV);
+        containerId = containers.valueId(wav::FORMAT_WAV);
         sampleTypeId = sampleTypes.valueId(wav::SAMP_TYPE_INT16);
 
         // Load config
@@ -60,8 +61,8 @@ public:
         if (config.conf[name].contains("recPath")) {
             folderSelect.setPath(config.conf[name]["recPath"]);
         }
-        if (config.conf[name].contains("format") && formats.keyExists(config.conf[name]["format"])) {
-            formatId = formats.keyId(config.conf[name]["format"]);
+        if (config.conf[name].contains("format") && containers.keyExists(config.conf[name]["format"])) {
+            containerId = containers.keyId(config.conf[name]["format"]);
         }
         if (config.conf[name].contains("sampleType") && sampleTypes.keyExists(config.conf[name]["sampleType"])) {
             sampleTypeId = sampleTypes.keyId(config.conf[name]["sampleType"]);
@@ -82,11 +83,12 @@ public:
         splitter.init(&volume.out);
         splitter.bindStream(&meterStream);
         meter.init(&meterStream);
+        s2m.init(NULL);
 
         // Init sinks
         basebandSink.init(NULL, complexHandler, this);
         stereoSink.init(NULL, stereoHandler, this);
-        monoSink.init(NULL, monoHandler, this);
+        monoSink.init(&s2m.out, monoHandler, this);
 
         gui::menu.registerEntry(name, menuHandler, this);
     }
@@ -142,7 +144,7 @@ public:
         else {
             samplerate = sigpath::iqFrontEnd.getSampleRate();
         }
-        writer.setFormat(formats[formatId]);
+        writer.setFormat(containers[containerId]);
         writer.setChannels((recMode == RECORDER_MODE_AUDIO && !stereo) ? 1 : 2);
         writer.setSampleType(sampleTypes[sampleTypeId]);
         writer.setSamplerate(samplerate);
@@ -159,8 +161,15 @@ public:
         if (recMode == RECORDER_MODE_AUDIO) {
             // TODO: Select the stereo to mono converter if needed
             stereoStream = sigpath::sinkManager.bindStream(selectedStreamName);
-            stereoSink.setInput(stereoStream);
-            stereoSink.start();
+            if (stereo) {
+                stereoSink.setInput(stereoStream);
+                stereoSink.start();
+            }
+            else {
+                s2m.setInput(stereoStream);
+                s2m.start();
+                monoSink.start();
+            }
         }
         else {
             // Create and bind IQ stream
@@ -179,8 +188,10 @@ public:
 
         // Close audio stream or baseband
         if (recMode == RECORDER_MODE_AUDIO) {
-            // TODO: HAS TO BE DONE PROPERLY
+            // NOTE: Has to be done before the unbind since the stream is deleted...
+            monoSink.stop();
             stereoSink.stop();
+            s2m.stop();
             sigpath::sinkManager.unbindStream(selectedStreamName, stereoStream);
         }
         else {
@@ -231,11 +242,11 @@ private:
             }
         }
 
-        ImGui::LeftLabel("WAV Format");
+        ImGui::LeftLabel("Container");
         ImGui::FillWidth();
-        if (ImGui::Combo(CONCAT("##_recorder_wav_fmt_", _this->name), &_this->formatId, _this->formats.txt)) {
+        if (ImGui::Combo(CONCAT("##_recorder_container_", _this->name), &_this->containerId, _this->containers.txt)) {
             config.acquire();
-            config.conf[_this->name]["format"] = _this->formats.key(_this->formatId);
+            config.conf[_this->name]["container"] = _this->containers.key(_this->containerId);
             config.release(true);
         }
 
@@ -431,12 +442,12 @@ private:
     bool enabled = true;
     std::string root;
 
-    OptionList<std::string, wav::Format> formats;
+    OptionList<std::string, wav::Format> containers;
     OptionList<int, wav::SampleType> sampleTypes;
     FolderSelect folderSelect;
 
     int recMode = RECORDER_MODE_AUDIO;
-    int formatId;
+    int containerId;
     int sampleTypeId;
     bool stereo = true;
     std::string selectedStreamName = "";
@@ -460,6 +471,7 @@ private:
     dsp::routing::Splitter<dsp::stereo_t> splitter;
     dsp::stream<dsp::stereo_t> meterStream;
     dsp::bench::PeakLevelMeter<dsp::stereo_t> meter;
+    dsp::convert::StereoToMono s2m;
 
     uint64_t samplerate = 48000;
 
diff --git a/misc_modules/recorder/src/riff.cpp b/misc_modules/recorder/src/riff.cpp
index 4c1fab75..c59f2760 100644
--- a/misc_modules/recorder/src/riff.cpp
+++ b/misc_modules/recorder/src/riff.cpp
@@ -2,28 +2,64 @@
 #include <stdexcept>
 
 namespace riff {
-    bool Writer::open(std::string path, char form[4]) {
-        // TODO:  Open file
+    const char* RIFF_SIGNATURE      = "RIFF";
+    const char* LIST_SIGNATURE      = "LIST";
+    const size_t RIFF_LABEL_SIZE    = 4;
 
+    bool Writer::open(std::string path, const char form[4]) {
+        std::lock_guard<std::recursive_mutex> lck(mtx);
+
+        // Open file
+        file = std::ofstream(path, std::ios::out | std::ios::binary);
+        if (!file.is_open()) { return false; }
+
+        // Begin RIFF chunk
         beginRIFF(form);
 
-        return false;
+        return true;
     }
 
     bool Writer::isOpen() {
-        
-        return false;
+        std::lock_guard<std::recursive_mutex> lck(mtx);
+        return file.is_open();
     }
 
     void Writer::close() {
+        std::lock_guard<std::recursive_mutex> lck(mtx);
+
         if (!isOpen()) { return; }
 
+        // Finalize RIFF chunk
         endRIFF();
 
+        // Close file
         file.close();
     }
 
-    void Writer::beginChunk(char id[4]) {
+    void Writer::beginList(const char id[4]) {
+        std::lock_guard<std::recursive_mutex> lck(mtx);
+
+        // Create chunk with the LIST ID and write id
+        beginChunk(LIST_SIGNATURE);
+        write((uint8_t*)id, RIFF_LABEL_SIZE);
+    }
+
+    void Writer::endList() {
+        std::lock_guard<std::recursive_mutex> lck(mtx);
+
+        if (chunks.empty()) {
+            throw std::runtime_error("No chunk to end");
+        }
+        if (memcmp(chunks.top().hdr.id, LIST_SIGNATURE, RIFF_LABEL_SIZE)) {
+            throw std::runtime_error("Top chunk not LIST chunk");
+        }
+
+        endChunk();
+    }
+
+    void Writer::beginChunk(const char id[4]) {
+        std::lock_guard<std::recursive_mutex> lck(mtx);
+
         // Create and write header
         ChunkDesc desc;
         desc.pos = file.tellp();
@@ -36,7 +72,9 @@ namespace riff {
     }
 
     void Writer::endChunk() {
-        if (!chunks.empty()) {
+        std::lock_guard<std::recursive_mutex> lck(mtx);
+
+        if (chunks.empty()) {
             throw std::runtime_error("No chunk to end");
         }
 
@@ -46,7 +84,9 @@ namespace riff {
 
         // Write size
         auto pos = file.tellp();
-        file.seekp(desc.pos + 4);
+        auto npos = desc.pos;
+        npos += 4;
+        file.seekp(npos);
         file.write((char*)&desc.hdr.size, sizeof(desc.hdr.size));
         file.seekp(pos);
 
@@ -56,31 +96,38 @@ namespace riff {
         }
     }
 
-    void Writer::write(void* data, size_t len) {
-        if (!chunks.empty()) {
+    void Writer::write(const uint8_t* data, size_t len) {
+        std::lock_guard<std::recursive_mutex> lck(mtx);
+
+        if (chunks.empty()) {
             throw std::runtime_error("No chunk to write into");
         }
         file.write((char*)data, len);
         chunks.top().hdr.size += len;
     }
 
-    void Writer::beginRIFF(char form[4]) {
+    void Writer::beginRIFF(const char form[4]) {
+        std::lock_guard<std::recursive_mutex> lck(mtx);
+
         if (!chunks.empty()) {
             throw std::runtime_error("Can't create RIFF chunk on an existing RIFF file");
         }
 
         // Create chunk with RIFF ID and write form
-        beginChunk("RIFF");
-        write(form, sizeof(form));
+        beginChunk(RIFF_SIGNATURE);
+        write((uint8_t*)form, RIFF_LABEL_SIZE);
     }
 
     void Writer::endRIFF() {
-        if (!chunks.empty()) {
+        std::lock_guard<std::recursive_mutex> lck(mtx);
+
+        if (chunks.empty()) {
             throw std::runtime_error("No chunk to end");
         }
-        if (memcmp(chunks.top().hdr.id, "RIFF", 4)) {
+        if (memcmp(chunks.top().hdr.id, RIFF_SIGNATURE, RIFF_LABEL_SIZE)) {
             throw std::runtime_error("Top chunk not RIFF chunk");
         }
+
         endChunk();
     }
 }
\ No newline at end of file
diff --git a/misc_modules/recorder/src/riff.h b/misc_modules/recorder/src/riff.h
index 6bfbaaf3..e47ccf03 100644
--- a/misc_modules/recorder/src/riff.h
+++ b/misc_modules/recorder/src/riff.h
@@ -1,4 +1,5 @@
 #pragma once
+#include <mutex>
 #include <fstream>
 #include <string>
 #include <stack>
@@ -19,22 +20,23 @@ namespace riff {
 
     class Writer {
     public:
-        bool open(std::string path, char form[4]);
+        bool open(std::string path, const char form[4]);
         bool isOpen();
         void close();
 
-        void beginList();
+        void beginList(const char id[4]);
         void endList();
 
-        void beginChunk(char id[4]);
+        void beginChunk(const char id[4]);
         void endChunk();
 
-        void write(void* data, size_t len);
+        void write(const uint8_t* data, size_t len);
 
     private:
-        void beginRIFF(char form[4]);
+        void beginRIFF(const char form[4]);
         void endRIFF();
 
+        std::recursive_mutex mtx;
         std::ofstream file;
         std::stack<ChunkDesc> chunks;
     };
diff --git a/misc_modules/recorder/src/wav.cpp b/misc_modules/recorder/src/wav.cpp
index 5a6a38a1..bd545755 100644
--- a/misc_modules/recorder/src/wav.cpp
+++ b/misc_modules/recorder/src/wav.cpp
@@ -6,7 +6,6 @@
 #include <map>
 
 namespace wav {
-    const char* RIFF_SIGNATURE          = "RIFF";
     const char* WAVE_FILE_TYPE          = "WAVE";
     const char* FORMAT_MARKER           = "fmt ";
     const char* DATA_MARKER             = "data";
@@ -30,13 +29,6 @@ namespace wav {
         _samplerate = samplerate;
         _format = format;
         _type = type;
-
-        // Initialize header with constants
-        memcpy(hdr.signature, RIFF_SIGNATURE, 4);
-        memcpy(hdr.fileType, WAVE_FILE_TYPE, 4);
-        memcpy(hdr.formatMarker, FORMAT_MARKER, 4);
-        hdr.formatHeaderLength = FORMAT_HEADER_LEN;
-        memcpy(hdr.dataMarker, DATA_MARKER, 4);
     }
 
     Writer::~Writer() { close(); }
@@ -44,14 +36,21 @@ namespace wav {
     bool Writer::open(std::string path) {
         std::lock_guard<std::recursive_mutex> lck(mtx);
         // Close previous file
-        if (_isOpen) { close(); }
+        if (rw.isOpen()) { close(); }
 
         // Reset work values
         samplesWritten = 0;
 
+        // Fill header
+        bytesPerSamp = (SAMP_BITS[_type] / 8) * _channels;
+        hdr.codec = (_type == SAMP_TYPE_FLOAT32) ? CODEC_FLOAT : CODEC_PCM;
+        hdr.channelCount = _channels;
+        hdr.sampleRate = _samplerate;
+        hdr.bitDepth = SAMP_BITS[_type];
+        hdr.bytesPerSample = bytesPerSamp;
+        hdr.bytesPerSecond = bytesPerSamp * _samplerate;
+
         // Precompute sizes and allocate buffers
-        // TODO: Get number of bits for each sample type
-        bytesPerSamp = (SAMP_BITS[_type] / 8) * _channels; // THIS IS WRONG
         switch (_type) {
         case SAMP_TYPE_UINT8:
             bufU8 = dsp::buffer::alloc<uint8_t>(STREAM_BUFFER_SIZE * _channels);
@@ -69,36 +68,37 @@ namespace wav {
             break;
         }
 
-        // Open new file
-        file.open(path, std::ios::out | std::ios::binary);
-        if (!file.is_open()) { return false; }
+        // Open file
+        if (!rw.open(path, WAVE_FILE_TYPE)) { return false; }
 
-        // Skip header, it'll be written when finalizing the file
-        uint8_t dummy[sizeof(Header)];
-        memset(dummy, 0, sizeof(dummy));
-        file.write((char*)dummy, sizeof(dummy));
+        // Write format chunk
+        rw.beginChunk(FORMAT_MARKER);
+        rw.write((uint8_t*)&hdr, sizeof(FormatHeader));
+        rw.endChunk();
 
-        _isOpen = true;
+        // Begin data chunk
+        rw.beginChunk(DATA_MARKER);
+        
         return true;
     }
 
     bool Writer::isOpen() {
         std::lock_guard<std::recursive_mutex> lck(mtx);
-        return _isOpen;
+        return rw.isOpen();
     }
 
     void Writer::close() {
         std::lock_guard<std::recursive_mutex> lck(mtx);
         // Do nothing if the file is not open
-        if (!_isOpen) { return; }
+        if (!rw.isOpen()) { return; }
 
-        // Finilize wav
-        finalize();
+        // Finish data chunk
+        rw.endChunk();
 
         // Close the file
-        file.close();
+        rw.close();
 
-        // Destroy buffers
+        // Free buffers
         if (bufU8) {
             dsp::buffer::free(bufU8);
             bufU8 = NULL;
@@ -111,15 +111,12 @@ namespace wav {
             dsp::buffer::free(bufI32);
             bufI32 = NULL;
         }
-
-        // Mark as closed
-        _isOpen = false;
     }
 
     void Writer::setChannels(int channels) {
         std::lock_guard<std::recursive_mutex> lck(mtx);
         // Do not allow settings to change while open
-        if (_isOpen) { throw std::runtime_error("Cannot change parameters while file is open"); }
+        if (rw.isOpen()) { throw std::runtime_error("Cannot change parameters while file is open"); }
 
         // Validate channel count
         if (channels < 1) { throw std::runtime_error("Channel count must be greater or equal to 1"); }
@@ -129,7 +126,7 @@ namespace wav {
     void Writer::setSamplerate(uint64_t samplerate) {
         std::lock_guard<std::recursive_mutex> lck(mtx);
         // Do not allow settings to change while open
-        if (_isOpen) { throw std::runtime_error("Cannot change parameters while file is open"); }
+        if (rw.isOpen()) { throw std::runtime_error("Cannot change parameters while file is open"); }
 
         // Validate samplerate
         if (!samplerate) { throw std::runtime_error("Samplerate must be non-zero"); }
@@ -138,42 +135,42 @@ namespace wav {
     void Writer::setFormat(Format format) {
         std::lock_guard<std::recursive_mutex> lck(mtx);
         // Do not allow settings to change while open
-        if (_isOpen) { throw std::runtime_error("Cannot change parameters while file is open"); }
+        if (rw.isOpen()) { throw std::runtime_error("Cannot change parameters while file is open"); }
         _format = format;
     }
 
     void Writer::setSampleType(SampleType type) {
         std::lock_guard<std::recursive_mutex> lck(mtx);
         // Do not allow settings to change while open
-        if (_isOpen) { throw std::runtime_error("Cannot change parameters while file is open"); }
+        if (rw.isOpen()) { throw std::runtime_error("Cannot change parameters while file is open"); }
         _type = type;
     }
 
     void Writer::write(float* samples, int count) {
         std::lock_guard<std::recursive_mutex> lck(mtx);
-        if (!_isOpen) { return; }
+        if (!rw.isOpen()) { return; }
         
         // Select different writer function depending on the chose depth
-        int tcount;
+        int tcount = count * _channels;
+        int tbytes = count * bytesPerSamp;
         switch (_type) {
         case SAMP_TYPE_UINT8:
-            tcount = count * _channels;
-            // Volk doesn't support unsigned ints :/
+            // Volk doesn't support unsigned ints yet :/
             for (int i = 0; i < tcount; i++) {
                 bufU8[i] = (samples[i] * 127.0f) + 128.0f;
             }
-            file.write((char*)bufU8, count * bytesPerSamp);
+            rw.write(bufU8, tbytes);
             break;
         case SAMP_TYPE_INT16:
-            volk_32f_s32f_convert_16i(bufI16, samples, 32767.0f, count * _channels);
-            file.write((char*)bufI16, count * bytesPerSamp);
+            volk_32f_s32f_convert_16i(bufI16, samples, 32767.0f, tcount);
+            rw.write((uint8_t*)bufI16, tbytes);
             break;
         case SAMP_TYPE_INT32:
-            volk_32f_s32f_convert_32i(bufI32, samples, 2147483647.0f, count * _channels);
-            file.write((char*)bufI32, count * bytesPerSamp);
+            volk_32f_s32f_convert_32i(bufI32, samples, 2147483647.0f, tcount);
+            rw.write((uint8_t*)bufI32, tbytes);
             break;
         case SAMP_TYPE_FLOAT32:
-            file.write((char*)samples, count * bytesPerSamp);
+            rw.write((uint8_t*)samples, tbytes);
             break;
         default:
             break;
@@ -182,17 +179,4 @@ namespace wav {
         // Increment sample counter
         samplesWritten += count;
     }
-
-    void Writer::finalize() {
-        file.seekp(file.beg);
-        hdr.codec = (_type == SAMP_TYPE_FLOAT32) ? CODEC_FLOAT : CODEC_PCM;
-        hdr.channelCount = _channels;
-        hdr.sampleRate = _samplerate;
-        hdr.bitDepth = SAMP_BITS[_type];
-        hdr.bytesPerSample = bytesPerSamp;
-        hdr.bytesPerSecond = bytesPerSamp * _samplerate;
-        hdr.dataSize = samplesWritten * bytesPerSamp;
-        hdr.fileSize = hdr.dataSize + sizeof(hdr) - 8;
-        file.write((char*)&hdr, sizeof(hdr));
-    }
 }
\ No newline at end of file
diff --git a/misc_modules/recorder/src/wav.h b/misc_modules/recorder/src/wav.h
index f18e7097..c9a95bdb 100644
--- a/misc_modules/recorder/src/wav.h
+++ b/misc_modules/recorder/src/wav.h
@@ -3,23 +3,17 @@
 #include <fstream>
 #include <stdint.h>
 #include <mutex>
+#include "riff.h"
 
 namespace wav {    
     #pragma pack(push, 1)
-    struct Header {
-        char signature[4];              // "RIFF"
-        uint32_t fileSize;              // data bytes + sizeof(WavHeader_t) - 8
-        char fileType[4];               // "WAVE"
-        char formatMarker[4];           // "fmt "
-        uint32_t formatHeaderLength;    // Always 16
-        uint16_t codec;                 // PCM (1)
+    struct FormatHeader {
+        uint16_t codec;
         uint16_t channelCount;
         uint32_t sampleRate;
         uint32_t bytesPerSecond;
         uint16_t bytesPerSample;
         uint16_t bitDepth;
-        char dataMarker[4];             // "data"
-        uint32_t dataSize;
     };
     #pragma pack(pop)
 
@@ -59,12 +53,9 @@ namespace wav {
         void write(float* samples, int count);
 
     private:
-        void finalize();
-        
         std::recursive_mutex mtx;
-        std::ofstream file;
-        Header hdr;
-        bool _isOpen = false;
+        FormatHeader hdr;
+        riff::Writer rw;
 
         int _channels;
         uint64_t _samplerate;