diff --git a/app/src/main/java/com/github/axet/audiorecorder/activities/MainActivity.java b/app/src/main/java/com/github/axet/audiorecorder/activities/MainActivity.java
index c555f02..b85f0b5 100644
--- a/app/src/main/java/com/github/axet/audiorecorder/activities/MainActivity.java
+++ b/app/src/main/java/com/github/axet/audiorecorder/activities/MainActivity.java
@@ -40,6 +40,7 @@ import com.github.axet.androidlibrary.widgets.ErrorDialog;
 import com.github.axet.androidlibrary.widgets.OpenFileDialog;
 import com.github.axet.androidlibrary.widgets.SearchView;
 import com.github.axet.audiolibrary.app.RawSamples;
+import com.github.axet.audiolibrary.app.Sound;
 import com.github.axet.audiolibrary.encoders.FormatWAV;
 import com.github.axet.audiorecorder.R;
 import com.github.axet.audiorecorder.app.AudioApplication;
@@ -663,7 +664,7 @@ public class MainActivity extends AppCompatThemeActivity {
     void updateHeader() {
         Uri uri = storage.getStoragePath();
         long free = Storage.getFree(this, uri);
-        long sec = Storage.average(this, free);
+        long sec = Storage.average(this, Sound.getAudioFormat(this), free);
         TextView text = (TextView) findViewById(R.id.space_left);
         text.setText(AudioApplication.formatFree(this, free, sec));
     }
diff --git a/app/src/main/java/com/github/axet/audiorecorder/activities/RecordingActivity.java b/app/src/main/java/com/github/axet/audiorecorder/activities/RecordingActivity.java
index 36fc274..2e406a0 100644
--- a/app/src/main/java/com/github/axet/audiorecorder/activities/RecordingActivity.java
+++ b/app/src/main/java/com/github/axet/audiorecorder/activities/RecordingActivity.java
@@ -519,7 +519,7 @@ public class RecordingActivity extends AppCompatThemeActivity {
                     editor.commit();
                 }
                 Log.d(TAG, "create recording at: " + targetUri);
-                app.recording = new RecordingStorage(this, pitch.getPitchTime(), targetUri);
+                app.recording = new RecordingStorage(this, Sound.getAudioFormat(this), pitch.getPitchTime(), targetUri);
             }
             recording = app.recording;
             synchronized (recording.handlers) {
@@ -754,7 +754,7 @@ public class RecordingActivity extends AppCompatThemeActivity {
         String ext = shared.getString(AudioApplication.PREFERENCE_ENCODING, "");
 
         if (shared.getBoolean(AudioApplication.PREFERENCE_FLY, false)) {
-            perSec = Factory.getEncoderRate(ext, recording.sampleRate);
+            perSec = Factory.getEncoderRate(Sound.getAudioFormat(this), ext, recording.sampleRate);
             try {
                 free = Storage.getFree(this, recording.targetUri);
             } catch (RuntimeException e) { // IllegalArgumentException
diff --git a/app/src/main/java/com/github/axet/audiorecorder/activities/SettingsActivity.java b/app/src/main/java/com/github/axet/audiorecorder/activities/SettingsActivity.java
index f3a0944..650d9f6 100644
--- a/app/src/main/java/com/github/axet/audiorecorder/activities/SettingsActivity.java
+++ b/app/src/main/java/com/github/axet/audiorecorder/activities/SettingsActivity.java
@@ -99,7 +99,7 @@ public class SettingsActivity extends AppCompatSettingsThemeActivity implements
             storage.migrateLocalStorageDialog(this);
         if (key.equals(AudioApplication.PREFERENCE_RATE)) {
             int sampleRate = Integer.parseInt(sharedPreferences.getString(AudioApplication.PREFERENCE_RATE, ""));
-            if (sampleRate != Sound.getValidRecordRate(Sound.getInMode(this), sampleRate))
+            if (sampleRate != Sound.getValidRecordRate(Sound.getAudioFormat(this), Sound.getInMode(this), sampleRate))
                 Toast.Text(this, "Not supported Hz");
         }
     }
@@ -163,6 +163,7 @@ public class SettingsActivity extends AppCompatSettingsThemeActivity implements
             bindPreferenceSummaryToValue(pm.findPreference(AudioApplication.PREFERENCE_CHANNELS));
             bindPreferenceSummaryToValue(pm.findPreference(AudioApplication.PREFERENCE_FORMAT));
             bindPreferenceSummaryToValue(pm.findPreference(AudioApplication.PREFERENCE_VOLUME));
+            bindPreferenceSummaryToValue(pm.findPreference(AudioApplication.PREFERENCE_AUDIOFORMAT));
 
             StoragePathPreferenceCompat s = (StoragePathPreferenceCompat) pm.findPreference(AudioApplication.PREFERENCE_STORAGE);
             s.setStorage(new Storage(getContext()));
diff --git a/app/src/main/java/com/github/axet/audiorecorder/app/RecordingStorage.java b/app/src/main/java/com/github/axet/audiorecorder/app/RecordingStorage.java
index d918099..fd6e6ef 100644
--- a/app/src/main/java/com/github/axet/audiorecorder/app/RecordingStorage.java
+++ b/app/src/main/java/com/github/axet/audiorecorder/app/RecordingStorage.java
@@ -66,7 +66,7 @@ public class RecordingStorage {
 
     public int pitchTime; // screen width
 
-    public RecordingStorage(Context context, int pitchTime, Uri targetUri) {
+    public RecordingStorage(Context context, int format, int pitchTime, Uri targetUri) {
         this.context = context;
         this.pitchTime = pitchTime;
         this.targetUri = targetUri;
@@ -75,7 +75,7 @@ public class RecordingStorage {
         sampleRate = Sound.getSampleRate(context);
         samplesUpdate = (int) (pitchTime * sampleRate / 1000f);
         samplesUpdateStereo = samplesUpdate * Sound.getChannels(context);
-        info = new RawSamples.Info(sampleRate, Sound.getChannels(context));
+        info = new RawSamples.Info(format, sampleRate, Sound.getChannels(context));
     }
 
     public void startRecording(int source) {
diff --git a/app/src/main/java/com/github/axet/audiorecorder/services/ControlsService.java b/app/src/main/java/com/github/axet/audiorecorder/services/ControlsService.java
index 2880a81..f7efdd7 100644
--- a/app/src/main/java/com/github/axet/audiorecorder/services/ControlsService.java
+++ b/app/src/main/java/com/github/axet/audiorecorder/services/ControlsService.java
@@ -27,6 +27,7 @@ import com.github.axet.androidlibrary.services.PersistentService;
 import com.github.axet.androidlibrary.widgets.NotificationChannelCompat;
 import com.github.axet.androidlibrary.widgets.RemoteNotificationCompat;
 import com.github.axet.androidlibrary.widgets.RemoteViewsCompat;
+import com.github.axet.audiolibrary.app.Sound;
 import com.github.axet.audiolibrary.app.Storage;
 import com.github.axet.audiorecorder.R;
 import com.github.axet.audiorecorder.activities.MainActivity;
@@ -128,7 +129,7 @@ public class ControlsService extends PersistentService {
                         title = getString(R.string.app_name);
                         Uri f = storage.getStoragePath();
                         long free = Storage.getFree(context, f);
-                        long sec = Storage.average(context, free);
+                        long sec = Storage.average(context, Sound.getAudioFormat(context), free);
                         text = AudioApplication.formatFree(context, free, sec);
                         builder = new RemoteNotificationCompat.Low(context, R.layout.notifictaion);
                         builder.setViewVisibility(R.id.notification_record, View.VISIBLE);
diff --git a/app/src/main/java/com/github/axet/audiorecorder/widgets/RecordingSourcePreferenceCompat.java b/app/src/main/java/com/github/axet/audiorecorder/widgets/RecordingSourcePreferenceCompat.java
index 1a8388f..60c571c 100644
--- a/app/src/main/java/com/github/axet/audiorecorder/widgets/RecordingSourcePreferenceCompat.java
+++ b/app/src/main/java/com/github/axet/audiorecorder/widgets/RecordingSourcePreferenceCompat.java
@@ -6,6 +6,8 @@ import android.content.res.TypedArray;
 import android.os.Build;
 import android.preference.PreferenceManager;
 import android.support.v7.preference.ListPreference;
+import android.support.v7.preference.ListPreferenceDialogFragmentCompat;
+import android.support.v7.preference.PreferenceViewHolder;
 import android.util.AttributeSet;
 
 import com.github.axet.audiolibrary.app.Sound;
diff --git a/app/src/main/res/values/attrs.xml b/app/src/main/res/values/attrs.xml
index 18e8db7..570c35f 100644
--- a/app/src/main/res/values/attrs.xml
+++ b/app/src/main/res/values/attrs.xml
@@ -26,6 +26,16 @@
         <item>@string/source_internal</item>
     </string-array>
 
+    <string-array name="audioformat_text">
+        <item>16-bit PCM</item>
+        <item>24-bit PCM (float)</item>
+    </string-array>
+
+    <string-array name="audioformat_values" translatable="false">
+        <item>16</item>
+        <item>float</item>
+    </string-array>
+
     <string-array name="themes_values" translatable="false">
         <item>@string/Theme_Light</item>
         <item>@string/Theme_Dark</item>
diff --git a/app/src/main/res/xml/pref_general.xml b/app/src/main/res/xml/pref_general.xml
index 2605104..f620ee5 100644
--- a/app/src/main/res/xml/pref_general.xml
+++ b/app/src/main/res/xml/pref_general.xml
@@ -7,6 +7,16 @@
             android:summary="/sdcard/some/"
             android:title="@string/pref_storage_title" />
 
+        <ListPreference
+            android:defaultValue="16"
+            android:entries="@array/audioformat_text"
+            android:entryValues="@array/audioformat_values"
+            android:key="audioformat"
+            android:negativeButtonText="@null"
+            android:positiveButtonText="@null"
+            android:summary=""
+            android:title="Audio Format" />
+
         <com.github.axet.audiorecorder.widgets.RecordingSourcePreferenceCompat
             android:defaultValue="mic"
             android:entries="@array/source_text"