diff --git a/config/config_groovebox.edn b/config/config_groovebox.edn
index 59bc032a..05f22924 100644
--- a/config/config_groovebox.edn
+++ b/config/config_groovebox.edn
@@ -8,8 +8,9 @@
       (bsp/n (fixed/y     1          :view-status)
         (bsp/n (fixed/y   5          :view-sample-viewer)
           (bsp/w (fixed/x :w-sidebar :view-pool)
-            (bsp/e                   :view-samples-keys
-              (fill/y                :view-editor))))))))
+            (bsp/e                   :view-meters-input
+              (bsp/e                 :view-samples-keys
+                (fill/y              :view-editor)))))))))
 
 (keys
   (layer-if :focus-pool-import "./keys_pool_file.edn")
diff --git a/crates/app/src/view.rs b/crates/app/src/view.rs
index 9333d10a..e81cb73d 100644
--- a/crates/app/src/view.rs
+++ b/crates/app/src/view.rs
@@ -56,6 +56,9 @@ impl App {
             )))
         ))
     }
+    pub fn view_meters_input (&self) -> impl Content<TuiOut> + use<'_> {
+        self.sampler().map(|s|s.view_meters_input())
+    }
 }
 
 impl App {
diff --git a/crates/device/Cargo.toml b/crates/device/Cargo.toml
index 0f8b2230..a6529854 100644
--- a/crates/device/Cargo.toml
+++ b/crates/device/Cargo.toml
@@ -20,8 +20,9 @@ default   = [ "clock", "editor", "sequencer", "sampler", "lv2" ]
 clock     = []
 editor    = []
 meter     = []
+mixer     = []
 sequencer = [ "clock", "uuid" ]
-sampler   = [ "meter", "symphonia", "wavers" ]
+sampler   = [ "meter", "mixer", "symphonia", "wavers" ]
 lv2       = [ "livi", "winit" ]
 vst2      = []
 vst3      = []
diff --git a/crates/device/src/device.rs b/crates/device/src/device.rs
index ee6a404f..70da6c28 100644
--- a/crates/device/src/device.rs
+++ b/crates/device/src/device.rs
@@ -31,7 +31,7 @@ audio!(|self: DeviceAudio<'a>, client, scope|{
     use Device::*;
     match self.0 {
         #[cfg(feature = "sampler")]
-        Sampler(sampler) => SamplerAudio(sampler).process(client, scope),
+        Sampler(sampler) => sampler.process(client, scope),
 
         #[cfg(feature = "lv2")]
         Lv2(lv2) => lv2.process(client, scope),
diff --git a/crates/device/src/lib.rs b/crates/device/src/lib.rs
index f15f3a7a..bb773305 100644
--- a/crates/device/src/lib.rs
+++ b/crates/device/src/lib.rs
@@ -35,6 +35,9 @@ pub use self::device::*;
 #[cfg(feature = "meter")] mod meter;
 #[cfg(feature = "meter")] pub use self::meter::*;
 
+#[cfg(feature = "mixer")] mod mixer;
+#[cfg(feature = "mixer")] pub use self::mixer::*;
+
 #[cfg(feature = "lv2")] mod lv2;
 #[cfg(feature = "lv2")] pub use self::lv2::*;
 
diff --git a/crates/device/src/meter.rs b/crates/device/src/meter.rs
index 74dba443..81416bd0 100644
--- a/crates/device/src/meter.rs
+++ b/crates/device/src/meter.rs
@@ -1,16 +1,36 @@
 use crate::*;
 
-#[derive(Debug, Default, Clone)]
-pub struct RMSMeter(f32);
-
-impl RMSMeter {
-    pub fn set (&mut self, samples: &[u32]) {
-        let sum: usize = samples.iter().map(|s|*s as usize).reduce(|sum, sample|sum + sample)
-            .unwrap_or(0);
-        self.0 = (sum as f32 / samples.len() as f32).sqrt();
-    }
+#[derive(Debug, Default)]
+pub enum MeteringMode {
+    #[default]
+    Rms,
+    Log10,
 }
 
-render!(TuiOut: |self: RMSMeter, to| {
+#[derive(Debug, Default, Clone)]
+pub struct Meter(pub f32);
+
+render!(TuiOut: |self: Meter, to| {
     let [x, y, w, h] = to.area();
+    let signal = 100.0 - f32::max(0.0, f32::min(100.0, self.0.abs()));
+    let v = (signal * h as f32 / 100.0).ceil() as u16;
+    let y2 = y + h;
+    //to.blit(&format!("\r{v} {} {signal}", self.0), x * 20, y, None);
+    for y in y..(y + v) {
+        for x in x..(x + w) {
+            to.blit(&"▌", x, y2 - y, Some(Style::default().green()));
+        }
+    }
 });
+
+pub fn to_rms (samples: &[u32]) -> f32 {
+    let sum: usize = samples.iter()
+        .map(|s|*s as usize)
+        .reduce(|sum, sample|sum + sample)
+        .unwrap_or(0);
+    (sum as f32 / samples.len() as f32).sqrt()
+}
+
+pub fn to_log10 (samples: &[u32]) -> f32 {
+    0.0
+}
diff --git a/crates/device/src/mixer.rs b/crates/device/src/mixer.rs
new file mode 100644
index 00000000..d6c34432
--- /dev/null
+++ b/crates/device/src/mixer.rs
@@ -0,0 +1,41 @@
+#[derive(Debug, Default)]
+pub enum MixingMode {
+    #[default]
+    Summing,
+    Average,
+}
+
+pub fn mix_summing <const N: usize> (
+    buffer: &mut [Vec<f32>], gain: f32, frames: usize, mut next: impl FnMut()->Option<[f32;N]>,
+) -> bool {
+    let channels = buffer.len();
+    for index in 0..frames {
+        if let Some(frame) = next() {
+            for (channel, sample) in frame.iter().enumerate() {
+                let channel = channel % channels;
+                buffer[channel][index] += sample * gain;
+            }
+        } else {
+            return false
+        }
+    }
+    true
+}
+
+pub fn mix_average <const N: usize> (
+    buffer: &mut [Vec<f32>], gain: f32, frames: usize, mut next: impl FnMut()->Option<[f32;N]>,
+) -> bool {
+    let channels = buffer.len();
+    for index in 0..frames {
+        if let Some(frame) = next() {
+            for (channel, sample) in frame.iter().enumerate() {
+                let channel = channel % channels;
+                let value = buffer[channel][index];
+                buffer[channel][index] = (value + sample * gain) / 2.0;
+            }
+        } else {
+            return false
+        }
+    }
+    true
+}
diff --git a/crates/device/src/sampler/sampler_api.rs b/crates/device/src/sampler/sampler_api.rs
index e374f88e..fd120976 100644
--- a/crates/device/src/sampler/sampler_api.rs
+++ b/crates/device/src/sampler/sampler_api.rs
@@ -9,7 +9,7 @@ impl Sampler {
         //todo!();
     //}
     ///// Immutable reference to sample at cursor.
-    //fn sample_selected (&self) -> MaybeSample {
+    //fn sample_selected (&self) -> Option<Arc<RwLock<Sample>>> {
         //for (i, sample) in self.mapped.iter().enumerate() {
             //if i == self.cursor().0 {
                 //return sample.as_ref()
@@ -88,7 +88,7 @@ impl SamplerCommand {
         //Self::Select(state.set_note_pos(i))
     //}
     ///// Assign sample to pitch
-    //fn set (&self, pitch: u7, sample: MaybeSample) -> Option<Self> {
+    //fn set (&self, pitch: u7, sample: Option<Arc<RwLock<Sample>>>) -> Option<Self> {
         //let i = pitch.as_int() as usize;
         //let old = self.mapped[i].clone();
         //self.mapped[i] = sample;
@@ -106,7 +106,7 @@ impl SamplerCommand {
     //fn note_off (&self, state: &mut Sampler, pitch: u7) -> Option<Self> {
         //todo!()
     //}
-    //fn set_sample (&self, state: &mut Sampler, pitch: u7, s: MaybeSample) -> Option<Self> {
+    //fn set_sample (&self, state: &mut Sampler, pitch: u7, s: Option<Arc<RwLock<Sample>>>) -> Option<Self> {
         //Some(Self::SetSample(p, state.set_sample(p, s)))
     //}
     //fn import (&self, state: &mut Sampler, c: FileBrowserCommand) -> Option<Self> {
@@ -131,7 +131,7 @@ impl SamplerCommand {
         ////(SetGain      [p: u7, gain: f32]      cmd_todo!("\n\rtodo: {self:?}"))
         ////(NoteOn       [p: u7, velocity: u7]   cmd_todo!("\n\rtodo: {self:?}"))
         ////(NoteOff      [p: u7]                 cmd_todo!("\n\rtodo: {self:?}"))
-        ////(SetSample    [p: u7, s: MaybeSample] Some(Self::SetSample(p, state.set_sample(p, s))))
+        ////(SetSample    [p: u7, s: Option<Arc<RwLock<Sample>>>] Some(Self::SetSample(p, state.set_sample(p, s))))
         ////(Import       [c: FileBrowserCommand] match c {
             ////FileBrowserCommand::Begin => {
                 //////let voices = &state.state.voices;
@@ -154,7 +154,7 @@ impl SamplerCommand {
             ////Some(Self::RecordCancel))
         ////("record/finish" [] 
             ////Some(Self::RecordFinish))
-        ////("set/sample"    [i: u7, s: MaybeSample]
+        ////("set/sample"    [i: u7, s: Option<Arc<RwLock<Sample>>>]
             ////Some(Self::SetSample(i.expect("no index"), s.expect("no sampler"))))
         ////("set/start"     [i: u7, s: usize]
             ////Some(Self::SetStart(i.expect("no index"), s.expect("no start"))))
diff --git a/crates/device/src/sampler/sampler_audio.rs b/crates/device/src/sampler/sampler_audio.rs
index 4cea762c..cfbe7b6e 100644
--- a/crates/device/src/sampler/sampler_audio.rs
+++ b/crates/device/src/sampler/sampler_audio.rs
@@ -1,80 +1,102 @@
 use crate::*;
 
-pub struct SamplerAudio<'a>(pub &'a mut Sampler);
-
-audio!(|self: SamplerAudio<'a>, _client, scope|{
-    self.0.process_midi_in(scope);
-    self.0.clear_output_buffer();
-    self.0.process_audio_out(scope);
-    self.0.write_output_buffer(scope);
-    self.0.process_audio_in(scope);
+audio!(|self: Sampler, _client, scope|{
+    self.process_midi_in(scope);
+    self.process_audio_out(scope);
+    self.process_audio_in(scope);
     Control::Continue
 });
 
 impl Sampler {
 
     pub fn process_audio_in (&mut self, scope: &ProcessScope) {
-        let Sampler { audio_ins, input_meter, recording, .. } = self;
-        if audio_ins.len() != input_meter.len() {
-            *input_meter = vec![0.0;audio_ins.len()];
-        }
-        if let Some((_, sample)) = recording {
-            let mut sample = sample.write().unwrap();
-            if sample.channels.len() != audio_ins.len() {
-                panic!("channel count mismatch");
-            }
-            let iterator = audio_ins.iter().zip(input_meter).zip(sample.channels.iter_mut());
-            let mut length = 0;
-            for ((input, meter), channel) in iterator {
-                let slice = input.port().as_slice(scope);
-                length = length.max(slice.len());
-                let total: f32 = slice.iter().map(|x|x.abs()).sum();
-                let count = slice.len() as f32;
-                *meter = 10. * (total / count).log10();
-                channel.extend_from_slice(slice);
-            }
-            sample.end += length;
+        self.reset_input_meters();
+        if self.recording.is_some() {
+            self.record_into(scope);
         } else {
-            for (input, meter) in audio_ins.iter().zip(input_meter) {
-                let slice = input.port().as_slice(scope);
-                let total: f32 = slice.iter().map(|x|x.abs()).sum();
-                let count = slice.len() as f32;
-                *meter = 10. * (total / count).log10();
-            }
+            self.update_input_meters(scope);
         }
     }
 
-    /// Zero the output buffer.
-    pub fn clear_output_buffer (&mut self) {
-        for buffer in self.buffer.iter_mut() {
-            buffer.fill(0.0);
+    /// Make sure that input meter count corresponds to input channel count
+    fn reset_input_meters (&mut self) {
+        let channels = self.audio_ins.len();
+        if self.input_meters.len() != channels {
+            self.input_meters = vec![f32::MIN;channels];
+        }
+    }
+
+    /// Record from inputs to sample
+    fn record_into (&mut self, scope: &ProcessScope) {
+        let mut sample = self.recording
+            .as_mut().expect("no recording sample").1
+            .write().unwrap();
+        if sample.channels.len() != self.audio_ins.len() {
+            panic!("channel count mismatch");
+        }
+        let samples_with_meters = self.audio_ins.iter()
+            .zip(self.input_meters.iter_mut())
+            .zip(sample.channels.iter_mut());
+        let mut length = 0;
+        for ((input, meter), channel) in samples_with_meters {
+            let slice = input.port().as_slice(scope);
+            length = length.max(slice.len());
+            let total: f32 = slice.iter().map(|x|x.abs()).sum();
+            let count = slice.len() as f32;
+            *meter = 10. * (total / count).log10();
+            channel.extend_from_slice(slice);
+        }
+        sample.end += length;
+    }
+
+    /// Update input meters
+    fn update_input_meters (&mut self, scope: &ProcessScope) {
+        for (input, meter) in self.audio_ins.iter().zip(self.input_meters.iter_mut()) {
+            let slice = input.port().as_slice(scope);
+            let total: f32 = slice.iter().map(|x|x.abs()).sum();
+            let count = slice.len() as f32;
+            *meter = 10. * (total / count).log10();
+        }
+    }
+
+    /// Make sure that output meter count corresponds to input channel count
+    fn reset_output_meters (&mut self) {
+        let channels = self.audio_outs.len();
+        if self.output_meters.len() != channels {
+            self.output_meters = vec![f32::MIN;channels];
         }
     }
 
     /// Mix all currently playing samples into the output.
     pub fn process_audio_out (&mut self, scope: &ProcessScope) {
-        let Sampler { ref mut buffer, voices, output_gain, .. } = self;
+        self.clear_output_buffer();
+        self.populate_output_buffer(scope.n_frames() as usize);
+        self.write_output_buffer(scope);
+    }
+
+    /// Zero the output buffer.
+    fn clear_output_buffer (&mut self) {
+        for buffer in self.buffer.iter_mut() {
+            buffer.fill(0.0);
+        }
+    }
+
+    /// Write playing voices to output buffer
+    fn populate_output_buffer (&mut self, frames: usize) {
+        let Sampler { ref mut buffer, voices, output_gain, mixing_mode, .. } = self;
         let channel_count = buffer.len();
-        voices.write().unwrap().retain_mut(|voice|{
-            for index in 0..scope.n_frames() as usize {
-                if let Some(frame) = voice.next() {
-                    for (channel, sample) in frame.iter().enumerate() {
-                        // Averaging mixer:
-                        //self.buffer[channel % channel_count][index] = (
-                            //(self.buffer[channel % channel_count][index] + sample * self.output_gain) / 2.0
-                        //);
-                        buffer[channel % channel_count][index] += sample * *output_gain;
-                    }
-                } else {
-                    return false
-                }
-            }
-            true
-        });
+        match mixing_mode {
+            MixingMode::Summing => voices.write().unwrap().retain_mut(|voice|{
+                mix_summing(buffer.as_mut_slice(), *output_gain, frames, ||voice.next())
+            }),
+            MixingMode::Average => voices.write().unwrap().retain_mut(|voice|{
+                mix_average(buffer.as_mut_slice(), *output_gain, frames, ||voice.next())
+            }),
+        }
     }
 
     /// Write output buffer to output ports.
-    pub fn write_output_buffer (&mut self, scope: &ProcessScope) {
+    fn write_output_buffer (&mut self, scope: &ProcessScope) {
         let Sampler { ref mut audio_outs, buffer, .. } = self;
         for (i, port) in audio_outs.iter_mut().enumerate() {
             let buffer = &buffer[i];
diff --git a/crates/device/src/sampler/sampler_data.rs b/crates/device/src/sampler/sampler_data.rs
index 8c3b3bda..b4834174 100644
--- a/crates/device/src/sampler/sampler_data.rs
+++ b/crates/device/src/sampler/sampler_data.rs
@@ -1,6 +1,7 @@
 use crate::*;
 
 impl Sample {
+
     /// Read WAV from file
     pub fn read_data (src: &str) -> Usually<(usize, Vec<Vec<f32>>)> {
         let mut channels: Vec<wavers::Samples<f32>> = vec![];
@@ -16,6 +17,7 @@ impl Sample {
         }
         Ok((end, data))
     }
+
     pub fn from_file (path: &PathBuf) -> Usually<Self> {
         let name = path.file_name().unwrap().to_string_lossy().into();
         let mut sample = Self { name, ..Default::default() };
@@ -49,6 +51,7 @@ impl Sample {
         sample.end = sample.channels.iter().fold(0, |l, c|l + c.len());
         Ok(sample)
     }
+
     fn decode_packet (
         &mut self, decoder: &mut Box<dyn Decoder>, packet: Packet
     ) -> Usually<()> {
@@ -84,4 +87,5 @@ impl Sample {
         }
         Ok(())
     }
+
 }
diff --git a/crates/device/src/sampler/sampler_model.rs b/crates/device/src/sampler/sampler_model.rs
index 2a55e143..ad429a9d 100644
--- a/crates/device/src/sampler/sampler_model.rs
+++ b/crates/device/src/sampler/sampler_model.rs
@@ -1,55 +1,76 @@
 use crate::*;
 
-pub type MaybeSample = Option<Arc<RwLock<Sample>>>;
-
 /// The sampler device plays sounds in response to MIDI notes.
 #[derive(Debug)]
 pub struct Sampler {
-    pub name:        String,
-    pub mapped:      [MaybeSample;128],
-    pub recording:   Option<(usize, Arc<RwLock<Sample>>)>,
-    pub unmapped:    Vec<Arc<RwLock<Sample>>>,
-    pub voices:      Arc<RwLock<Vec<Voice>>>,
-    pub midi_in:     Option<JackMidiIn>,
-    pub audio_ins:   Vec<JackAudioIn>,
-    pub input_meter: Vec<f32>,
-    pub audio_outs:  Vec<JackAudioOut>,
-    pub buffer:      Vec<Vec<f32>>,
-    pub output_gain: f32,
-    pub editing: MaybeSample,
-    pub mode:    Option<SamplerMode>,
-    /// Size of actual notes area
-    pub size:    Measure<TuiOut>,
-    /// Lowest note displayed
-    pub note_lo: AtomicUsize,
-    /// Selected note
-    pub note_pt: AtomicUsize,
-    /// Selected note as row/col
-    pub cursor:  (AtomicUsize, AtomicUsize),
-    pub color:   ItemTheme
+    /// Name of sampler.
+    pub name:          String,
+    /// Device color.
+    pub color:         ItemTheme,
+    /// Audio input ports. Samples get recorded here.
+    pub audio_ins:     Vec<JackAudioIn>,
+    /// Audio input meters.
+    pub input_meters:  Vec<f32>,
+    /// Sample currently being recorded.
+    pub recording:     Option<(usize, Arc<RwLock<Sample>>)>,
+    /// Recording buffer.
+    pub buffer:        Vec<Vec<f32>>,
+    /// Samples mapped to MIDI notes.
+    pub mapped:        [Option<Arc<RwLock<Sample>>>;128],
+    /// Samples that are not mapped to MIDI notes.
+    pub unmapped:      Vec<Arc<RwLock<Sample>>>,
+    /// Sample currently being edited.
+    pub editing:       Option<Arc<RwLock<Sample>>>,
+    /// MIDI input port. Triggers sample playback.
+    pub midi_in:       Option<JackMidiIn>,
+    /// Collection of currently playing instances of samples.
+    pub voices:        Arc<RwLock<Vec<Voice>>>,
+    /// Audio output ports. Voices get played here.
+    pub audio_outs:    Vec<JackAudioOut>,
+    /// Audio output meters.
+    pub output_meters: Vec<f32>,
+    /// How to mix the voices.
+    pub mixing_mode:   MixingMode,
+    /// How to meter the inputs and outputs.
+    pub metering_mode: MeteringMode,
+    /// Fixed gain applied to all output.
+    pub output_gain:   f32,
+    /// Currently active modal, if any.
+    pub mode:          Option<SamplerMode>,
+    /// Size of rendered sampler.
+    pub size:          Measure<TuiOut>,
+    /// Lowest note displayed.
+    pub note_lo:       AtomicUsize,
+    /// Currently selected note.
+    pub note_pt:       AtomicUsize,
+    /// Selected note as row/col.
+    pub cursor:        (AtomicUsize, AtomicUsize),
 }
 
 impl Default for Sampler {
     fn default () -> Self {
         Self {
-            midi_in:     None,
-            audio_ins:   vec![],
-            input_meter: vec![0.0;2],
-            audio_outs:  vec![],
-            name:        "tek_sampler".to_string(),
-            mapped:      [const { None };128],
-            unmapped:    vec![],
-            voices:      Arc::new(RwLock::new(vec![])),
-            buffer:      vec![vec![0.0;16384];2],
-            output_gain: 1.,
-            recording:   None,
-            mode:        None,
-            editing:     None,
-            size:        Default::default(),
-            note_lo:     0.into(),
-            note_pt:     0.into(),
-            cursor:      (0.into(), 0.into()),
-            color:       Default::default(),
+            midi_in:        None,
+            audio_ins:      vec![],
+            input_meters:   vec![0.0;2],
+            output_meters:  vec![0.0;2],
+            audio_outs:     vec![],
+            name:           "tek_sampler".to_string(),
+            mapped:         [const { None };128],
+            unmapped:       vec![],
+            voices:         Arc::new(RwLock::new(vec![])),
+            buffer:         vec![vec![0.0;16384];2],
+            output_gain:    1.,
+            recording:      None,
+            mode:           None,
+            editing:        None,
+            size:           Default::default(),
+            note_lo:        0.into(),
+            note_pt:        0.into(),
+            cursor:         (0.into(), 0.into()),
+            color:          Default::default(),
+            mixing_mode:    Default::default(),
+            metering_mode:  Default::default(),
         }
     }
 }
diff --git a/crates/device/src/sampler/sampler_view.rs b/crates/device/src/sampler/sampler_view.rs
index d984b3a4..8ceef605 100644
--- a/crates/device/src/sampler/sampler_view.rs
+++ b/crates/device/src/sampler/sampler_view.rs
@@ -102,6 +102,12 @@ impl Sampler {
     pub fn status (&self, index: usize) -> impl Content<TuiOut> {
         draw_status(self.mapped[index].as_ref())
     }
+
+    pub fn view_meters_input (&self) -> impl Content<TuiOut> + use<'_> {
+        Tui::bg(Black, Fixed::x(2, Map::east(1, ||self.input_meters.iter(), |value, _index|{
+            Fill::y(Meter(*value))
+        })))
+    }
 }
 
 fn draw_list_item (sample: &Option<Arc<RwLock<Sample>>>) -> String {