diff --git a/src/audio_transmitter/mod.rs b/src/audio_transmitter/mod.rs
index 3ac1af1..5b5aa9a 100644
--- a/src/audio_transmitter/mod.rs
+++ b/src/audio_transmitter/mod.rs
@@ -51,13 +51,13 @@ pub fn audio_transmitter_main(
 
     // TODO: from cli
     let mut carrier = TwoStateCarrier::new(
-        3200,                                  // freq_low
-        3840,                                  // freq_high
+        320,                                  // freq_low
+        340,                                  // freq_high
         cpal_output_config.sample_rate().0, // sample_rate
-        48,                                    // symbol_rate
+        20,                                    // symbol_rate
     );
 
-    let mut leftovers: Vec<f64> = vec![];
+    let mut leftovers: VecDeque<f64> = vec![].into();
 
     // TODO: config .clone()s should be obsolete
     let output_stream = match cpal_output_config.sample_format() {
@@ -178,60 +178,51 @@ fn give_output_pcm<T>(
     pcm: &mut [T],
     rx_for_mod: &mut Receiver<u8>,
     carrier: &mut TwoStateCarrier,
-    leftovers: &mut Vec<f64>,
+    leftovers: &mut VecDeque<f64>,
 ) where
     T: Sample + std::fmt::Debug + FromSample<f64>,
 {
     trace!("ALSA demands {} samples...", pcm.len());
     let mut output = pcm.iter_mut().peekable();
-    let mut leftovers_owned = leftovers.clone();
-    let mut leftovers_iter = leftovers_owned.into_iter();
 
-    while let Some(samp) = leftovers_iter.next() {
+    while let Some(samp) = leftovers.pop_front() {
         if let Some(sample_to_write) = output.next() { 
             *sample_to_write = samp.to_sample::<T>();
         } else {
-            *leftovers = leftovers_iter.collect();
-            //leftovers.extend(leftovers_iter);
-            trace!("ALSA demand fulfilled (last samp with leftovers)! collected {} leftovers", leftovers.len());
+            trace!("ALSA demand fulfilled (last samp with leftovers), {} leftovers remain", leftovers.len());
             return; 
         }
     }
 
     while let Ok(byte) = rx_for_mod.try_recv() {
-        //trace!("recv byte {}", byte);
         let samps = carrier.byte_into_fsk_samples(&byte);
-        let mut samps_iter = samps.iter();
-        //trace!("Samples for this byte: {:?}", samps_iter);
+        trace!("new ether samps {:?}", samps);
+        let mut samps_iter = samps.iter().cloned();
         while let Some(samp) = samps_iter.next() {
             if let Some(sample_to_write) = output.next() {
                 *sample_to_write = samp.to_sample::<T>();
             } else {
-                *leftovers = leftovers_iter.collect();
-                //leftovers.extend(samps_iter);
-                trace!("{:?}", leftovers);
+                let mut collected = samps_iter.collect::<VecDeque<f64>>();
+                leftovers.append(&mut collected);
                 trace!("ALSA demand fulfilled (last samp with modulated eth data)! collected {} leftovers", leftovers.len());
                 return;
             }
         }
     }
-    //trace!("No more eth frame bytes, idling carrier");
     while let Some(_) = output.peek() {
         let idle_samps = carrier.idle();
-        let mut idle_samps_iter = idle_samps.iter();
+        let mut idle_samps_iter = idle_samps.iter().cloned();
         while let Some(samp) = idle_samps_iter.next() {
             if let Some(sample_to_write) = output.next() {
                 *sample_to_write = samp.to_sample::<T>();
             } else {
-                *leftovers = leftovers_iter.collect();
-                //leftovers.extend(idle_samps_iter);
+                let mut collected = idle_samps_iter.collect::<VecDeque<f64>>();
+                leftovers.append(&mut collected);
                 trace!("ALSA demand fulfilled (last samp with empty carrier)! collected {} leftovers", leftovers.len());
                 return; 
             }
         }
     }
 
-    //*leftovers = leftovers_iter.collect();
-    leftovers.extend(leftovers_iter);
-    trace!("ALSA demand fulfilled! collected {} leftovers", leftovers.len());
+    trace!("Alsa demand fulfilled with no leftovers, apparently. (leftovers={})", leftovers.len());
 }