diff --git a/cmd/sdrd/dsp_loop.go b/cmd/sdrd/dsp_loop.go
index a579752..f8149a8 100644
--- a/cmd/sdrd/dsp_loop.go
+++ b/cmd/sdrd/dsp_loop.go
@@ -32,6 +32,7 @@ func runDSP(ctx context.Context, srcMgr *sourceManager, cfg config.Config, det *
 	enc := json.NewEncoder(eventFile)
 	dcBlocker := dsp.NewDCBlocker(0.995)
 	state := &phaseState{}
+	var frameID uint64
 	for {
 		select {
 		case <-ctx.Done():
@@ -44,6 +45,7 @@ func runDSP(ctx context.Context, srcMgr *sourceManager, cfg config.Config, det *
 			dcBlocker.Reset()
 			ticker.Reset(rt.cfg.FrameInterval())
 		case <-ticker.C:
+			frameID++
 			art, err := rt.captureSpectrum(srcMgr, rec, dcBlocker, gpuState)
 			if err != nil {
 				log.Printf("read IQ: %v", err)
@@ -58,6 +60,7 @@ func runDSP(ctx context.Context, srcMgr *sourceManager, cfg config.Config, det *
 				log.Printf("received IQ samples")
 				rt.gotSamples = true
 			}
+			logging.Debug("trace", "capture_done", "trace", frameID, "allIQ", len(art.allIQ), "detailIQ", len(art.detailIQ))
 			state.surveillance = rt.buildSurveillanceResult(art)
 			state.refinement = rt.runRefinement(art, state.surveillance, extractMgr, rec)
 			finished := state.surveillance.Finished
@@ -77,6 +80,23 @@ func runDSP(ctx context.Context, srcMgr *sourceManager, cfg config.Config, det *
 					}
 					aqCfg := extractionConfig{firTaps: rt.cfg.Recorder.ExtractionTaps, bwMult: rt.cfg.Recorder.ExtractionBwMult}
 					streamSnips, streamRates := extractForStreaming(extractMgr, art.allIQ, rt.cfg.SampleRate, rt.cfg.CenterHz, streamSignals, rt.streamPhaseState, rt.streamOverlap, aqCfg)
+					nonEmpty := 0
+					minLen := 0
+					maxLen := 0
+					for i := range streamSnips {
+						l := len(streamSnips[i])
+						if l == 0 {
+							continue
+						}
+						nonEmpty++
+						if minLen == 0 || l < minLen {
+							minLen = l
+						}
+						if l > maxLen {
+							maxLen = l
+						}
+					}
+					logging.Debug("trace", "extract_stats", "trace", frameID, "signals", len(streamSignals), "nonempty", nonEmpty, "minLen", minLen, "maxLen", maxLen)
 					items := make([]recorder.StreamFeedItem, 0, len(streamSignals))
 					for j, ds := range streamSignals {
 						className := "<nil>"
@@ -107,9 +127,10 @@ func runDSP(ctx context.Context, srcMgr *sourceManager, cfg config.Config, det *
 						log.Printf("LIVEAUDIO DSP: feedItems=%d", len(items))
 					}
 					if len(items) > 0 {
-						rec.FeedSnippets(items)
+						rec.FeedSnippets(items, frameID)
+						logging.Debug("trace", "feed", "trace", frameID, "items", len(items), "signals", len(streamSignals), "allIQ", len(art.allIQ))
 					} else {
-						logging.Warn("gap", "feed_empty", "signals", len(streamSignals))
+						logging.Warn("gap", "feed_empty", "signals", len(streamSignals), "trace", frameID)
 					}
 				}
 				rt.maintenance(displaySignals, rec)
diff --git a/internal/recorder/recorder.go b/internal/recorder/recorder.go
index d8a796f..7e473a9 100644
--- a/internal/recorder/recorder.go
+++ b/internal/recorder/recorder.go
@@ -310,7 +310,7 @@ func (m *Manager) SliceRecent(seconds float64) ([]complex64, int, float64) {
 // FeedSnippets is called once per DSP frame with pre-extracted IQ snippets
 // (GPU-accelerated FreqShift+FIR+Decimate). The Streamer handles demod with
 // persistent state (overlap-save, stereo decode, de-emphasis) asynchronously.
-func (m *Manager) FeedSnippets(items []StreamFeedItem) {
+func (m *Manager) FeedSnippets(items []StreamFeedItem, traceID uint64) {
 	if m == nil || m.streamer == nil || len(items) == 0 {
 		return
 	}
@@ -339,7 +339,7 @@ func (m *Manager) FeedSnippets(items []StreamFeedItem) {
 			snipRate: item.SnipRate,
 		}
 	}
-	m.streamer.FeedSnippets(internal)
+	m.streamer.FeedSnippets(internal, traceID)
 }
 
 // StreamFeedItem is the public type for passing extracted snippets from DSP loop.
diff --git a/internal/recorder/streamer.go b/internal/recorder/streamer.go
index afb965f..b26cea7 100644
--- a/internal/recorder/streamer.go
+++ b/internal/recorder/streamer.go
@@ -155,7 +155,8 @@ type streamFeedItem struct {
 }
 
 type streamFeedMsg struct {
-	items []streamFeedItem
+	traceID uint64
+	items   []streamFeedItem
 }
 
 type Streamer struct {
@@ -257,7 +258,7 @@ func (st *Streamer) hasListenersLocked() bool {
 //
 // IMPORTANT: The caller (Manager.FeedSnippets) already copies the snippet
 // data, so items can be passed directly without another copy.
-func (st *Streamer) FeedSnippets(items []streamFeedItem) {
+func (st *Streamer) FeedSnippets(items []streamFeedItem, traceID uint64) {
 	st.mu.Lock()
 	recEnabled := st.policy.Enabled && (st.policy.RecordAudio || st.policy.RecordIQ)
 	hasListeners := st.hasListenersLocked()
@@ -281,7 +282,7 @@ func (st *Streamer) FeedSnippets(items []streamFeedItem) {
 	}
 
 	select {
-	case st.feedCh <- streamFeedMsg{items: items}:
+	case st.feedCh <- streamFeedMsg{traceID: traceID, items: items}:
 	default:
 		st.droppedFeed++
 		logging.Warn("drop", "feed_drop", "count", st.droppedFeed)
@@ -297,12 +298,14 @@ func (st *Streamer) processFeed(msg streamFeedMsg) {
 	if !st.lastProcTS.IsZero() {
 		gap := now.Sub(st.lastProcTS)
 		if gap > 150*time.Millisecond {
-			logging.Warn("gap", "process_gap", "gap_ms", gap.Milliseconds())
+			logging.Warn("gap", "process_gap", "gap_ms", gap.Milliseconds(), "trace", msg.traceID)
 		}
 	}
 	st.lastProcTS = now
 	defer st.mu.Unlock()
 
+	logging.Debug("trace", "process_feed", "trace", msg.traceID, "items", len(msg.items))
+
 	if !recEnabled && !hasListeners {
 		return
 	}
@@ -390,7 +393,12 @@ func (st *Streamer) processFeed(msg streamFeedMsg) {
 		}
 
 		// Demod with persistent state
+		logging.Debug("trace", "demod_start", "trace", msg.traceID, "signal", sess.signalID, "snip_len", len(item.snippet), "snip_rate", item.snipRate)
 		audio, audioRate := sess.processSnippet(item.snippet, item.snipRate)
+		logging.Debug("trace", "demod_done", "trace", msg.traceID, "signal", sess.signalID, "audio_len", len(audio), "audio_rate", audioRate)
+		if len(audio) == 0 {
+			logging.Warn("gap", "audio_empty", "signal", sess.signalID, "snip_len", len(item.snippet), "snip_rate", item.snipRate)
+		}
 		if len(audio) > 0 {
 			if sess.wavSamples == 0 && audioRate > 0 {
 				sess.sampleRate = audioRate