diff --git a/app/build.gradle b/app/build.gradle
index 2e5dbe5..7c9c45c 100644
--- a/app/build.gradle
+++ b/app/build.gradle
@@ -12,8 +12,8 @@ android {
         applicationId "at.lockstep"
         minSdk 24
         targetSdk 34
-        versionCode 10003
-        versionName "1.0.3"
+        versionCode 10004
+        versionName "1.0.4"
 
         testInstrumentationRunner "androidx.test.runner.AndroidJUnitRunner"
         vectorDrawables {
diff --git a/app/src/main/cpp/CMakeLists.txt b/app/src/main/cpp/CMakeLists.txt
index 62815a2..cd93dfd 100644
--- a/app/src/main/cpp/CMakeLists.txt
+++ b/app/src/main/cpp/CMakeLists.txt
@@ -35,7 +35,6 @@ add_library(${CMAKE_PROJECT_NAME} SHARED
     jni_mpg123.cpp
     jni_lockstep.cpp
     jni_stepdetector.cpp
-    StepDetector.cpp
 )
 
 find_package (oboe REQUIRED CONFIG)
diff --git a/app/src/main/cpp/StepDetector.cpp b/app/src/main/cpp/StepDetector.cpp
deleted file mode 100644
index aebfe41..0000000
--- a/app/src/main/cpp/StepDetector.cpp
+++ /dev/null
@@ -1,49 +0,0 @@
-//
-// Created by david on 03.03.2026.
-//
-
-#include "StepDetector.h"
-
-// TODO: repeated code in libpasada. We could use the StepDetector class from there in jni_stepdetector.cpp
-
-// TODO: we are hardcoding filter coefficients for 60 Hz
-// TODO: this is tolerable for 50 Hz
-
-// TODO: check if we can do with floats instead of doubles
-// (check how much the [already bad] accuracy of filtering suffers)
-
-// TODO: in Java, check if delta timestamps effectively match FPS
-// TODO: FPS constant should be passed as argument to C++ (but we keep an FPS define to validate the coefficients)
-
-// Butterworth filter: order=5, fc=0.5, fs=60, btype='highpass'
-static std::vector hpf_taps_b {0.91875845, -4.59379227,  9.18758454, -9.18758454,  4.59379227, -0.91875845};
-static std::vector hpf_taps_a {1.        , -4.83056552,  9.33652742, -9.02545247,  4.36360803, -0.8441171};
-static size_t upslope_width = 4;
-const size_t len_refr = (size_t) (FPS / (MAX_BPM / 60));
-
-StepDetector::StepDetector(StepListener *listener) :
-    listener(listener),
-    f_highpass(hpf_taps_b, hpf_taps_a),
-    f_neg(1, 0, 0, std::vector {-1.0}),
-    f_ssf(upslope_width),
-    f_ssd(len_refr),
-    f_sqi(upslope_width)
-{}
-
-#if (FPS != 60)
-#error "FPS must currently be 60, as highpass taps are pre-computed for that value"
-#endif
-
-void StepDetector::filter(std::vector<float> values) {
-    // TODO: later on, we should use a vector projection towards gravity
-    auto s0 = (double) values[1]; // take y-axis value for now
-    auto s1 = f_highpass.filter(s0);
-    auto s2 = f_neg.filter(s1);
-    auto s3 = f_ssf.filter(s2);
-    auto s4 = f_ssd.filter(s3);
-    auto q5 = f_sqi.filter(s2, s3, s4);
-    // is step, step quality is OK, and we have a listener?
-    if(s4 > 0.0 && q5 > 0.0 && listener != nullptr) {
-        listener->playBeat();
-    }
-}
diff --git a/app/src/main/cpp/StepDetector.h b/app/src/main/cpp/StepDetector.h
deleted file mode 100644
index 66145dd..0000000
--- a/app/src/main/cpp/StepDetector.h
+++ /dev/null
@@ -1,27 +0,0 @@
-//
-// Created by david on 03.03.2026.
-//
-
-#ifndef LOCKSTEP_STEPDETECTOR_H
-#define LOCKSTEP_STEPDETECTOR_H
-
-#include "StepListener.h"
-#include "iir_filter.h"
-#include "ssf_filter.h"
-#include <vector>
-
-class StepDetector {
-protected:
-    StepListener *listener;
-    IirFilter f_highpass;
-    Filt f_neg;
-    SsfFilter f_ssf;
-    SsfStepDetector f_ssd;
-    RunningQualityFilter f_sqi;
-
-public:
-    StepDetector(StepListener *listener);
-    void filter(std::vector<float> values);
-};
-
-#endif //LOCKSTEP_STEPDETECTOR_H
diff --git a/app/src/main/cpp/jni_stepdetector.cpp b/app/src/main/cpp/jni_stepdetector.cpp
index 7f6a98d..6984141 100644
--- a/app/src/main/cpp/jni_stepdetector.cpp
+++ b/app/src/main/cpp/jni_stepdetector.cpp
@@ -3,7 +3,7 @@
 //
 
 #include <jni.h>
-#include "StepDetector.h"
+#include "step_detector.h"
 #include <new>
 #include <vector>
 
@@ -26,7 +26,7 @@ Java_at_lockstep_filter_StepDetector_native_1create(
         jclass /*unused*/, jlong engineHandle) {
     auto *listener = reinterpret_cast<StepListener *>(engineHandle);
     // We use std::nothrow so `new` returns a nullptr if the engine creation fails
-    auto *detector = new(std::nothrow) StepDetector(listener);
+    auto *detector = new(std::nothrow) StepDetector(60.0 /* FPS */, listener); // TODO
     return reinterpret_cast<jlong>(detector);
 }
 
diff --git a/app/src/main/cpp/libpasada b/app/src/main/cpp/libpasada
index b919e84..b333712 160000
--- a/app/src/main/cpp/libpasada
+++ b/app/src/main/cpp/libpasada
@@ -1 +1 @@
-Subproject commit b919e845c791069e8be9f8c6db299db53ddf1ac4
+Subproject commit b333712d9c9e1a7e41183b7794cc39ef64dd4612