diff --git a/sndlock.cpp b/sndlock.cpp
index e653f86..b1cdf41 100644
--- a/sndlock.cpp
+++ b/sndlock.cpp
@@ -18,8 +18,8 @@
 #define SND_BUFLEN 4096
 
 static std::atomic<bool> shutdown_threads;
-static std::atomic<float> frequency[SND_PCHAN];
-static std::atomic<float> lpf_bandwidth[SND_PCHAN];
+static std::atomic<double> frequency[SND_PCHAN];
+static std::atomic<double> lpf_bandwidth[SND_PCHAN];
 
 static std::mutex lpf_hist_mutex;
 static float lpf_hist[SND_PCHAN][512];
@@ -64,7 +64,7 @@ static void dsp_thread()
     size_t buf_out_idx = SND_BUFLEN*SND_PCHAN;
 
     uint32_t phase_in[SND_PCHAN] = { 0 };
-    std::complex<float> lpf_y[SND_PCHAN];
+    std::complex<double> lpf_y[SND_PCHAN];
     int lpf_count[SND_PCHAN] = { 0 };
 
     nfds_t nfds = sio_nfds(hdl);
@@ -75,18 +75,18 @@ static void dsp_thread()
         int revents = sio_revents(hdl, pfd);
 
         uint32_t ftw[SND_PCHAN];
-        float lpf_k[SND_PCHAN];
+        double lpf_k[SND_PCHAN];
         for(int i=0;i<SND_PCHAN;i++) {
-            ftw[i] = frequency[i]*(float)UINT32_MAX/SND_RATE;
-            lpf_k[i] = 2.0f*(float)M_PI*lpf_bandwidth[i]/SND_RATE;
+            ftw[i] = frequency[i]*(double)UINT32_MAX/SND_RATE;
+            lpf_k[i] = 2.0*M_PI*lpf_bandwidth[i]/SND_RATE;
         }
 
         if(revents & POLLOUT) {
-            float scale = powf(2.0f, SND_BITS-1) - 1.0f;
+            double scale = pow(2.0, SND_BITS-1) - 1.0;
             if(buf_out_idx == SND_BUFLEN*SND_PCHAN) {
                 for(int i=0;i<SND_PCHAN;i++)
                     for(int j=0;j<SND_BUFLEN;j++) {
-                        buf_out[2*j+i] = scale*sinf(phase_out[i]*2.0f*(float)M_PI/(float)UINT32_MAX);
+                        buf_out[2*j+i] = scale*sin(phase_out[i]*2.0*M_PI/(double)UINT32_MAX);
                         phase_out[i] += ftw[i];  // wraps on overflow
                     }
                 buf_out_idx = 0;
@@ -98,15 +98,15 @@ static void dsp_thread()
         if(revents & POLLIN) {
             int16_t buf_in[SND_BUFLEN];
             size_t read = sio_read(hdl, buf_in, sizeof(buf_in));
-            float scale = powf(0.5f, SND_BITS-1);
+            double scale = pow(0.5, SND_BITS-1);
             for(int i=0;i<SND_PCHAN;i++)
                 for(int j=0;j<read/sizeof(buf_in[0]);j++) {
-                    std::complex<float> rotated;
-                    rotated = (float)buf_in[j]*std::polar(scale, phase_in[i]*2.0f*(float)M_PI/(float)UINT32_MAX);
+                    std::complex<double> rotated;
+                    rotated = (double)buf_in[j]*std::polar(scale, phase_in[i]*2.0*M_PI/(double)UINT32_MAX);
                     phase_in[i] += ftw[i];  // wraps on underflow
 
                     lpf_y[i] += (rotated - lpf_y[i])*lpf_k[i];
-                    float mag = std::abs(lpf_y[i]);
+                    double mag = std::abs(lpf_y[i]);
 
                     lpf_count[i]++;
                     if(lpf_count[i] == 200) {
@@ -165,8 +165,8 @@ int main(int argc, char* argv[])
     std::atexit(ImGui_ImplOpenGL3_Shutdown);
 
     for(int i=0;i<SND_PCHAN;i++) {
-        frequency[i] = 441.0f + 202.0f*i;
-        lpf_bandwidth[i] = 10.0f;
+        frequency[i] = 441.0 + 202.0*i;
+        lpf_bandwidth[i] = 10.0;
     }
 
     static std::thread dsp_thread_h = std::thread(dsp_thread);