diff --git a/cmd/main.cpp b/cmd/main.cpp
index 38fb14d..20847dc 100644
--- a/cmd/main.cpp
+++ b/cmd/main.cpp
@@ -2,10 +2,6 @@
 
 #include <iostream>
 #define LOG_EXPR(expr) std::cout << #expr << " = " << (expr) << "\n";
-std::ostream& operator<<(std::ostream& output, const signalsmith::MemoryTracker& memory) {
-	output << "{.allocBytes=" << memory.allocBytes << ", .freeBytes=" << memory.freeBytes << ", .current=" << memory.currentBytes << "}";
-	return output;
-}
 
 #include <ctime>
 
@@ -29,8 +25,12 @@ int main(int argc, char* argv[]) {
 	if (!inWav.read(inputWav).warn()) args.errorExit("failed to read WAV");
 	size_t inputLength = inWav.samples.size()/inWav.channels;
 	
-	Wav prevWav;
-	prevWav.read(outputWav); // to verify it's the same output
+	Wav prevWav; // Used during development, to compare against known-good previous render
+	if (!prevWav.read(outputWav + "-reference.wav")) {
+		if (prevWav.read(outputWav)) {
+			prevWav.write(outputWav + "-reference.wav");
+		}
+	}
 
 	Wav outWav;
 	outWav.channels = inWav.channels;
@@ -102,7 +102,7 @@ int main(int argc, char* argv[]) {
 		}
 		diff2 /= prevWav.samples.size();
 		double diffDb = 10*std::log10(diff2);
-		LOG_EXPR(diffDb);
-		if (diffDb > -60) std::cerr << "too much difference\n";
+		std::cout << "Difference from reference: " << diffDb << " dB\n";
+		if (diffDb > -60) args.errorExit("too much difference\n");
 	}
 }
diff --git a/cmd/util/memory-tracker.hxx b/cmd/util/memory-tracker.hxx
index b568ab1..9fcee7d 100644
--- a/cmd/util/memory-tracker.hxx
+++ b/cmd/util/memory-tracker.hxx
@@ -1,9 +1,9 @@
 #include "./memory-tracker.h"
 
-static size_t memoryTrackerAllocCounter = 0;
-static size_t memoryTrackerFreeCounter = 0;
-
-signalsmith::MemoryTracker::MemoryTracker() : signalsmith::MemoryTracker::MemoryTracker(memoryTrackerAllocCounter, memoryTrackerFreeCounter) {}
+#if !defined(__has_include) || !__has_include(<dlfcn.h>)
+// Fallback if we don't have <dlfcn.h>, which we use to get the existing methods
+signalsmith::MemoryTracker::MemoryTracker() : signalsmith::MemoryTracker::MemoryTracker(0, 0) {}
+#else
 
 #include <cstdlib>
 #include <cstddef>
@@ -11,6 +11,13 @@ signalsmith::MemoryTracker::MemoryTracker() : signalsmith::MemoryTracker::Memory
 #include <cassert>
 #include <utility>
 
+namespace signalsmith {
+
+namespace memory_tracker {
+
+static size_t memoryTrackerAllocCounter = 0;
+static size_t memoryTrackerFreeCounter = 0;
+
 static void * (*originalCalloc)(size_t, size_t) = nullptr;
 static void * (*originalMalloc)(size_t) = nullptr;
 static void * (*originalRealloc)(void*, size_t) = nullptr;
@@ -31,7 +38,7 @@ auto callOriginal(Fn& fn, const char *symbolName, Args &&...args)
 	return fn(std::forward<Args>(args)...);
 }
 
-static constexpr size_t EXTRA_SIZE = sizeof(std::max_align_t)*2;
+static constexpr size_t extraInfoBytes = sizeof(std::max_align_t)*2;
 void * storeAllocInfo(void *offsetPointer, void *originalPointer, size_t size) {
 	if (!originalPointer) return nullptr;
 	memoryTrackerAllocCounter += size;
@@ -53,34 +60,36 @@ void * getAllocPointer(void *ptr) {
 	return (void *)sizePtr[-1];
 }
 
+}} // namespaces
+
 extern "C" {
 	void * malloc(size_t size) {
-		void *ptr = callOriginal(originalMalloc, "malloc", size + EXTRA_SIZE);
-		return storeAllocInfo((unsigned char *)ptr + EXTRA_SIZE, ptr, size);
+		void *ptr = signalsmith::memory_tracker::callOriginal(signalsmith::memory_tracker::originalMalloc, "malloc", size + signalsmith::memory_tracker::extraInfoBytes);
+		return signalsmith::memory_tracker::storeAllocInfo((unsigned char *)ptr + signalsmith::memory_tracker::extraInfoBytes, ptr, size);
 	}
 
 	void * calloc(size_t size, size_t count) {
-		size_t extraCount = (EXTRA_SIZE + size - 1)/size; // enough extra items to store what we need
-		void *ptr = callOriginal(originalCalloc, "calloc", size, count + extraCount);
-		return storeAllocInfo((unsigned char *)ptr + size*extraCount, ptr, size*count);
+		size_t extraCount = (signalsmith::memory_tracker::extraInfoBytes + size - 1)/size; // enough extra items to store what we need
+		void *ptr = signalsmith::memory_tracker::callOriginal(signalsmith::memory_tracker::originalCalloc, "calloc", size, count + extraCount);
+		return signalsmith::memory_tracker::storeAllocInfo((unsigned char *)ptr + size*extraCount, ptr, size*count);
 	}
 
 	void * realloc(void *ptr, size_t size) {
-		void *originalPtr = getAllocPointer(ptr);
+		void *originalPtr = signalsmith::memory_tracker::getAllocPointer(ptr);
 		auto pointerOffset = (unsigned char *)ptr - (unsigned char *)originalPtr;
-		size_t originalSize = getAllocSize(ptr);
-		memoryTrackerFreeCounter += originalSize;
+		size_t originalSize = signalsmith::memory_tracker::getAllocSize(ptr);
+		signalsmith::memory_tracker::memoryTrackerFreeCounter += originalSize;
 		
-		ptr = callOriginal(originalRealloc, "realloc", originalPtr, size + pointerOffset);
-		return storeAllocInfo((unsigned char *)ptr + pointerOffset, ptr, size);
+		ptr = signalsmith::memory_tracker::callOriginal(signalsmith::memory_tracker::originalRealloc, "realloc", originalPtr, size + pointerOffset);
+		return signalsmith::memory_tracker::storeAllocInfo((unsigned char *)ptr + pointerOffset, ptr, size);
 	}
 
 	void free(void *ptr) {
-		void *originalPtr = getAllocPointer(ptr);
-		size_t originalSize = getAllocSize(ptr);
-		memoryTrackerFreeCounter += originalSize;
+		void *originalPtr = signalsmith::memory_tracker::getAllocPointer(ptr);
+		size_t originalSize = signalsmith::memory_tracker::getAllocSize(ptr);
+		signalsmith::memory_tracker::memoryTrackerFreeCounter += originalSize;
 
-		callOriginal(originalFree, "free", originalPtr);
+		signalsmith::memory_tracker::callOriginal(signalsmith::memory_tracker::originalFree, "free", originalPtr);
 	}
 }
 
@@ -101,3 +110,7 @@ void operator delete(void *ptr) noexcept {
 void operator delete[](void *ptr) noexcept {
 	free(ptr);
 }
+
+signalsmith::MemoryTracker::MemoryTracker() : signalsmith::MemoryTracker::MemoryTracker(signalsmith::memory_tracker::memoryTrackerAllocCounter, signalsmith::memory_tracker::memoryTrackerFreeCounter) {}
+
+#endif // check for <dlfcn.h>
diff --git a/cmd/util/wav.h b/cmd/util/wav.h
index 496e197..a2396c8 100644
--- a/cmd/util/wav.h
+++ b/cmd/util/wav.h
@@ -54,14 +54,6 @@ public:
 		std::string reason;
 		
 		Result(Code code, std::string reason="") : code(code), reason(reason) {};
-		Result(const Result &other) = default;
-		Result & operator=(const Result &other) {
-			if (code == Code::OK) {
-				code = other.code;
-				reason = other.reason;
-			}
-			return *this;
-		}
 		// Used to neatly test for success
 		explicit operator bool () const {
 			return code == Code::OK;