diff --git a/DeepDrftTests/AudioProcessorTests.cs b/DeepDrftTests/AudioProcessorTests.cs
index 0fd5223..04cce45 100644
--- a/DeepDrftTests/AudioProcessorTests.cs
+++ b/DeepDrftTests/AudioProcessorTests.cs
@@ -74,6 +74,14 @@ public class AudioProcessorTests
         Assert.That(ReadFmtAudioFormat(audio.Buffer), Is.EqualTo(WaveFormatPcm));
         // 4 float samples (4 bytes each) → 4 PCM samples (3 bytes each) = 12 data bytes after the 44-byte header.
         Assert.That(audio.Buffer.Length, Is.EqualTo(44 + 12));
+        // Verify the converted sample values: (int)(sample * 8388607.0), clamped, little-endian 3 bytes.
+        // 0.5f  → 4194303  = 0x3FFFFF → FF FF 3F
+        // -0.5f → -4194303 = 0xFFC00001 → 24-bit LE: 01 00 C0
+        // 1.0f  → 8388607  = 0x7FFFFF → FF FF 7F
+        // -1.0f → -8388607 = 0xFF800001 → 24-bit LE: 01 00 80
+        var expectedData = new byte[] { 0xFF, 0xFF, 0x3F, 0x01, 0x00, 0xC0, 0xFF, 0xFF, 0x7F, 0x01, 0x00, 0x80 };
+        var actualData = audio.Buffer[44..];
+        Assert.That(actualData, Is.EqualTo(expectedData), "Float samples must be converted to 24-bit PCM correctly");
     }
 
     [Test]
@@ -93,6 +101,14 @@ public class AudioProcessorTests
         Assert.That(ReadFmtAudioFormat(audio.Buffer), Is.EqualTo(WaveFormatPcm));
         // 4 container samples (4 bytes each) → 4 PCM samples (3 bytes each) = 12 data bytes.
         Assert.That(audio.Buffer.Length, Is.EqualTo(44 + 12));
+        // Verify the repacked sample values: lowest 3 bytes of each 4-byte little-endian container.
+        // 0x123456     → LE 4 bytes: 56 34 12 00 → keep 3: 56 34 12
+        // 0xFFEDCBA9   → LE 4 bytes: A9 CB ED FF → keep 3: A9 CB ED
+        // 0x000001     → LE 4 bytes: 01 00 00 00 → keep 3: 01 00 00
+        // 0xFF800000   → LE 4 bytes: 00 00 80 FF → keep 3: 00 00 80
+        var expectedData = new byte[] { 0x56, 0x34, 0x12, 0xA9, 0xCB, 0xED, 0x01, 0x00, 0x00, 0x00, 0x00, 0x80 };
+        var actualData = audio.Buffer[44..];
+        Assert.That(actualData, Is.EqualTo(expectedData), "Padded 24-in-32 samples must strip the padding byte correctly");
     }
 
     [Test]
@@ -123,6 +139,26 @@ public class AudioProcessorTests
         Assert.That(audio!.Duration, Is.EqualTo(180.0), "Undersized EXTENSIBLE fmt chunk must fall back to default metadata");
     }
 
+    [Test]
+    public void TryExtractPcm_FloatWav_ReturnsNull()
+    {
+        var subFormat = SubFormatGuid(0x0003);
+        var wav = BuildMinimalWav(channels: 2, sampleRate: 44100, bitsPerSample: 32, audioFormat: WaveFormatExtensible,
+            subFormatGuid: subFormat, validBitsPerSample: 32);
+        var result = new AudioProcessor().TryExtractPcm(wav);
+        Assert.That(result, Is.Null);
+    }
+
+    [Test]
+    public void TryExtractPcm_Padded24in32_ReturnsNull()
+    {
+        var subFormat = SubFormatGuid(WaveFormatPcm);
+        var wav = BuildMinimalWav(channels: 2, sampleRate: 44100, bitsPerSample: 32, audioFormat: WaveFormatExtensible,
+            subFormatGuid: subFormat, validBitsPerSample: 24);
+        var result = new AudioProcessor().TryExtractPcm(wav);
+        Assert.That(result, Is.Null);
+    }
+
     // -- helpers --------------------------------------------------------------------------------
 
     /// <summary>