Resolves issue with correct display and scaling of decibel values in

both the spectral and waterfall displays.

Resolves issue with gain loss in HilbertTransform.

src/spectrum/converter/RealDecibelConverter.java

@@ -7,33 +7,22 @@ public class RealDecibelConverter extends DFTResultsConverter
 {
 	private static final Logger mLog = LoggerFactory.getLogger( RealDecibelConverter.class );
 
-	private float mDynamicRangeReference;
-
 	public RealDecibelConverter()
 	{
-		setSampleSize( 24.0 );
 	}
 	
-	/**
-	 * Specifies the bit depth to establish the maximum dynamic range.  All
-	 * FFT bin values will be scaled according to this value.
-	 */
-	@Override
-	public void setSampleSize( double size )
-	{
-		assert( 2.0 <= size && size <= 32.0 );
-		
-		mDynamicRangeReference = (float)Math.pow( 2.0d, size );
-	}
-
 	/**
 	 * Converts the output of the JTransforms FloatFFT_1D.realForward()
 	 * calculation into a normalized power spectrum in decibels, per description
 	 * in Lyons, Understanding Digital Signal Processing, 3e, page 141.
+	 * 
+	 * Note: this is only calculating the lower half of the spectrum
 	 */
 	@Override
     public void receive( float[] results )
     {
+		float dftScalor = 1.0f / (float)( results.length ^ 2 );
+		
 		float[] processed = new float[ results.length / 4 ];
 
 		int index = 0;
@@ -42,12 +31,9 @@ public class RealDecibelConverter extends DFTResultsConverter
 		{
 			index = x * 2;
 			
-			float normalizedMagnitude = 10.0f * (float)Math.log10( 
+			processed[ x ] = 20.0f * (float)Math.log10( 
 				( ( results[ index ] * results[ index ] ) + 
-				  ( results[ index + 1 ] * results[ index + 1 ] ) ) / 
-				  		mDynamicRangeReference );
-
-			processed[ x ] = normalizedMagnitude;
+				  ( results[ index + 1 ] * results[ index + 1 ] ) ) * dftScalor );
 		}
 
 		dispatch( processed );