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diff --git a/src/com/jsyn/unitgen/SquareOscillatorBL.java b/src/com/jsyn/unitgen/SquareOscillatorBL.java
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+/*
+ * Copyright 2009 Phil Burk, Mobileer Inc
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ * 
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ * 
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package com.jsyn.unitgen;
+
+import com.jsyn.engine.MultiTable;
+
+/**
+ * Band-limited square wave oscillator. This requires more CPU than a SquareOscillator but is less
+ * noisy at high frequencies.
+ * 
+ * @author Phil Burk (C) 2009 Mobileer Inc
+ */
+public class SquareOscillatorBL extends SawtoothOscillatorBL {
+    @Override
+    protected double generateBL(MultiTable multiTable, double currentPhase,
+            double positivePhaseIncrement, double flevel, int i) {
+        double val1 = multiTable.calculateSawtooth(currentPhase, positivePhaseIncrement, flevel);
+
+        /* Generate second sawtooth so we can add them together. */
+        double phase2 = currentPhase + 1.0; /* 180 degrees out of phase. */
+        if (phase2 >= 1.0)
+            phase2 -= 2.0;
+        double val2 = multiTable.calculateSawtooth(phase2, positivePhaseIncrement, flevel);
+
+        /*
+         * Need to adjust amplitude based on positive phaseInc. little less than half at
+         * Nyquist/2.0!
+         */
+        final double STARTAMP = 0.92; /* Derived by viewing waveforms with TJ_SEEOSC */
+        double scale = STARTAMP - positivePhaseIncrement;
+        return scale * (val1 - val2);
+    }
+}