chunkSpan = new Span( insertPos + framesWritten, insertPos + framesWritten + chunkLen );
if( framesWritten < preLen ) { // fade this out
chunkLen2 = (int) Math.min( chunkLen, preLen - framesWritten );
deltaChunk = chunkLen - chunkLen2;
chunkSpan2 = deltaChunk > 0 ? chunkSpan.replaceStop( chunkSpan.stop - deltaChunk ) : chunkSpan;
//System.err.println( "B this.readFrames( mixBuf, 0, " + chunkSpan2 + " )" );
this.readFrames( mixBuf, 0, chunkSpan2 );
//System.err.println( "B bc.fadeOut : mixBuf in [ 0 ... " + chunkLen2 + " ], offset = "+framesWritten );
bcPre.fadeOut( framesWritten, mixBuf, 0, mixBuf, 0, chunkLen2 );
for( int i = 0; i < mixBuf.length; i++ ) {