New Bass & Treble strings are installed while properly tuning the duplex ranges and muting the unvoiced sections with premium felts. The difference between a good and a great stringing of a piano is extremely significant. The overtones should be brilliant and false beats should be eradicated. The termination point of each speaking length should be precise in order for the strings to vibrate cleanly. The sustain should bloom.
To a piano technician, stringing a piano is a skill that takes many years to perfect. It only comes with continual repetition and is a talent that some technicians base their whole career on.