Harpsichord begins very much like an enlarged spinet: with larger case, greater soundboard, more as well as longer strings. 
   
Spinet 
V.S
Harpsichord

It produces a harsh, raw, nasal as well as disturbing tone which makes it unsuitable on behalf of solo performances. In order to improve or solve this situation, numerous experiments were conducted such as adding pedals, stops as well as other devices to mimic other instruments.  
From all these experiments, 4 devices were formulated to solve this problem:-         forte stop: lift dampers-         soft stop: press the dampers on to the strings to stop vibration-         buff stop: to insert soft cloth or leather between the jacks as well as strings-         shifting stop: shifts entire keyboard
Mechanism
 
Caption: Schematic view of a 2×8” single manual harpsichord. 1) keylever, 2) name batten, 3) name board 4) tuning pins, 5) nut, 6) jack rail, 7) upper registers, 8 ) string, 9) bridge, 10) hitchpin, 11) liner, 12) bentside/tail, 13) boudin, 14) soundboard, 15) gap, 16) upper belly rail, 17) jack, 1  lower belly rail, 19) bottom, 20) rack, 21) guide pin, 22) lower registers, 23) wrestplank, 24) balance pin, 25) keyboard frame.  

Development
Harpsichord makers gradually increased the size of the harpsichord as long as 16 feet. Thin wires were used as the casings were not in a position to tolerate heaving wires. The quill plectra could not vibrate them as well. They soon realized that long as well as thin wires produce unmusical tone as well as hence reduce the size between 8 to 10 feet. They also increased the number of strings to each note to enhance the timbre of the harpsichord.


Venice was the center of its manufacture. At that time its prevailing shape was winglike, similar to that of a grand piano. The square harpsichord, often referred to as spinet, became more common in the late 16th cent., when harpsichord making in the northern countries surpassed that of Italy. Perhaps the greatest craftsmen were the Ruckers family of Antwerp (late 16th–17th cent). By the 1750s, the centre of harpsichord manufacturing has shifted to Paris. The more well-known makers are the ancestors of Elizabeth Claude Jacquet, Jean as well as Claude Jacquet. They took on the business from the Blanchet family who began making harpsichords since 1689. Hence, the harpsichord was once again modified under the hands of the Parisians. The instrument was standardized to be a two-manual instrument. The lower keyboard contains 2 sets of strings: a set of 8’ as well as another of 4’. The upper keyboard contains a separate set of 8’ strings. Interestingly, both keyboards, with the utilize of a coupler, can be made to play together, thus extending the range of the harpsichord. They also used three strings to each note.