The tailpiece that the strings are attached to have a huge impact on the sound of an instrument.
The materials used, built in or added on fine tuners and the positioning of it in relation to the stop length is critical. Even the choice of tail gut has an influence on the sonic response of the instrument.
For example if you were to tap on a metal tailpiece you will be able to hear the metallic sound that rings through the instrument. Similarly, with a chunky soft wood tailpiece you will find the sound dull and unresponsive. That said, if the tailpiece is a chunky softwood cheapie (often found on entry level factory instruments) but attached with a piece of Kevlar gut or thin steel wire, the probability of you finding the sound and responsiveness increased will be evident.
The weight of the tailpiece is also a factor to take into consideration. If it is heavy it will slow responsiveness. By adding a set of four metal fine tuners will make the instrument’s response noticeably slower. Additionally, it will reduce the string length between the back of the bridge and tailpiece therefore changing the harmonic tuning. If the tail gut can be or has been shortened to compensate for this it will improve the sound. If there is a choice, choose a plastic tailpiece with built in fine tuners over metal to avoid a tin sound.
The ideal is to have a wooden tailpiece made from select wood with built in fine tuners. The typical types of wood used are Ebony, Rosewood and Boxwood although others are also used depending on taste and availability.