A musical instrument, such as an acoustic guitar, and methods and apparatus for assembly of such a musical instrument. Data containing a plurality of symbols is received and a predetermined number of data samples are used to calculate an alignment error associated with the data samples. The tensioning ring includes a cylindrical rod with a turnbuckle that is rotated to increase the diameter of the tensioning ring. A related feature is the use of a digital flat-panel x-ray imager that employs a regular array of sensors to convert incident x-ray energy to a computer readable image, thereby permitting the fluoroscopic x-ray device to be used in any orientation without being affected by distortions due to local magnetic fields. Therefore, etching rate and CD uniformity can be improved during a semiconductor manufacturing process. A depth of the recess is predetermined such that the web portion formed by the recess will sever when a pressure differential between the different lobes exceeds a predetermined threshold.