So the expert here in the video is using a digital term to describe motions which are actually shear waves that are cut into the the vinyl.. The stylus tracks those inscribed shear waves and converts that motion into an electrical signal. A speaker also has motion and therefore shear waves created at the launch of the voice coil...all that motion and and shear travels on both side of the cone at the same time as well as thru the material.
A record responds much like a cone in motion..2 sides vibrating one being the dominant surface... the shear waves travel on and thru both. The styus reacts to the shear on both material sides and hears both sides. The stylus also hears a polarity of shear that travels on the surface hits the paper center and is reflected back at the stylus. The same happens when energy is reflected from the lip of the record back at the stylus.
None of this happens at the same time.
The intended signal is being corrupted by the constant shift of polarity which are mechanical waves known as shear waves. A reduction in shear wave interference is what needs to be understood in order to reduce overall distortion. Jitter term is used because some do not know of or understand shear wave motion. Tom
A record responds much like a cone in motion..2 sides vibrating one being the dominant surface... the shear waves travel on and thru both. The styus reacts to the shear on both material sides and hears both sides. The stylus also hears a polarity of shear that travels on the surface hits the paper center and is reflected back at the stylus. The same happens when energy is reflected from the lip of the record back at the stylus.
None of this happens at the same time.
The intended signal is being corrupted by the constant shift of polarity which are mechanical waves known as shear waves. A reduction in shear wave interference is what needs to be understood in order to reduce overall distortion. Jitter term is used because some do not know of or understand shear wave motion. Tom