Dear Ezio: +++++ " without hearing the same mastering pressed both ways, there's no way to know. " +++++
this Rushton statement makes a lot of sense, anyway this is what you can read on a Clarity Recordings LP ( one of the one side LP I own. ):
" Most reords are produced from a set of stampers that press the groove structure onto both sides on the vinyl disc. When the needle traces the grooves on the top side of the dis, it is affected by the vibration of the groove structure on the reverse side.
In disc reproduction, sound is produced by the vibration of the stylus in the grooves cut in the disc. Extremely minute signals are amplified by the cartridge and than sent to the phono equalization circuit of the pre-amplifier where a tremendous amount of gain and equalization is required to produce a line level signal for the amplifier. Any small amount of signal degradation or unwanted information, which is sensed by the tip of the stylus will be amplified enormously.
Another problem in conventional double sided records is that the reverse side of the disc has areas with and with out cut grooves. There is also a variation in sensed areas with land ( or flat surfaces ) and areas with air pockets ( caused by the cutting of the grooves ). This results in a constant variation of information that is being sensed by the stylus and added to the basic information from the groove structure on the top of the dis. The end result is an audible blurring of all reproduced sound.
Single sided records also have an extremely flat reverse side. They bond much more accurately to the surface of the platter of the turntable and provide the most stable platform for the tracing of record grooves cut on the top side of the dis. "
Well, unfortunately I don't own/have the same Clarity double sided recording.
Regards and enjoy the music.
Raul.