Skin effect appears to be the phonomenon in play in this situation. Laws of physics such as the skin effect apply at any frequences. It is a gradual effect. Skin effect dictate that as the frequency rises the singal si moved towards the outside of the conductors. The skin dept is defined as the dept, from the surface, at which the current density is about 37% that of the surface, for copper at 20 hz it is about 50 mm and at 20kHz it is about .6 mm. The effect at audio frequency is that as the high frequencies are traveling in a narrower regions than the low frequency the high frequency are submitted to a larger resistance that the low freqencies and thus suffer more attenuation in the cable.
Hence with regard to the OP, the Analysis Plus cables appears to have conductors of smaller diametres than the 14/2, such that there is more skin effect in the 14/2 than the Analysis Plus cables witch translate to the OP comment where the 14/2 lack a bit of the high end compare to the Analysis Plus. Skin effect applies to audio frequency as it dictates the frequency balance of a cable.
Hence with regard to the OP, the Analysis Plus cables appears to have conductors of smaller diametres than the 14/2, such that there is more skin effect in the 14/2 than the Analysis Plus cables witch translate to the OP comment where the 14/2 lack a bit of the high end compare to the Analysis Plus. Skin effect applies to audio frequency as it dictates the frequency balance of a cable.