Multi-carrier Offsets are used for large sectors and engineers usually manage that. Audible result is a kind of 'phasing'. ATCOs have control of cross-coupling of transceivers on different freqs ('re-transmit') used when combining sectors ('bandboxing'). It often does not have the desired effect, and the side-tones used to be awful. I hope they have improved because I found them to be a deterrent to bandboxing.