Does anyone understand what happens to an analogue signal when it flows thru a speaker cable??
Sure. The resistance, capacitance, and inductance of the speaker cable all have effects on the signal.
How dramatic those effects are depend on the type of wire (copper v aluminum v silver etc...) the thickness of the wire, the length of the run, the proximity of the two conductors to one another, the quality of the insulation...
Tons of factors. Each one changes one value over another. Some matter more than others. *There is no perfect solution* is the most important thing to remember. Just solutions that prioritize one value over another.
Heavy gauge wire decreases resistance and inductance, but increases capacitance. Light gauge decreases capacitance, but increases inductance and resistance.
But there's more:
Speaker wire crossing another electrical cable (power, interconnect, etc) has a deleterious effect on the audio signal. Because now the two electrical signals are interacting with one another's magnetic fields.
There are so many variables, essentially there's no such thing as the "perfect" cable. It's all give and take regarding your signal.