Even if the musician, his instrument, the loudspeaker and the lighting system are completely perfect and you still have a bad transmission... Could it really be that it's your cable? It can!
Like many musicians, we took our first musical steps in the small home studio or in the village combo and were already surprised at the result when we replaced the low budget jack plugs on the analog synth with decent metal plugs. Hum away, crack away. Or if you replaced the bell wire with a proper guitar cable... where do all the crystal clear highs and the "crispe sound" suddenly come from?