does this NOT work ? 
in my head you could add and add and combine the sweet bajezzus out of cables … seems to lose some signal (or i am just too n00b) …thanks for all tips !
Depending on the quality of the connections and each cable involved there could be some added resistance issues, otherwise you should be fine temporarily.
But I would suggest you invest in a couple of Y-cables (usually in stores as insert-cables). It’s just more convenient.