Tomsch , I used to have one sub only? Like you I wonder if I will add more sub? I thought SWARM system of audiokinesis would be a phenomenal addition, unfortunately I have no more room for extra Amp nd four sub.Knowing that the modified pioneer sub are excellent? I bought a pair from a guy in UTah . Once I was able to integrate them on my system? There is no going back.The KLH model 9 did became more holographic and instruments sounded natural with weight.yes if you have room 2 or 3 or even 4 is good.
Did you ever buy too much bass?
I talk a lot about bass and integration of subwoofers in a system and I realized that I need to hear more about the experiences auidphiles have when they go buy speakers and put them in a room. Did you look at specs? Did you audition in the home? Did you end up with too little or too much bass compared to what you were expecting??