Subwoofers masking other frequencies.


Bought a third sub,a svs sb2000 to add to my existing 2 subs hoping for stronger and more detailed bass response. My mains are magnapan 1.7i driven by parasound A21 +. After messing around with  different ways to intergrate the subs I realized some parts of the music was missing or reduced in volume or one channel was stronger .well I turned off one sub at a time and the sound was full. Is this common and what's the remedy for this phenomenon. 
Thanks 




audiomaze
@audiomaze 
Yes, Audyssey will help you, but it is still a starting point. I don’t think it does much in the time domain. You will need to raise the level a couple of dBs from what Audyssey recommends for it to sound realistic. Good luck. 
This is about the phase control you know you’re in phase when all your speakers are moving in and out exactly at the same time.To do this you simply move the phase knob from 0 to 180 until You achieve the loudest sound then you are in phase. Hope this helps.Best of luck
While it's true that you'll get the loudest sound in the crossover region when the sub is "in phase" with the main speakers, that may not be what sounds best.  IF one of the issues is too much contribution from the sub in and above the crossover region, then partial cancellation may actually sound better, which is why I said that "when it sounds right it IS right".   

Duke
Audiomaze - what are your existing two subs?   Also, are you using an SB-2000 or the newer SB-2000 Pro?