1 good sub is enough unless you have a ridiculous sized room. Most problems come from placement and room gain. Two subs can fight this but at added costs. Just move a single good sub to a best place and treat the room. The only true accurate way to go. And ported will get you lower, and no advantage over sealed. All depends on the design and quality. Room correction has come a long way and it will only get better. Remember absorption for room correction can be frequency selective, acting like an equalizer and changing the original sound. Diffusion can scatter the reflections without taking away or adding to resonances in the room, making certain frequencies louder or softer. So you have to research the room you are in and the decay rate RT60 and use a computer and a microphone and nail it in. Get the first curve and fine tune it to more accurate. Plenty of free software to do room correction. Good luck
Go dual small sub, switch to closed sub or buy a bigger sub?
I bought my first sub 2 months ago: an SVS PB-1000 and I loved it .. at first. Maybe I have a case of upgrade-itis but I want more/better/different without being able to pinpoint what I want.
I have the PB-1000 running in my livingroom (128 cubic meter or around 4500 cubic feet) and I ran the Audyssey EQ. It seems there is a lot of headroom (gain is at 50% and audyssey still set the subwoofer trim to -5db) .. but since so many people seem to prefer bigger subs I fear I am missing out on something. Should I consider buying another PB-1000 and perhaps experience the magic of dual subs people proclaim or should I just go closed sub rather than ported sub since I prefer music over tv/movies, and then simply get a bigger one e.g. SB-4000?
Note: I am not in the US, so no SVS trade-in upgrade option unfortunately.