To have a really good theater experience in your home you have to have a subwoofer. No doubt about it. So what should you look for when you are looking to add a sub to your home setup?The first is to decide on whether you want an active or passive sub. An active sub has a built in amplifier which means you don't have to power it off your main amp and can dedicate those channels to your full range speakers. A passive sub is exactly what the name implies. A subwoofer without an internal amplifier requiring an external amplification source. What else should we consider for our subwoofer purchase? Like with all speaker purchases everyone has their own preference when it comes to sound quality, but the following should help you interpet what you are hearing.
The feeling that the bass is integrated without being able to tell where it is coming from
Good pitch definition. For example, low notes on an upright bass or pedal notes of an organ.
Size. This is dependant on your room size. There is no scientific answer to this one. If you think the size you are listening to is loud enough at the dealer and the listening room is comparable in size to your space, you should be ok.
Placement. Make sure it is separated from items that may buzz from the vibration, but a safe bet is near the speakers at the front of the room.
One sub or two? This depends on how picky you are, but 2 subs have the ability to even out irregularities in the sound caused by the listening environment, i.e. room.