why are two subs harder to place than full range?

I'm getting a second sub for a rather large vaulted room, have an injured back, and would rather minimize what seems like a rather long process, at least for the time being by just keeping the subs with the mains.

The best spot is often away from the corner and close to the side wall and a few feet in front of your main speakers (assuming you have full range) I find the best way to integrate is to run the main speakers full range if they are big bad boys with big sub sized woofers themselves.

I would never place a sub or main speakers in the corner unless you want pure impact for HT - as you are talking room modes galore...

Although I'm only using one sub I did quite a bit of experimenting with placement. The corner placement was the worst for me. My sub is between the speakers with the driver on the same plane. By far the smoothest integration.

The sub brings almost as many problems as it solves. To give you peace of mind connect the system to a room correction device. Some not only measure and EQ to compensate for the acoustics, but will act as a crossover too.

Some are simpler than others to use. I can recommend the Lyngdorf room perfect system for its ease of set up and excellent sonics. It will save a lot of fiddling about. Speaker placement is then irrelevant.

Good subwoofers belong in the corners of your room so they can properly load it. Your mains belong out further into the room to avoid boundary effects(study 'The Allison Effect'). The problem then is the time alignment between the subs and the mains. The better active subs have time and phase adjustments that enable one to align the system in the time domain, or a unit such as the TacT RCS 2.2XP or Lyngdorf Room Perfect System can be used. Here's something that may interest you: (http://www.linkwitzlab.com/frontiers_5.htm)

the problem is not one of subwoofer placement; separate subwoofers are easier to place correctly than full range speakers. the problem is integration. unless the subs perfectly integrate with the 'other' speakers seamlessly, perfect placement has limited value.

we are speaking here of 2-channel music only listening......HT DSP LFE channel subwoofers are a different issue.

the problem is somehow getting the crossover for both the sub and the main speaker to work as if they were designed as one unit. also to have the character of the main speaker and amp to be captured by the sub. most normal speakers do not have a low frequency cutoff or way to vary the low frequency extension. therefore you generally need an outboard crossover; which typically reduces refinement and adds complexity (or digitizes everything....bad, bad, bad)

lots of people do run separate subs and like them; i've yet to hear a system like that integrate to my likeing.....but i suppose it is possible. note i am not saying that i don't like systems with separate subs; only that they lack the level of mid-range--mid-bass integration the very best systems have.

i prefer built-in subs which ARE designed into my speakers and give me 10hz extension AND seamless integration. i don't have as much flexibility in location; but i have lots of subwoofer adjustments to help the bass integrate with the room.

integration.....not location....is the real challenge.