Spatine,
In theory, one great advantage of subs is that they can be placed where they work best (against the walls) - which is almost always far from where main speakers work best (away from the walls). You lose this option when the subs and mains share a cabinet.
When bass is generated out away from the walls in a room, the omnidirectional, long wavelength signals (i.e. bass) will reflect back off the walls and cause cancellation (nulls, or dips in response) at some particular frequencies and reinforcement (peaks) at others. Near wall placement reduces this bass effect because the strongest reflected signal is virtually coincident with the original signal. There is nearly uniform reinforcement evenly across the sub's entire output, and you can adjust (lower, relative to free space placement) the output level of the sub accordingly. To (virtually) eliminate the remaining peaks and nulls, you can EQ, or try Duke's "distributed" system which provides flexibility in using one (or more) sub's peaks to offset the other subs' dips.
BTW, the other approach is to find mains that are designed to work up against (or inside) a wall. Shadorne's soffetted system is one approach, Roy Allison's designs have offered a variation on the theme for a long time.
The Deqx idea I mentioned in my previous post is simply a "brute force" EQ solution. It allows the peaks and nulls to develop and beats them into submission with EQ. Audyssey and Velodyne (among others) also make EQ products for this purpose.
BTW, I can't localize the (carefully integrated) subs in my EQ'd system, even though they're far from the main speakers. Of course, YMMV.
Good Luck
Marty
In theory, one great advantage of subs is that they can be placed where they work best (against the walls) - which is almost always far from where main speakers work best (away from the walls). You lose this option when the subs and mains share a cabinet.
When bass is generated out away from the walls in a room, the omnidirectional, long wavelength signals (i.e. bass) will reflect back off the walls and cause cancellation (nulls, or dips in response) at some particular frequencies and reinforcement (peaks) at others. Near wall placement reduces this bass effect because the strongest reflected signal is virtually coincident with the original signal. There is nearly uniform reinforcement evenly across the sub's entire output, and you can adjust (lower, relative to free space placement) the output level of the sub accordingly. To (virtually) eliminate the remaining peaks and nulls, you can EQ, or try Duke's "distributed" system which provides flexibility in using one (or more) sub's peaks to offset the other subs' dips.
BTW, the other approach is to find mains that are designed to work up against (or inside) a wall. Shadorne's soffetted system is one approach, Roy Allison's designs have offered a variation on the theme for a long time.
The Deqx idea I mentioned in my previous post is simply a "brute force" EQ solution. It allows the peaks and nulls to develop and beats them into submission with EQ. Audyssey and Velodyne (among others) also make EQ products for this purpose.
BTW, I can't localize the (carefully integrated) subs in my EQ'd system, even though they're far from the main speakers. Of course, YMMV.
Good Luck
Marty