The benefits of side firing woofers from the Coincident Speaker website.
"Mirror Imaged Side Firing Woofers - Advantages
Unlike the majority of other speaker companies that place their woofers on the front of their speakers, Coincident mounts their woofers on the side of the enclosures in a mirror imaged configuration.This is done because there are 3 distinct advantages with NO downside.
1. Elimination of Diffraction Effects -
Since the largest drivers,(the woofers), are mounted on the side of the enclosure, the front baffle can be made as narrow as the smaller midrange drivers, thereby eliminating diffraction effects, (which are responsible for impairing image width and creating high frequency smearing).
2. Flexibility of Speaker Placement -
Because the side firing woofers are mirror imaged, there are two positions to avoid room standing waves - woofers aiming to the inside or to the outside. In a room devoid of standing waves, (a very rare phenomenon), there would be absolutely no sonic difference whether the woofers were firing inside or outside, (so long as there is sufficient distance to the side wall in the case of outside firing). This is so because the crossover frequency to the woofers is so low, (typically 125 hz), where the wavelengths are very long, (in the range of 9 ft). This means that the woofers can be placed a distance as much as 9 ft away from the midrange units and still achieve seamless driver integration.
The Stereophile Show 2001 provides a dramatic real world illustration of the benefits of mirror imaged side firing woofers. The demonstration rooms were plagued with a standing wave centered at 100 hz ( elevated in amplitude by 12db!). This was the case when the Total Eclipse woofers were firing to the outside and as other exhibitors experienced, when the woofers were front facing . However, when the woofers aimed to fire to the inside, the room standing wave was avoided and flat frequency response to below 30 hz was achieved.
3. Simulation of Steep Crossover Slope-
Since high frequencies are directional, (low frequencies are not), aiming the woofers to the side of the listening position causes out of band high frequency information to be attenuated, thereby simulating an acoustical high pass filter. Therefore, the electrical first order crossover (chosen for reasons of purity and phase coherency- attenuates out of band frequencies at a rate of 6db per octave), of Coincident speakers act more like an acoustical third order slope (with its advantages of steeper attenuation- 18db per octave- of unwanted out of band high frequencies), but with no sonic penalty since no additional electrical components are added to the signal path."