Maybe getting the matching center and sub will help.
or some Bose 901
People really gave the SDA technology from Polk a fair chance. In the end, we're trying to reproduce 3D using 2D. IMHO, unless the sound engineers, who did the recordings, recorded in stereo for left/right and a time delay and volume (amount) of sound for each instrument for depth, then there would be no front to rear sound difference.