Sit in your comfy listening position, have someone measure the distance from the floor to your center ear. That is the height of your focal point of your speaker. Average is around 38 inches. Your PSB's are designed so the focal point should be the center between the top of the woofer cone and the bottom of the tweeter cone, That spot is the focal point of your woofer. In the example of 38 inches, that spot between your woofer and tweeter would need to be 38 inches off the ground.
Use a laser pointer, adjusted on the inside of the cabinet level with the focal point, turn your speakers in full tow making the laser point at your ears. Imaging should be excellent. If you have a brightness, start turning your tow outward exactly the same on left and right channels until sound is smooth. It is possible that at some point you may start losing center image, or dips in frequency, so stay keenly aware of image and frequency responce.
Use a laser pointer, adjusted on the inside of the cabinet level with the focal point, turn your speakers in full tow making the laser point at your ears. Imaging should be excellent. If you have a brightness, start turning your tow outward exactly the same on left and right channels until sound is smooth. It is possible that at some point you may start losing center image, or dips in frequency, so stay keenly aware of image and frequency responce.