Hi Patchwork,
Just to keep things on track here, the dispersion of the tweeter on the QS4 and QS8 isn't significantly different. The dome is the same size on both but the voice-coil of the QS8 tweeter is 1 inch (compared to 1/2-inch on the QS4) so its power handling is cleaner and better and a lower crossover frequency can be used (2.7 kHz vs. 4.3 kHz). The QS8 also has larger woofers with greater bass extension than the QS4.
Good advice from all on tweaking the placement of surrounds to improve envelopment and gain a seamless sound field.
Regards,
