My setup. 4.0. Phantom center. 4 small tower speakers set to large. No sub. I live in apt with thin walls. Front towers are 8 ft from main seat. Surround towers are 4 ft from seat. I use 5-channel mode a lot for listening to music. If I want all the woofers as in-phase as possible. Will setting different delays distances from front to back speakers affect that versus setting them all to "0 ft". I assume delay affects phase. I suppose u can test this with bass test times and spl meter.