I am assuming that BOTH speaker systems are being wired with woofers out of phase.
First, some crossover networks, having a 180 degree phase shift between woofer and tweeter, require that the two drivers be connected with opposite electrical phase. Some other networks having 90 degree phase shift, are "wrong" (electrically) no matter what you do.
If one connection (chosen by the designer) yields flat response through the crossover frequency, then inverting one driver will cause a deep notch at the crossover frequency. (In fact this is the best way to measure the crossover frequency). Perhaps your room has a resonant peak around the X/O frequency, or, more likely, you just don't like that frequency.
First, some crossover networks, having a 180 degree phase shift between woofer and tweeter, require that the two drivers be connected with opposite electrical phase. Some other networks having 90 degree phase shift, are "wrong" (electrically) no matter what you do.
If one connection (chosen by the designer) yields flat response through the crossover frequency, then inverting one driver will cause a deep notch at the crossover frequency. (In fact this is the best way to measure the crossover frequency). Perhaps your room has a resonant peak around the X/O frequency, or, more likely, you just don't like that frequency.