....in short:
Reversing your phase may pervert your stage...something like that...;)
There was onceuponatime a means of crosswiring the L & R channels that didn't seem to indicate 180ing one or the other, but was purported to 'nifty things' to the stage....and wouldn't cook ones' amp...
If anyone has a better SSD between ears in regard to this, chime in...
(I already sift enough leisure into this digital sandbox....*L*)