Sorry for sounding like an idiot but I have read alot about speaker placement and how to set up 3 way components and they always talk about PLD's. Was wondering what that stands for. Thanks
PLD = Path Length Difference The path length they're talking about here is the distance from the speaker to your ear. The difference is between the left and right sides of the car (i.e. left mid, right mid.)
You'll commonly see "minimize PLDs". This is important for keeping good phase.
If your HU has time alignment and you go active on it it'll help with PLD. Having TA or good PLD can make a world of difference in how the system sounds.