How the gap of strings to PU affect the guitar sound?

Someone say "pickup height change the tone", really? The gap of strings to pickup distance affect to the sound of guitar? I set the gap = 1mm, 2mm, 3,, and 5mm then record every time. Checked the level and compared the sound. Guitar: Gibson Les paul Custom Neck pickup: Seymour Duncan SH-1 Bridge pickup: Bare knuckle Juggernaut 0:00 Volume difference (neck PU) 0:51 Volume difference (neck PU) 1:42 Sound difference(Neck PU) 4:04 Sound comparison(Neck PU) 5:32 Sound difference(Bridge PU) 7:49 Sound comparison(Bridge PU) #guitar #pickup