Friend thinks his system is louder than mine.....help

[thehardknoxlife 10+ year member]

Well lets just my friend thinks his system is louder than my system. Is that possible?
-His set up-

-2006 Chevy tahoe

-4 15" Mach 5 SPL subs

-4 AQ 2200 amps

-box is 5.4cu.ft ported to 32hz

My set up

2004 ford explore

4 18" DC LV5

2 Rf 4000.1bd amps

5.2cu.ft box ported to 36hz

What?.....you can't even lie right.