It really means nothing...there are so many variable to consider...I have a meter where I can get the same car to read 122db up to 142db in a matter of 3-4 seconds...so it really depends on what the guy with the meter is selling and what he wants to "really hit"
If it isn't at an official DB Drag Race, or other sactioned event, it ain't worth sportin'
Plus, does it really matter how loud it is? (I know, there are boomers out there somewhere sayin' loud is ALL that matters...not here to debate that, it's your system...)
If you like the sound of your subs, that's all that matters. My very first system had Pyramid subs, and I qualified for the IASCA finals with 'em!