Says who?

Me. Can you tell me a load in your system which is going to fluctuate
more than the amp??? The headlights are constant, your ignition coil is
pretty constant, head unit may fluctuate a few amps but not if your
running everything on preouts. The amp may fluctuate from 10 amps up to
70 amps and back again. The only other thing that will draw that much is
the starter and I don't tend to use that while I'm driving.

If you flip the AC on high to off over and over again it'll usually beat
your amp.

How can you assume whether they did or didn't help my system??? Next
time, just for you guys, I'll get before and after SPL numbers just to
see. I don't imagine it'd be worth much at full tilt, maybe .5 Db if
that on the sustained bass, and nothing for the initial hit. I did
however notice a SQ difference, and my personal taste liked it.

If you can detect half a dB in a car, then come on by so I can write up a
paper on you.