Infinity Reference 611a, over achiever?

[Turbocharged]

So I've had my Infinity Reference series 611a for a couple years now, pushing a Kicker L7 12" wired to 2ohms. Recently I had a JL W7 10" fall into my lap ($40, pretty much free for that sub), and for shits and giggles I wired it in as well in parallel, which by my math should put the circuit impedance at 1.2ohms. The amp is not listed as 1 ohm stable, and I expected it to go into protect mode, heat up, blow a fuse, something. But now I've been running it this way for a week, and it seems to be handling it flawlessly. Gets a little warm, but nowhere near warm enough to cause concern.
So now I'm wondering what the deal is. Are these amps overbuilt? Is mine special? Is 1.2ohms just barely enough to keep it from shutting down?
And before someone goes into lecture-mode about how "you shouldn't run it outside the parameters stated in the manual", stuff it. You'll never learn anything new if you don't push the limits.

[chithead]

Actually, I'm curious how you have it wired, because the W7 10" should be a single voice coil at 3.2-3.3 ohms.

Would be just fine for that amp though, are you running ported or sealed?

[chad]

What is the impedance RESPONSE in the pass-band you are using it in???

[Turbocharged]

Chithead, I was assuming the JL was exactly 3 as the specs say. I'll stick the multimeter to it a little later.
Sealed boxes.

Chad, I know a decent amount about this stuff, but I don't understand your question. Do you mind explaining further?


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[chad]

Like a frequency response a driver has an impedance response, and it changes in the enclosure... It is far from resistive and a DMM won't tell you what it is by reading the DCR.

Example, my Dayton sub has a rated nominal impedance of 4 ohms. However, in the passband I use it, it never falls below about 6 ohms.

[Turbocharged]

Put the multimeter to it, and got some strange readings. Read 2ohms through the whole circuit, and 5ohms through just the L7. This concerns me. I should be seeing 2 through the L7, can't figure out why I'm getting 5. First guess is that I lost a voice coil. That still doesn't account for the other 1ohm, but it comes close to making sense. Thing is, I haven't noticed any drop in performance. Still works like new, which is contrary to the dead coil theory. Gonna have to investigate further...
This is leading places I did not anticipate.

[chad]

you are reading the resistance of the coil, you are not seeing the impedance.

Oddly, the DCR should be lower than the impedance.