I ran a pair of 10” DCON’s on an Arc XDi2000 at one ohm, 2.5x their rated power in a bad sealed enclosure. Never hurt them thermally but did cause a little trouble mechanically. The prefab sealed enclosure started to come apart.
I honestly feel that if the enclosure hadn’t started to leak they would probably have been just fine. Like I said I never hurt them thermally, the coils still look like new.
As a result I started designing a ported enclosure around using them on my SAZ-2000 in my Grand Prix. According to the modeling, with 25hz tuning and an enclosure slightly larger than the maximum recommended size they should handle the power mechanically. By manipulating the enclosure size and tuning I managed to put the drivers’ peak impedance right where the xmax peaks allowing them to not exceed their rated xmax even on 2.5x rated power.
Of course it’s all theory and modeling so real world results are going to vary to a point but I plan on trying it out at least. My point is that if everything is good with the voltage, clipping, distortion, etc. I wouldn’t be nearly as worried about thermal damage especially if you’re talking a single 8k on the two subs, you’re only 500 watts over with the ratings and that’s never going to even be noticeable.