since the Hifonic is more efficent (class D) i would take that unless u have a HO alternator. type r's can handle more than what they are rated so 800 watts rms would not hurt it(the audiobahn probably puts out 780+)
Get Big, the A8000T is Class D as well, I know, I own one. I bought the amp at the suggestion of Isaac, if you've read his posts, he knows what he's talking about. He didn't suggest Hifonics to me, as he's seen them fail, and he's tested the Audiobahn he suggested to me, and it puts out 800W RMS on the letter. So I think that answers this question. Get the Audiobahn, Hifonics lacks more SQ and Audiobahn.
"(the audiobahn probably puts out 780+)" - So what exactly does the "+" mean anyways Big? The Type R's are 500W RMS aren't they? I don't believe they are SPL oriented, so why would they handle much more than that? The Type R's aren't like RE subwoofers which can sometimes handle 500W RMS more than suggested. Afterall, it's Alpine, another mass-marketed brand like so many others, so just keep that in mind.
Mike, you can't run that sub at 1 ohm on the A8000T. You may be able to on the Hifonics. However, running subs at a lower impedance, can cause distortion, whether it's audible, is still in debate. But it's known to be there. Hifonics amps are generally used to just achieve high SPL's with little $$$. Audiobahn would be more in your range for the fact it's aimed more towards the daily driver, and not reaching insane SPL's with garbagy parts.
Don't get me wrong, I'm not saying Audiobahn doesn't make their own Hifonics-type amps which provide lots of power and no SQ, but the series we're speaking of has decent SQ and provides the power it says it does.
Ohms is impedance. It is the resistance the subwoofer (in this case) puts on the amp. If you run a subwoofer or speaker to the amp at a lower impedance than it is designed to handle it will overheat. 1 ohm is no better than 2 ohms. It's just a wiring configuration to determine resistance. Hifonics amps may be able to do 800W RMS at 1 ohm, but at 2 ohms, it can't do that. Audiobahn's can do it at 2 ohms, but can't safely run at 1 ohm. So really, it doesn't matter.
A type R should be able to handle 800 rms. I'm running my swr-1222D at 700 and it's fine, and my friend ran his 2 swr-1221D's at 800 rms each for quite a while until I bought them off him, and those were only 300W rms. and they were still perfect.