Hummm. Okay I have Ran the HK400d's 12volt setup on stock dodge alt with one extra battery depending on your ohm load wont pull that much still a good amount though and ran them on a 16 volt setup, good sub amps help me get into the 150's with one sub. Ran two HK1998 at 1 ohm not a 2 ohm stock alt with a extra batt ran fine never went into protect at all. Ran their ma498i four channel amp for years loved it made good power never drew alot of amps neither did the hk1998's. Ran the HC4002 tad bit over rated never drew any amount of amps reall didnt put out that much power at all. Thats about 10 years old. Run alot of their speakers. Line drivers good bass drivers too 8volt plus outputs....
So I say Ma Audio.