2 ohms bridged is fine for the 8604, not 1 ohm bridged though.
I run mine at 4 ohms stereo. I won't go 2 ohms stereo. I'm picky like that. Don't think these cheap amps are engineered to handle loads under 4 ohms stereo as well as lets say an Audison amp.
Yes you correct. The Kenwood XR401-4 Hi Res amps sound good and are strong. I am now in posses of removing the Polk MM's and installing the new top of line Pioneer TS-Z65CH 6.5 Hi Res component speakers in all 4 corners. I am installing a Hi Res system. I already earlier this year installed my new Pioneer HU that plays high quality Wave and FLAK files though USB port. After watching BigD do that amp test with the Kenwood mini amps wow. I don't hear much about the Kenwood amps but i think they are sleepers and good for the money. So when BigD did the amp test i was like see told you so. I had no doubt that these Kenwood XR-401-4 would also be strong. There class D and much smaller and less heat then my old amps. There installed in a Tacoma XCAB truck so i have 2 of them. One to my 4 corner mid / high and then one bridged to my 2 8" Polk subs. All i have to finish is my rear installs now. I had some old school Kicker Substations tubes in 6" and 8" (remember those back in the day) So when i installed all Polk MM's i also changed out the old Kicker subs in the tubes to Polk. Love these old school Kicker substation tube boxes. They were very popular back in the day. I feel that if someone was to reproduce them again today they would be great seller. They fit perfect in the Xcab section. And they are flat on bottom so not to roll around. The 8" Polk subs they fit perfect in the tubes and sound good but I decided to keep the Polk subs but change out to the Hi Res Pioneer speakers. I am not so much looking for LOUD but for SQ that is why i went to Hi Res system. In a daily driver vehicle i think LOUD would get old real quick. Plus i'm not in my 20's anymore. That's just what i wanted, your mileage may very
