4 speaker outputs.... 6 speakers???

[soilsample]

Hello all,
I'm getting ready to buy and install an Alpine CDA-9857.

I've got new infinity tweeters and 5 1/4" 2-ways in the doors. I plan to buy some new 6X9s for the rear.
I'd like to push these 6 speakers from the head unit. My door speakers are not true components, so there's no crossover.

Can I just run the 5 1/4 and the tweeter for each door off of one speaker output? or will that change the Ohm load on the amp in such a way that I'll fry something?

I'm planning on Only amping my sub at this time due to the fact that I'm currently amping my front speakers and picking up too much RF noise due the the amp on top of the battery (MCS),,, which causes some annoying whine. (which isn't showing up in the sub)

Thanks for any advice,
Donald

[GBMINI]

There *is* a crossover for your new Infinitys; it's just built in to the speaker and not a separate box. Probably only a little capacitor.
No problem running them from the factory HU - the capacitor filter means you're not actually driving two 4 ohm speakers from one output. The factory speakers are just the same (look carefully at the tweeter in the top of the door and you'll see a capacitor filter attached to it).

[soilsample]

Thanks Ian,
You've confirmed what I was hoping.
My tweeters do have a capacitor type crossover inline...... once again your knowledge and helpfulness is appreciated.

Thanks
Donald