Need input wiring amp/speaker/sub

[adamwsmith1980]

Hey Guys,

I have a couple questions on install. It has been since high school (16 yrs) since I've done any audio upgrades and i need some help. Here is my current equipment.

1. Precision Power Amp 900.5 5 channel amp

RMS output 70x4 & 270x1 @ 4ohm

RMS output 115x4 & 440x1 @2ohm

2. Polk Audio 6.5 component speaker. I bought two for the front doors. Still deciding if im going to replace rear speakers. Speakers are 100RMS 4ohm

3. Infinity Kappa 100.9 Sub

RMS 350 with a switch to select 2 or 4 ohm

Questions:

1. If i connect the positive and negative from one speaker to one of the channels on the amp, is the speaker now running at 4ohm? There is no switch to run the amp at 2 or 4 ohms, and the instruction manual doesn't say anything about The amp has a switch to run ST (Stereo) or 4ch. The manual states: "ST allows the front, rear, and subwoofer channels to receive signal from only the front RCA inputs and 4CH allows for independant front and rear RCA inputs and the subwoofer signal is taken from the rear channel input." I am assuming ST will limit my ability to fade front and rear? I have 3 sets of RCA cables so i have no problem just running for front, rear and sub, just wasn't sure exactly the difference.

Is 70W at 4ohm going to be enough for these 100w Polk speakers?

2. If i wanted to run the sub at 2 ohm, how would i wire it? The sub is rated at 350 RMS, and my amp is rated 440 at 2 ohm, and 270 at 4 ohm. Would you recommend 2 or 4ohm? If i run at 2ohm i obviously need to turn the gains down.

Any other thoughts you have on how you would run this system feel free to share. I will eventually replace the rear speakers probably with another set of 6.5 components and use the 6x9 conversion piece that has the 6.5 opening and a spot to mount the tweeter. Im not too worried in the rear to have optimal tweeter placement. I may even just put in a two way speaker and not do a component. Not sure on that yet.

Thanks for your help!

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[adamwsmith1980]

Well after a bunch of research i think i figured my main question out. The speaker determines how many watts the amp feeds it, and how you wire speakers together determines their impedence and thus determines how many watts the amp feeds it. Someone tell me if im wrong.

 

[LongThrow]

Is your sub dvc or svc? If its just a svc and uses a switch for the impendance to be seen as 2 or 4, then just wire normal pos sub to pos amp and vice versa. If your amp is really rated at 440 at 2 ohms then run the sub at 2 ohms using your 'switch'. Youll have maybe a few watts for headroom. Adjust your gains as such. 70w will push your speakers 70% of its capabilities if theyre 100w. But they should suffice.