Car Audio

Hey guys. Dunno if anyone here know something about car audio but I might as well give it a shot.
In my car I have this amp. Kenwood kac-742.
Now I have 4 speakers that I want to hook up to the amp. The speakers have the same impedance which is 4ohms.
My dad says that it is ok the put the speakers 2 by 2 in serie.
But I will get an impedance of 8ohms then.
Dunno I dunno if thats goos for the amp or the speakers..
Any suggestions?
Thnx in advance,
Nin.
Answer #1
The Kenwood KAC-742 amplifier has four speaker outputs. (right & left FRONT) & (right & left BACK)
Rated Power Output = 2 ohm per channel which means using 4 ohm speakers will be fine.

FYI > An amplifier will be rated for a maximum load per channel which is specified in ohms.
Wiring speakers in series will double the rated ohms of the speakers load. (2 x 4ohm) = 8ohm
Wiring speakers in parallel will halve the rated ohm of the speakers load. (2 x 4ohm) = 2ohm
Answer #2
The four speakers will all come in the back. So the amp only gets the rear input atm. The standard front speakers will just be powered by the radio itself, not by the amp.
At present they are in wired in series and plugged to the amp like this:

Answer #3
It doesn’t matter where you physically locate the speakers… you still connect four speakers in the same manner.
By connecting the four speakers as shown in my diagram, the only thing effected will be the way in which your fader and balance controls work.
Since they are all in the back; I would imagine you will set them (controls) all in the “middle” anyways… no reason to do otherwise.
Answer #4
Yeah but in your diagram the amp gets the front and the rear input. And isn’t my front input used for my standard speakers then?
Answer #5
If you are coming directly from your head unit (radio) to the amp, then you will have to split the radio’s left/right rear output connections.
If you had an EQ in line between the head unit and amp; the outputs would be provided for you from the EQ without the need for splitters.
Note: You can’t connect the radio’s powered outputs into a power amp; if the radio does not have a low-level outputs, you will need converters.


One really needs to know your complete system in order to see what exactly it is you are trying to accomplish.
It’s tough to guide you from just a single component or two because, like a computer, it all has to be compatible.
Answer #6
Ok. So ur saying that I need to split the 2 rear output wires into 4 and connect it to the amp that way? (Just making clear that I understand it )
Dunno if it’s good for anything but the radio is a sony MEX-BT3700U
And these are the connections it has.

Answer #7
In answer to your question… yes you do understand correctly.
Ok… this head unit has both powered and low-level outputs.
The power comes from the harness #3 in the diagram and has a power output of 17watts per channel @ 4ohms.
The low level outputs are, of course, from the RCA connections.
I don’t know what speakers you have or their power rating, but I would consider utilizing an additional amp if you are set on this type configuration.
Seventeen watts is not much for a the front two speakers in a six speaker system.
If money is a factor, I would suggest running a four speaker system using the components you already have.
Otherwise, follow the hook-up of my last diagram or wire the additional rear speakers in the original manner you have now; only wire them in parallel instead of series since your amplifier can carry a 2ohm load.
Either way, the rear speakers will get the same amount of power delivered to them.
Rated Power Output:
2 channel mode @ 4ohms = 80watts x 2 (40watts x 4 in parallel @ 2ohms)
4 channel mode @ 2ohms = 40watts x 4
Good luck with your project.