Audio Experts

[Meir]

Hi Giller.
Just like you said. If you connect the speakers in parallel, resistance will be 2 ohms. If you will connect them In line, it will be 8.
Just to make sure we are on the same page, full shortcut, is 0 ohms.
So the lower the number is, the resistance is higher.
If you go with 8ohms configuration per side, your unit will have less load, but you will experience decrease in volume.
At the 2 ohms configuration, you will get more volume, but the unit will work harder (after all, more resistance on the output).
The question is, what is the unit specifications, and can it hold the loade?
As far as I know, there is no head unit that can handle 2 ohms.
You will just burn the outputs.
If you are using an amp, it depends on the amp specs.
Today, most amps can handle 2 ohms with no issue.
Subwoofer amplifiers (mono) can get down to one ohm easy. So is most modern 4&5 channels amps.
So to answer your question is, go with in-line configuration.
You are going to loose some volume, but you will not blow up the unit (unless specs specefi 2 Homs operation is no problem).

[Giller]

Perfect, thanks Meir. Sounds like I do want to go series - more ohms = less power draw on head unit. Might add an amp at some point, but right now everything is coming from the main deck, and it's at 4ohms, so need to stay above that. Great!

[SilverSSS]

you'll get 1/2 the power out of each leg that would otherwise be available out of that leg/channel if it were driving 4 ohms. If you found 2 2ohm speakers and wired them in Series then you would get full/max power out of each leg/channel. Head unit can't drive 2 ohms, amp chips will get hot and go into protect probably, but try enough times, and they will smoke.

[dghii]

Originally Posted by SilverSSS

you'll get 1/2 the power out of each leg that would otherwise be available out of that leg/channel if it were driving 4 ohms. If you found 2 2ohm speakers and wired them in Series then you would get full/max power out of each leg/channel. Head unit can't drive 2 ohms, amp chips will get hot and go into protect probably, but try enough times, and they will smoke.

Agree, except it sounds like OP is talking small rear speakers, which are not going to be hard to drive, regardless of how they're wired.

I just did this...replaced the 4 rear speakers that had rotted with new aftermarket. Nothing fancy and I wired them like the factory. I'd have to look to see what impedance speakers I bought. 3" speakers are not going to be loud either way!

[newBgeek]

You really can't wire speakers in series without it sounding like crap. The reason is that speakers don't have a simple resistance. They have an impedance which means that the resistance changes based on the frequency. This is because each speaker's windings are basically coils. Coils can be used to filter out high frequencies for subs.

If you want to keep your full spectrum of frequencies, you will have to wire each speaker pair in parallel. Then on one side of each speaker pair, you could add a 2 ohm resistor. Make sure the resistor can handle at least 1/4 of the amps output power, or pick up a speaker rheostat from Radio Shack and adjust it to 2 ohms.

Personally, I would try it without and just lower the output to the rears with your fader control. The worst that can happen is you burn out a fuse in the head unit, or start a fire and burn down your car

[alm001]

Originally Posted by Meir

Hi Giller.
Just like you said. If you connect the speakers in parallel, resistance will be 2 ohms. If you will connect them In line, it will be 8.
Just to make sure we are on the same page, full shortcut, is 0 ohms.
So the lower the number is, the resistance is lower
If you go with 8ohms configuration per side, your unit will have more load, but you will experience decrease in volume.
At the 2 ohms configuration, you will get more volume, but the unit will work harder (after all, less resistance on the output).
The question is, what is the unit specifications, and can it hold the loade?
As far as I know, there is no head unit that can handle 2 ohms.
You will just burn the outputs.
If you are using an amp, it depends on the amp specs.
Today, most amps can handle 2 ohms with no issue.
Subwoofer amplifiers (mono) can get down to one ohm easy. So is most modern 4&5 channels amps.
So to answer your question is, go with in-line configuration.
You are going to loose some volume, but you will not blow up the unit (unless specs specefi 2 Homs operation is no problem).

Overall correct, just mixed up a bit. Lower resistance means more current.