Got a pair of 6.5 subs to replace the lower speakers in the passenger doors. After taking them out of the box they appear to be dual voice coil with 2 sets of leads/ connections. How the heck do I wire these? Want to be careful since I think these are already wired in series with the truck door woofers

 

The box that the woofers came in should specify how many ohms are each voice coil then ohms law is used to get it to a 4 ohm load if it is the factory amp but if you are wiring a aftermarket amplifier then see what are is the minimum load the amp can take. Most high end aftermarket amps ex. Alpine, Rockford Fosgate, Kicker can handle a 1/2 ohm load but 4 ohms is the standard for car stereo.

Example using 1- 4 ohm dual voice coil woofer in series will give you a 8 ohm load, that can be done by connecting the negitive (-) terminal from your amplifier to the negitive (-) speaker terminal of the first coil, then your positive (+) terminal of the same coil will be tied to the negative (-) terminal of the second coil, and last your remaining positive (+) terminal will be the other lead going to your amplifier (+) speaker terminal.

Now using 2- dual voice coil woofers set up for 8 ohm can now be wired to each other in parallel will give you a 4 ohm load, to do this you will first need to wire the 2 woofers identical as stated above then connect the negitive (-) speaker terminal of the first coil to the other woofers negitive (-) speaker terminal of the first coil (parallel), do the same for the positive (+) speaker terminal of the second coil to the other woofers positive (+) speaker terminal of the second coil (parallel), now you have 2- 8 ohm speakers in parallel then in series that now gives you a 4 ohm load.


Image above shows 2 ohm voice coil woofers in series parallel. 2- 4 ohm loads = 2 ohms
Using 4 ohm voice coil woofers in series parallel. 2- 8 ohm loads = 4 ohms.
Use same wiring diagram showed above just use appropriate voice coil resistance that your amp can handle.

 

Wow thanks. So as far as a drop in replacement I kinda blew it. Planned to run these with stock amp and head unit.

 

So can anyone chime in on running this in the 2ohm configuration with the stock amp?

 

You'll blow it up for sure.
The odds of a stock amp being able to run at 2 ohm is slim to none and not worth the risk IMO.
Run the voice coils in series for 8 ohm and never worry..........

General speaking I think stock sound systems are designed for efficiency so its probably designed for 8 ohms already.
This thread might help - https://landroverforums.com/forum/di...mplifier-7662/

 

If you buy 2 single 8 ohm voice coil woofers you can wire them in parallel that will give you 4 ohms. The factory amp can only handle 4 ohms minimum or you will fry the factory amp and if you buy 2 single 4 ohm voice coil woofers and put it in series you will have 8 ohms the problem with that is you will get less output from the factory amp best to keep it at 4 ohms. Car stereo usually 4 ohms, good car audio amps can do 2 ohms, expensive car audio amps can do 1/2 ohms, and all house audio systems run 8 ohms as where Bose runs 6 ohms. Don't complicate it keep it at 4 ohms - Good luck.

 

 

I measured the resistance of each Philips OEM sub, 2 ohms each speaker. They are wired separately back to the amp. Not sure if there is a difference in audio amplifiers based on model.

 

Rear door subs are different than the door mids. They should be 4 ohm. You could get a resistor and put it in series with the speaker to make it effectively 4 ohms. If your speakers are 2, get a 2 ohm resistor.

 

That is good so all that needs to be done is to wire them in series it will be a 4 ohm load at that point so no resistor is needed.