1999 Lincoln Continental Alpine system upgrade speaker wiring help needed (2.5ohm speakers)

[aerovette99]

Hello. I have the 6 speaker Alpine system in an older Continental. I changed the stock radio to the Alpine ILX-W650. This original Alpine system has 4 door speakers and an amp that has a built in crossover driving a pair of 5x7 or 6x8 in subwoofers in the rear deck. They only provide bass. I have 2 sets of Infinity Kappa 62x (6.5") for the doors, and a pair of Infinity Kappas 93x (6 x 9) for the rear deck sitting in boxes. Trouble is, the speakers are ALL 2.5 ohm. This one is baffling. If needed, I have a 4 channel amp (Fosgate P400-4), and a 2 channel amp (fosgate P200-2). Both can be made bridgeable. At this moment, the car is stock with the ILX-W650 being the only piece that has replaced the factory Alpine head unit. I have the front and rear channel of the stereo hooked up to the 4 doors, and the rear deck speakers hooked up to the subwoofer output from the head unit (since there is an amp that is already crossed over installed from the factory). The original system sounds decent enough, but not as good as I would like. If I run the rear doors to the rear deck in series, I'll have 5 ohms with the 2 pairs of 2.5 kappas mating up with the 4 ohm stereo, so I'm not real certain what would be the best way to hook this system up. I really hate to have the 6 x 9 kappas in the deck wasted on only bass, Any thoughts would be appreciated.

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[Kickstand Premium Member]

So you have 2 sets of 6.5's and one set of 6x9's all running at 2.5 or technically 2.7 ohms
You have a P400-4 Which will do 4x100 @ 2ohms
And a P200-2 which will do 2x100 @ 2ohms
So I think your over complicating things
Just run the 4 6.5's off the 4channel, Don't bridge it. One speaker per channel will give you 2.5 ohms
And run the 6x9's off the 2 channel, same thing one to each side
Depending on the HU you might have to use a set of RCA y adapters on one of the Pre outs so you won't have to use the sub out.
I suggest splitting the front out to run the 4 channel and using the rear strait to the 2 channel

 

[aerovette99]

So you have 2 sets of 6.5's and one set of 6x9's all running at 2.5 or technically 2.7 ohms
You have a P400-4 Which will do 4x100 @ 2ohms
And a P200-2 which will do 2x100 @ 2ohms
So I think your over complicating things
Just run the 4 6.5's off the 4channel, Don't bridge it. One speaker per channel will give you 2.5 ohms
And run the 6x9's off the 2 channel, same thing one to each side
Depending on the HU you might have to use a set of RCA y adapters on one of the Pre outs so you won't have to use the sub out.
I suggest splitting the front out to run the 4 channel and using the rear strait to the 2 channel

That sounds like a great option. I really didn't want to use the 6x9's strictly as bass. Guess I'll need to pick up a 2nd #4 wiring kit for the 2nd amp.

 

[Kickstand Premium Member]

Honestly
Since your not running subs and only running 600 watts
You can just use 1 run of 4 gauge and split it at the back with a distribution block or a fuse block
You will need 3 sets of 2 channel RCA's and 2 RCA Y adapters ( 1 Female - 2 male)
I always found it easier to split them at the amp rather than try and cram them behind the HU

Edit- You would have to put a bigger fuse on your power wire as well

 

[aerovette99]

Honestly
Since your not running subs and only running 600 watts
You can just use 1 run of 4 gauge and split it at the back with a distribution block or a fuse block
You will need 3 sets of 2 channel RCA's and 2 RCA Y adapters ( 1 Female - 2 male)
I always found it easier to split them at the amp rather than try and cram them behind the HU

Edit- You would have to put a bigger fuse on your power wire as well

You are AWESOME. Thanks so much for your help.

 

[aerovette99]

Honestly
Since your not running subs and only running 600 watts
You can just use 1 run of 4 gauge and split it at the back with a distribution block or a fuse block
You will need 3 sets of 2 channel RCA's and 2 RCA Y adapters ( 1 Female - 2 male)
I always found it easier to split them at the amp rather than try and cram them behind the HU

Edit- You would have to put a bigger fuse on your power wire as well

The #4 kit that I purchased has a 60 amp fuse. Will that be enough?? I like to rock, but I'm more interested in keeping the RMS authentic via keeping the THD down to almost nil. Most of my fosgate amps (I have 4 cars with Punch amps, and 1 with 4 amps alone in my 99 C5 Corvette) have the gains set around 4 (of 10) as the meter that I use, show this is the lowest THD for the rated output for the available ohms.