Metra Speaker Harness Polarity

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Jebiruph

Jebiruph

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Hoping that I can tag onto this. I am planning to replace all of the speakers in all the locations in my JT Gladiator, which are identical to a 4 dr JL Wrangler.

Are people saying that _both_ the 72-7902 and the 72-6514 flip the polarity? If so the speakers should all stay in phase, and it's usually not a big deal if the phase of all of the speakers together are flipped as long as they are _all_ flipped, together.

Thanks!
They both flip and you are right, changing them all keeps them in phase.





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kd1yt

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Speaker crossover electrolytic caps are what are called nonpolarized or bipolar- the audio signal is alternating current and so they don't have a steady +/- . Using a standard (non-nonpolar) cap in a crossover application is a recipe for problems, and capacitor failure (and sometimes speaker failure because then the bass is no longer blocked from speakers not meant to handle a lot of bass). Phasing may matter with some source material, but try some time with a home stereo, one pair of speakers, switching the phase (making sure you keep both speakers in phase with each other). You may hear nearly nothing you can detect and a lot of audio equipment isn't even that meticulous about maintaining absolute phase. Low bass may matter more than higher frequencies, which is why subwoofer amps often do have switches or knobs for phasing.

Having speakers out of phase with each other within a system is a problem, although with some crossovers you actually _need_ to invert phasing of some of the drivers because some crossovers (usually only more complex ones, not just a series cap) actually introduce their own phase shifts.
 

robd1438

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Front left dash for me had gray/yellow as positive; seems to be different for different folks. I used volt meter to quadruple check.
 

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Thanks. What's odd about those diagrams is the actual wire colors for the roll bar speakers in my 2020 JL are white and grey. So, I don't know how that aligns with the color codes on the schematic. Frustrating.
Same here. So here is my problem. The metra Barnes would not fit so I clipped it and the Jl harness off and just wired them together for my infinities for the 3.5. I assumed white was positive and grey was negative. So I hooked them up that way. White to white to positive. Grey to black to positive. Now after reading this post. I think I may have reversed it.
So does anyone know for sure on sb. Is the grey wire actually positive and white negative.
 

StaindReality

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Thanks. Trial and error revealed that in my JL the white factory wires in the roll bar are positive and the grey are negative.
Sorry. This answered my question. Seems I did do it right. Didn’t notice this post the first time. I also did white to white to positive. Etc.
 

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I am electronically stupid but am replacing the 3.5” speakers soon. How do you test this stuff out to determine if the adapter wires need to be flipped?
 

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I am electronically stupid but am replacing the 3.5” speakers soon. How do you test this stuff out to determine if the adapter wires need to be flipped?
A little late on this thread but safest bet is to do the 9v battery speaker polarity test. Google that. I’ve found that what is shown as positive/negative on the wiring diagram Is not correct, as is the assumption that the capacitor side of the stock speakers being positive is not correct.
I confirmed positive for my stock speakers was the non-capacitor side and made sure to hook up my new speakers positive to the same wire that was originally connected to that terminal.
I did the test on all 4 3.5” speakers just for good measure when replacing them.
 

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A little late on this thread but safest bet is to do the 9v battery speaker polarity test. Google that. I’ve found that what is shown as positive/negative on the wiring diagram Is not correct, as is the assumption that the capacitor side of the stock speakers being positive is not correct.
I confirmed positive for my stock speakers was the non-capacitor side and made sure to hook up my new speakers positive to the same wire that was originally connected to that terminal.
I did the test on all 4 3.5” speakers just for good measure when replacing them.
right. You do that on the new speaker...but how do you know if the polarity on the harness is reversed?

i guess that is what I am asking
 

Sector281411

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I recently replaced my dash and knee speakers and the adapters for the dash from Metra were correct, as well as the adapters for the knee speakers that came with the Metra pods.
 

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right. You do that on the new speaker...but how do you know if the polarity on the harness is reversed?

i guess that is what I am asking
Before disconnecting the old speakers, I looked to see what color wire was connected to the capacitor side and what was on the other.
Then I removed the speaker and did the battery test so it told me which side was positive and which was negative.
Then I hooked the new speaker up based on my findings. My new speakers have built in crossovers with clearly marked + and -.
I’m making an assumption that the original wiring was correct to begin with and just connecting the new speaker to what was on the old stock positive terminal.
 

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Hoping that I can tag onto this. I am planning to replace all of the speakers in all the locations in my JT Gladiator, which are identical to a 4 dr JL Wrangler.

Are people saying that _both_ the 72-7902 and the 72-6514 flip the polarity? If so the speakers should all stay in phase, and it's usually not a big deal if the phase of all of the speakers together are flipped as long as they are _all_ flipped, together.

Thanks!
ANC messes that up
 

Crusifix

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This thread ended up all over the place... My ADD brain couldn't follow what the final verdict was. So we need to flip the wires on the 72-6514 and the 72-7902 harnesses?
 

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Here is a video where 5 Star is replacing the 3.5" speakers in a JT. They do some checking of polarity. The also come to the conclusion that the side with the capacitor is negative. I assume this would be the same across the JL and JT. As they say, you can look at the wire in the harness that mates up with the side with the capacitor to double check. They don't use the Metra harnesses, it looks like they splice their own wires in. They also have a video on replacing the knee speakers in a JT. Also note they do not use the capacitor that comes with the Alpine speakers.

 

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