Speaker Polarity - stock wiring harness which is + / -
 

Guys,
I have a quick question. I removed my stock door subs and I'm installing new JL subs. I have a question on the wiring polarity. The connector has a solid black wire and a black wire with green srtipe. Which one is + and which one is negative? The black with green stripe wire has a slightly larger connector so I wanted to assume that's the +.

Any insight is a help.

-Steve

You are correct. A digital multimeter will tell you for sure. Connect it to the 2 leads. If the display reads (-) then you need to reverse the leads for the proper polarity.

Thanks - I'll try the digital volt ohm meter. What's odd is that the new speaker played no matter haw I connected it... That didn't make sense.

I'm thniking of hooking up the speaker to the stock harness and also a bypass line so when I add an amp (next few weeks) I don't have to take the doors off again...

Thanks again

-Steve

Figured it out - Thanks!!!
 

Ok, so I connected the old speaker turned it on and checked the polarity with the Digital Ohm Meter and the solid black wire was + and the black / green wire was -

So
Brown from head unit->>Black at the speaker = positive
Green from head unit->>Black / Green at the speaker = negative

Cool trick!

Thanks,
-Steve

Not odd at all. It'll play for sure, but it's out of phase.

I'm not sure how this is working. What setting and scale on the multimeter? Stereo on or off? Volume up or turned down?

Every time this comes up in a car forum I wonder just how audible it (meaning ONE side wired out of phase) would be in a car environment. It is painfully obvious on any good home 2 channel audio system, but a moving top-down car?

Getting back to Chitowndad, if you are having trouble with the VOM it seems to me that as long as both sides are wired the same (meaning black w/ green stripe to the same terminal) it would be okay and better than having one side different. Especially if you are going to replace the amp soon I wouldn't worry too much. I would just wire them up and listen to it before re-assembling the door. If it sounds okay run with it.

If I am wrong feel free to correct me, I come here to learn too!

Well the convention is to mark the positive (+) wire in some way - a contrasting colored stripe, a ridge in the insulation, even sometimes a different colored wire, say yellow(gold) vs white(silver). But this convention is not always followed.

@JackG, You can use a DMM to test AC voltage output at the amp speaker terminals, or speaker lead wire. The reading (signal present - Amp ON) will be a positive number if the test leads are on like polarity, or it will read a negative number if you have positive lead on a negative terminal.

Thanks again
 

Thanks again guys - I'm going with what my VOM says is positive (solid black wire) even though I was thinking that wire was negative because it had a smaller connector and I was also under the same impression that + is marked with a stripe.

Thanks again. I'm heading down the right path...

-Steve

LB, I have to apologize. I set you up a bit. In real life, I'm an EE (Electronic Engineer), and I was having a bit of trouble reconciling your "test".

You see, AC voltage (Alternating Current) has no polarity. A DMM on the AC scale will not show a + or -, as there is no polarity to indicate. It will simply indicate the AC voltage.

A DMM on the DC voltage scale *will* show polarity. If you measure a 9V battery, and the leads are plus to plus and minus to minus, the meter will indicate + 9V. If you swap the leads, it will indicate -9V.

The problem with your test is that an audio signal is AC. Voltage drives the speaker in an AC format, pushing and pulling the speaker cone in and out, producing the pressure waves our ears interpret as sound. In fact, you can connect a battery (a DC voltage) to a speaker's terminals and it will drive the speaker cone either out, or in. Reverse the battery, and the speaker cone will reverse it's travel. The AC voltage representation of sound moves the speaker cone in and out, making the sound waves we hear as music.

Speaker polarity simply makes sure that when the signal is "positive", all of the speaker cones move out. If some of the speakers are out of phase, then some move out and some move in (out of phase) and they cancel each other. If you connect *all* of the speakers out of phase, then the music will still be OK. What's important is that all of the speakers are connected in the same phase, with all of them moving in or out at the same time.

The bottom line is that your test isn't valid. While you may be able to measure some DC +/- component on some types of audio amplifiers, not all amps will be the same. If you connect a DMM set on the DC scale to an audio amp output, it will try to figure out if the signal is mostly positive or negative. That results will totally depend on what sound is playing at the moment you make the measurement. If it were a pure tone sine wave playing, the DC voltage would be 0, as the plus and minus voltages would be identical.

Without factory documentation or some sort of marking on the original speakers as to their polarity, the final test is going to have to be your ears. If the speakers are out of phase, you'll notice a lack of bass and a fuzzy stereo image. Flipping the wires +/- while listening to the same music at the same level will tell the tale.

Thanks Jack but now I'm more confused
 

Wow, now I'm more confused... Jack - what do you recommend that I do next??

I just posted this question about the front speakers but I found the wiring diagram for a 2001 Boxster with the M490 option and jotted this down:

Right door speaker: + Green
- Green/Brown

Left door speaker: + Green
- Green/Brown


Front left dash speaker: + Yellow
- Yellow/Brown

Front right dash speaker: + Red
- Red/Brown

Sounds like your colors are diff but if the above is any indicator the negative is the wire with the contrasting stripe.

You want the absolute phase of the new speakers to be the same as the old speakers... in other words, when the old speaker cone moved out, you want the new ones to move out as well.

Take a 9V battery, and touch it momentarily across the old speaker terminals. When you do this, observe which way the speaker cone moves... in or out.

Then do the same to the new speakers. Making note of which terminal (+ or -) you touched to the large lug on the old speaker compared to the new one, you'll now know which lug on the old one, and which color wire, is the same as the positive terminal on your new speaker.

If plus to the large lug on the old speaker makes the cone move out, and plus to the plus terminal makes the new speaker cone move out, then the large lug and wire should be hooked to the plus terminal on the new speaker. Make sense?

Be careful to only *briefly* touch the battery to the speaker terminal. While 9V isn't much power to a speaker, a speaker is designed to handle AC current. A battery is DC, and DC will kill a speaker. A quick touch (1/2 a second) will show you the movement, and won't hurt anything. If you're worried, start with a single C or D cell. They are only 1-1/2 volts, but may not give you enough movement to see.

As someone pointed out, even if you end up getting them backwards, you may not be able to hear the difference in a roadster anyway. Wire them both the same, and enjoy! It won't hurt anything if you get them wrong, except the sound if you're a critical listener.

I appreciate your correction. My info was taken from an article I read about stereo installs which I accepted at face value. With you being a double E, I don't have the background to dispute what you say. I never have an issue with someone pointing out my information is, or may be, incorrect. I believe that's part of how you learn.

But, what's with the setup you admit to? Why do you feel a need to do that? I guess I don't see where that's very helpful at all. If you know someone's info is incorrect, why don't you just say so?

It wasn't intentional. I didn't understand your test, and my initial questions were so I could try to figure out what the test was, and how it might work. I'm the first to admit I don't know everything, so I was curious.

It was only after that I thought my first post might come across as being a setup, so that's why I said that it might be a bit, and apologized for it. Nothing personal at all.

There could possibly be a way to use a DMM to figure out which amplifier leads is positive by measuring a signal, but I can't imagine a way for that to work. Certain amplifier designs have the negative lead going to ground, and that could be measured using the resistance scale of a DMM, but that doesn't work for all amps, and that's not the test you mentioned.

If you can remember where you read about it, please let me know. I'm genuinely interested in how they're doing this.

OK, Fair Enough. Maybe just late-night overreaction on my part.

Were it me, I'd have probably edited my 1st post, or deleted it and reposted the pertinent bits. I'm a believer in following the Confucian saying: "It's OK to call someone a Fool, just don't prove it" :)

I'll see if I can locate that article for you. Not to prove or disprove anything, but so you can evaluate it yourself. :cheers:

figured it out!!!
 

Ok so I did the battery test and I figured it out. The wire with the stripe is the positive (Black with green stripe) and the solid black wire is negative!

Thanks for all of the tips, I appreciate the help!

-Steve