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I supported Toymods
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CAR AUDIO: Determining +/- on oem speakers/wiring
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Mon, 08 March 2004 02:51
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Hey all!
This is not for a Toyota, for a Nissan. Is there someway of possibly using a multimetre to determine positive and negative on the wiring? Stupid oem wiring never make sense 
Thanks guys 'n gals !
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Location:
Sydney
Registered:
October 2003
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I supported Toymods
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Central Coast
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May 2002
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Re: CAR AUDIO: Determining +/- on oem speakers/wiring
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Mon, 08 March 2004 03:17
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Can you tell if there is no + or - on the speaker connections? Typical oem plug :/
So there's not too much point trying to figure out which is +ve and which is -ve?
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Location:
Melbourne
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October 2003
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Location:
Sydney
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October 2003
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Location:
Melbourne
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October 2003
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Location:
Bundaberg, Qld.
Registered:
May 2002
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Re: CAR AUDIO: Determining +/- on oem speakers/wiring
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Mon, 08 March 2004 03:46
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 there is an easy way out of it working from the wires at the HU. wire in your speakers to the left, right, front, rear etc. to the HU.
then useing your balance control check the speakers (on the front channel), move the balance from the center to one side (doesnt matter if it be left or right). if you have more bass from the left or the right speaker than when the balance is in the center, your speakers are out of phase. to correct this you only need to change the + and - around on one of the speakers wires at the HU. then it should sound more bass with the balance in the middle that on either side, which means they are now in phase.
do that again with the rear channel to see if they are right.
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Toymods Social Secretary
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Re: CAR AUDIO: Determining +/- on oem speakers/wiring
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Mon, 08 March 2004 04:24
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| Quote: |
re: AC/DC
if speakers were running of alternating current you would have to send the earth back to the head unit/amp - but you can in fact earth it to the body. hence its all DC.
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DO NOT EARTH A SPEAKER'S (-) TERMINAL TO THE CHASSIS OF THE CAR!!!!!!!! It may work, but it is VERY BAD for both the speaker and the headunit. I do not know where you got this information but i suggest that you take it and throw it into the COMPLETE BULLSHIT pile.
Here is the method of finding out the correct phase of your speakers:
- Take one battery of any type (i like 9V)
- Find the pair of wires for the speaker in question and briefly touch the speaker's wires to the battery. Take note of which direction the speaker moves when it "pops"
- If the speaker moves OUT, you have the correct phase (wire touching + on battery is the + wire for the speaker). If the speaker moves IN when it pops, you have a reversed phase.
- That is all.
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I supported Toymods
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Re: CAR AUDIO: Determining +/- on oem speakers/wiring
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Mon, 08 March 2004 04:36
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Ahh yes, thanks Witzl ! I had been told that before, but I'm just dumb and always forget stuff :/
hehe, its actually running thru 2 little Clarion amps (stock) bolted to the bottom of the parcel shelf... But what I might do, is get the orig. speakers, and do the battery thing, then, I can see which is +ve and -ve from the gay plugs they use!
THANKS DUDE!!
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Location:
Sydney
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October 2003
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Re: CAR AUDIO: Determining +/- on oem speakers/wiring
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Mon, 08 March 2004 05:04
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if you take the -ve and wire it to the car body, does your tacho bounce with the music? 
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Location:
Bundaberg, Qld.
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May 2002
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Re: CAR AUDIO: Determining +/- on oem speakers/wiring
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Mon, 08 March 2004 07:54
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well yes there certainly is that way you described Karl.
but not everyone is keen on getting thier speaker grills off to look at the cone..
earthing a speaker wire on equipment now days is more than likely to blow the output chip on your HU. some of the older factory gear and some cheap arse bodgy HU still use the speaker earth method though.
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Brisbane
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June 2003
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Toymods Social Secretary
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Re: CAR AUDIO: Determining +/- on oem speakers/wiring
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Mon, 08 March 2004 09:17
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Thank you Mr Moderator
Please remember the Tech forum rules when answering a question people, mainly:
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BEFORE POSTING a new thread, please use the Search function to look for any existing material that may already exist in the Forum back catalogue. Use of Google is also encouraged to get an idea of basic concepts BEFORE asking more specific questions.
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AND ESPECIALLY!!!
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PLEASE do not simply regurgitate what you've overheard or read somewhere else, and call it your 'expert' contribution to a thread. Posts like this simply propagate misinformation. If you think you can refer someone to relevant web resources, by all means do so, but please do not make an independent 'statement of fact' about an issue unless you can substantiate it.
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Lost in the K hole
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May 2002
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Re: CAR AUDIO: Determining +/- on oem speakers/wiring
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Mon, 08 March 2004 09:23
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no wakka's karl 
sorry to those above i edited... just that some of the info there could get people into some serious trouble with their audio equipment....
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Re: CAR AUDIO: Determining +/- on oem speakers/wiring
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Mon, 08 March 2004 10:58
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I still dont agree that speakers run on DC current. A low level signal into an amp runs on DC at about 2-2.5v, but speakers run on AC.
A speaker works by having AC current going into the coil. On the +ve side the coil moves out, on the -ve side the coil moves in, hence the speaker moves in and out and makes sound
Why do you think that when you wire up a sub, if you have it face backwards in the boot of your car you have to wire it 'out of phase'? This means that when all the other speakers move out, it moves in - because its backwards physically in the boot!
Link from howstuff works...
Essentially, the amplifier is constantly switching the electrical signal, fluctuating between a positive charge and a negative charge on the red wire. Since electrons always flow in the same direction between positively charged particles and negatively charged particles, the current going through the speaker moves one way and then reverses and flows the other way. This alternating current causes the polar orientation of the electromagnet to reverse itself many times a second.
So how does this fluctuation make the speaker coil move back and forth? The electromagnet is positioned in a constant magnetic field created by a permanent magnet. These two magnets -- the electromagnet and the permanent magnet -- interact with each other as any two magnets do. The positive end of the electromagnet is attracted to the negative pole of the permanent magnetic field, and the negative pole of the electromagnet is repelled by the permanent magnet's negative pole. When the electromagnet's polar orientation switches, so does the direction of repulsion and attraction. In this way, the alternating current constantly reverses the magnetic forces between the voice coil and the permanent magnet. This pushes the coil back and forth rapidly, like a piston.
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Lost in the K hole
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Brisbane
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Re: CAR AUDIO: Determining +/- on oem speakers/wiring
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Mon, 08 March 2004 11:50
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that has absolutely no relevance to the current question. (not you ed)
Look at anything off a 240v signal..they have no + or -. It is a/c. hence it has no + and -,
- A/C stands for "alternating current" i.e it flows back and forth through both terminals.
- D/c flows in through one terminal and out the other...just like a speaker works.
Having a speaker in a boot firing in any direction has no relevance to its polarity or setup. you can wire up any speaker in any way to suit how you like the sound.
Wiring a speaker out of phase doesnt damage the speaker in any way either. A speakers maximum excursion characteristics, are the max it can go forward without slapping the voice coil, and the maximum it can move backwards without smashing the voice coil on the magnet. E.g i have a 15" 2000w speaker. Its max excursion is around 2" or 50mm.
This means, the speaker moves 1" out, and 1" in. overall movement being 2".
All wiring the speaker out of phase does is time delay. I.e wiring it out of phase will give a delay on the speaker wired so. A lot of good quality speakers in boxes, with 2 way horns/ speakers. have the hf driver wired out of phase, because coupled to its horn flare, its magnet sits a lot further back then the speakers'. Hence you need to put a delay on the horn to make the sound co-herent...wire it out of phase is the answer.
[Updated on: Mon, 08 March 2004 11:53]
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Toymods Social Secretary
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Re: CAR AUDIO: Determining +/- on oem speakers/wiring
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Mon, 08 March 2004 12:34
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even so, power going to speakers from an amplifier is DC.
read any amplifier specs, see what the output voltage or anything is.
Look at a speakers efficiency ratings - itll say @1w,1m. or @ 2.83v dc
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Location:
Bundaberg, Qld.
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Re: CAR AUDIO: Determining +/- on oem speakers/wiring
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Mon, 08 March 2004 12:36
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i was taught what i posted in my 1st post when i was working as an audio installer, to work out the phase of speakers easily in a system.
it worked for me well over the 8 year span that i did audio installs. i know i cant remember all i learnt (bloody comma, or was it that stuff i did when i was younger)... but i still remember a fair bit..
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Re: CAR AUDIO: Determining +/- on oem speakers/wiring
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Mon, 08 March 2004 13:46
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| THE WITZL wrote on Mon, 08 March 2004 15:24 |
| Quote: |
re: AC/DC
if speakers were running of alternating current you would have to send the earth back to the head unit/amp - but you can in fact earth it to the body. hence its all DC.
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DO NOT EARTH A SPEAKER'S (-) TERMINAL TO THE CHASSIS OF THE CAR!!!!!!!! It may work, but it is VERY BAD for both the speaker and the headunit. I do not know where you got this information but i suggest that you take it and throw it into the COMPLETE BULLSHIT pile.
Here is the method of finding out the correct phase of your speakers:
- Take one battery of any type (i like 9V)
- Find the pair of wires for the speaker in question and briefly touch the speaker's wires to the battery. Take note of which direction the speaker moves when it "pops"
- If the speaker moves OUT, you have the correct phase (wire touching + on battery is the + wire for the speaker). If the speaker moves IN when it pops, you have a reversed phase.
- That is all.
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Wow, that seems a bit rude. Did I ever suggest that it be done? Nope
Was my information incorrect ? nope.
Was it complete bullshit as you put it? nope
The reason I mentioned it was because that wiring setup was found on some amplifier wiring in a car, and sorry I can't remember where, I was just bemused at the time as to why people would bother wiring it this way. But I also realised that, well It would work. In fact the information was used simply to show the lack of an AC circuit.
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Location:
Sydney
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October 2003
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Re: CAR AUDIO: Determining +/- on oem speakers/wiring
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Mon, 08 March 2004 22:00
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thanks Karl, that was pretty much what I was trying to say...
which links back to my original post where I said it doesn't matter which way you wire it, as long as they are all the same. ie - all the speakers are IN PHASE with each other
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Location:
Menai area of Sydney
Registered:
June 2003
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Location:
Sydney
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October 2003
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Re: CAR AUDIO: Determining +/- on oem speakers/wiring
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Tue, 09 March 2004 02:14
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Woohoo someone agree's with me
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Location:
Newcastle
Registered:
May 2002
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Re: CAR AUDIO: Determining +/- on oem speakers/wiring
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Tue, 09 March 2004 04:03
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Ah here we are again arguing the semantics of the english language. Just one point, try not to hold a DC current (ie. 9V batt.) on the speaker terminals for too long as it can damage the voice coil. Hmmm interesting.
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Toymods Social Secretary
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Re: CAR AUDIO: Determining +/- on oem speakers/wiring
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Tue, 09 March 2004 09:03
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...and why I said a 1.5v AA will do the job as well. 
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Location:
UK
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May 2002
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Re: CAR AUDIO: Determining +/- on oem speakers/wiring
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Tue, 09 March 2004 11:50
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this thread could go on forever,so im giving up now
But the best way to make sure everything is wired up right is in this sentence.
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Location:
Bundaberg, Qld.
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May 2002
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Re: CAR AUDIO: Determining +/- on oem speakers/wiring
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Tue, 09 March 2004 12:20
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| Scorpion wrote on Tue, 09 March 2004 11:42 |
If your speakers are in phase (use the battery test and a 1.5v AA will do) as you move your head from one side of the car to the other you will not loose any sound. If your speakers are out of phase you will find that you loose sound in the middle which is where the out of phase soundwaves from the speakers null each other out. The same process can be applied to the front/rear aspects.
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which is basically the same as what i 1st posted. though i use some music and my ears, less bass response in the middle than when balanced to one side = out of phase.
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So to the original question, it doesn't matter which is '+' and which is'-' as long as all the speakers are set up the same way.
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i concur.
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