I need wiring help (+ and -)

[dmginter]

My home is prewired. I think it is either 12 or 14 gauge and is hidden in the walls.

The problem I have is that there are not any markings or color difference in the wire. I can not tell what is positive and what is negative.

Any ideas on how to hook up my speakers correctly not knowing what is + or _?

Or any ideas on how to test the speakers after they are connected to the amp?

Thank you,

[Ron-P]

Do you have an Ohm meter?


Peace Out~:D

[TonyPTX]

Originally posted by dmginter

Any ideas on how to hook up my speakers correctly not knowing what is + or _?

You can use a tone generator that you can pick up at Home Depot or Lowes. Or you can use a low current source such as a battery and a small bulb to wire a circuit to test which wire is which.


Or any ideas on how to test the speakers after they are connected to the amp?


Simplest way is to pick up a calibration DVD such as the Avia, VE, or S&V and use the speaker phase test to determine if your speakers are in phase or not.

Hope this helps. I'd find the contractor who built the house and shove a tweeter horn up his arse for not labeling. It's almost as bad as not labeling the breaker box!!!!

[dmginter]

What do I do with the OHM meter?

[Ron-P]

Like this one below ($15 from the Rat Shack). It's an AC/DC volt meter. You can set it to test for continuity. Touch each end of the meter's probes to your wire ends and when you end up on the same wire, the needle will jump. Now you know you have the same wire, label it and your done.

http://www.radioshack.com/images/ProductCatalog/ProductImage/22/22-218.jpg


Peace Out~:D

[RuSsMaN]

Outside of the suggestions listed above, your ears are always a good tool to use. If your speakers are wired out of phase, they should lack in the bass dept (compared to being properly wired), and sound sort of veiled, or hollow.

You *should* be able to hear a difference.

Cheers,
Russ

[dmginter]

Re: Ohm meter

How do I tell which wire is positive and which one is negative?

Thank you,

[HBombToo]

it does not matter. you assign as you would like. the meter just assures continuity.

HBomb

[TonyPTX]

Not that an Ohm meter isn't a bad idea, it's that it's application here would be difficult. Usually one end of a wire is in one wall and the other end could be on a completely seperate wall or room for that matter. Either you need really long leads on the ohm meter, or you're gonng to have to run a seperate wire between the two points which may not be the easiest thing in the world to do.

[dmginter]

The speakers are + and -. The amp is + and -. I do not know what the wire is. Besides using my ears, how can I test to see that negative on the speaker is hooked up to negative on the amp?

Will the Ohm register negative if it is hooked up wrong (negative to positive)?

[RuSsMaN]

It doesn't matter which wire you use for pos / neg, pick one, hook it up and listen.

[wlrandall]

Get one of the 9V battery connectors from Rat Shack. Twist the ends to the speaker wires, clip on a battery. Check voltage at end of run. If display is negative, switch leads to reduce confusion. With the meter reading +9V, you know have a red wire at each end of wire #1 and a black wire at each end of wire #2. Mark 'em and you're done.

[schumach]

Here is a very simple and inexpensive way to test the wires.
1- you need a 9volt battery, a red LED (9 volt) and two people.
2- have one person touch the leads at one end of the wires the 9-volt battery. One to the negative side of the battery the other to the positive.
3- the other person touches the LED to the other end of the wires. The LED will only light up when the negative side of the LED is on the negative side of the battery (If I recall correctly that would be the flat side of the LED, sorry too lazy to go out to the garage and check). Make sure you get at least a 9-volt LED, but nothing more than a 24-volt, Good luck and hope this helps.


Greg

[RuSsMaN]

How about just hooking them up and listening? It should be fairly obvious which sounds better.

'Lets not make it complicated'

Sheesh, we've got volt meters, LED's, Batteries, Battery leads. Not saying they aren't correct suggestions, but why re-invent the wheel, without using your own God-given tools a shot first?

I've got a lightbulb that needs changing, any suggestions?

;)

Cheers,
Russ

[dmginter]

Does it make a differance?
Will someone try changing the + to - on there system and tell me if they can tell?

[RuSsMaN]

First, if it DIDN'T make a difference, why worry about it to begin with?

Second, if it DIDN'T make a difference, why would I waste time typing it out to you, repeatedly at that.

You've got your rig in front of you, don't ya? Try it man, TRY IT. If you don't want to, for some reason, get busy on a suggestion above. You have a multitude of suggestions RIGHT in front of you.

Cheers,
'Looking California, but feeling Minnesota' Russ

[dmginter]

No I do not have an amp., should be here soon.
My guess, half the people on this board have + connected to - and don't know it.

[RuSsMaN]

Originally posted by dmginter
No I do not have an amp., should be here soon.
My guess, half the people on this board have + connected to - and don't know it.

I'm at a loss for words now, no where to go from here - but down. Hope it works out for you when your amp shows.

[scottvamp]

My guess, half the people on this board have + connected to - and don't know it.
WOW! I better check this + and - thing out.:eek:

[HBombToo]

Are you guys telling me I traded in a perfectly good Carver, "Following the suggestions from the forum", on a SONY! and it could of been this plus/minus thingy?????????????

You bastards! every 1 of ya!

I Quit! I'm gonno go and buy a Bose dammit!
HBomb

[Tour2ma]

Serenity, Russ... serenity NOW DAMNIT... ;)

dmginter,

When you get your amp, hook up the speaker leads. What Russ and others are saying is take a shot; you cannot hurt anything if you mis-guess.

Once wired up, turn on your amp and tune your FM tuner to between stations (this creates a monophonic hiss, a po-boy's white noise if you will), and then go and stand directly between your speakers and listen.

If the hiss is coming from directly between your speakers, your speakers are wired in-phase.
If the hiss is coming from "outside" of your speakers, your speakers are wired out of phase. Shut the amp down (never wire with the amp on) and switch one of the leads at one end only. Speaker end will likely be easier, but your choice. Performing a retest after the switch should find the hiss focused between the speakers.

As for the true "+ 2 +/- 2 -", Russ is right, you probably can't tell the difference, but if you want to try to, just put on a favorite piece of music, listen to it, shut all down, switch both pair of leads at the speakers and replay the same piece. Better? Worse? Same? Switch back, or not...

OK so far? Good, but now…

At the risk of confusing matters even more, there is one ohmmeter test I would definitely recommend you conduct - a ground fault check of your speaker wiring. To do this:
- be sure none of the stripped wire ends are touching;
- at one end of one run check the resistance between the two exposed leads by pinning the wire’s leads to a non-conductive surface like a wooden cutting board with the ohmmeter’s probes (why like this? Because if you pinch the ohmmeter leads to the wire between your thumb and forefinger you end up measuring the resistance of your body… try it by just holding an ohmmeter lead in each hand… me, I’m about a 150 ohm kinda guy); and
- repeat this for the other speaker lead.
In this test you are looking for ultra-high resistance. If the check shows a low resistance, like “zero”, that wire has been damaged and cannot be used.

It's not likely the above test will show a problem, but wire can be damaged during in-wall pulls, especially if the wiring was run after construction.

In fact, in playing around for this reply I found I damaged a wire in a recent pull. Looks like I’m off to Home Depot today. WTH. I needed more wire for my surround pulls anyway.

Good luck, and if you have more questions, please ask…

And welcome to the Club…

[HBombToo]

Excellent Read Tour2ma!... and right on the mark.

HBomb

[dmginter]

Thank you

[shiu]

I am sure most, (likely all) people in this forum could tell the difference if the +,- are reversed for one channel, but not both channel. If you reverse the + and - for both left and right channel, you should be fine (in most cases). As someone pointed out, all you have to do is listen to mono music, or something that has a lot of bass.

[RuSsMaN]

Originally posted by shiu
If you reverse the + and - for both left and right channel, you should be fine (in most cases).

And what cases would that be? Wire em' all out of phase and it *should* be ok? Dry that one out and fertilize the lawn.

[shiu]

Audio signals are a.c., so in the case of two channels only, yes it should be okay if you reverse the polarity in both side. Okay this is for argument sake and I know many disagree. I too, would always connect them + to +, - to -, just in case there are other factors I do not know about.

[RuSsMaN]

How would it be 'ok'? Would it work? Sure.

Will it sound like a big bag of puppy poo? Probably.

[Tour2ma]

Originally posted by dmginter
My guess, half the people on this board have + connected to - and don't know it.

Actually Russ a change in absolute polarity across all your speakers is not that noticeable.

The SDA troubleshooting info that Lauren sent me adds this little gem to the mix. And I quote:
“With some amplifiers, the common inter-channel connection is made through the positive terminals, rather than the negative. In this case the speakers behave as though both units were connected in the reverse phase…”

So + could really be -, and vice versa. :confused: And dmginter may be a prophet…

One old trick I did not mention earlier. Pick a track with a deep, strong drum thump that stands relatively alone. Examples that come to mind are the floor tom/ bass drum at the end of Rod Stewart’s “I’m Losin’ You” off of Every Picture Tells a Story and the tympani in Richard Strauss’ Also Sprach (Thus Spoke) Zarathustra. Hold a lit match or candle in front of your main’s woofer. If the thump tries to, or succeeds in, blowing the flame out....

Actually in the above you need to see the woofer’s cone intially “push out” in reproducing the drum thump. Reverse polarity will make the woofer cone “suck in” as its first move to reproduce the drum kick. In either case, air ends up being moved forwards and given enough air volume, i.e., amplitude, the flame will go out.

But it’s so cool to actually blow out a flame! Used to do this for kicks with my college roomie’s KLH-5’s. Actually he was not as fond of this pastime as I was. Even my old Lafayettes could do this… :cool:

So Shiu and Scott, better dig up your amps’ manuals… or break out your ohmmeters, the mention of which kind of brings us full circle here… God bless symmetry…

Edit: One last thing, I will not be held liable if anyone sets their speakers on fire…

[burdette]

A cheap multimeter is a good thing to have around the house regardless, just to check if you've turned off the correct circuit breaker, or to see if the wire you're about to grab is hot. So that purchase does not have to be construed as 'audio only.'

With that meter, all you need now is a battery.. ANY battery.. does not have to be 9v. Just hook the speaker leads to the battery on one end of the run (use a little masking tape). Mark the wire on the positive terminal of the battery. Go to the other end of the run, check the wires with the multimeter... when you get a reading of a positive voltage, then the red lead is touching the wire that is on the positive terminal of the battery.. mark it.. and you're done. No need for an LED or a 9v...

This method works for ANY wire run.

[shiu]

tour2ma, thanks for the advise. My comments was purely based on my understanding of some of the law of physics and engineering. I have never actually tried hooking the speakers (both L&R) reversed. I read an article not long ago about some speaker manufacturers have their products done in the opposite polarity. I don't know how true that is.

[Tour2ma]

Shiu,

Of course Polk doesn't do that (Do they, Ken?), but you're right some manf's do...

So if you have + common ground amp and reversed speakers, then you're OK also. Guess that proves that two wrongs can make a right... :)

[shiu]

I hope not, my 5.1 system is 100% Polk.