question about hookin up speaker wires?

Terry Sneed · From: Arkansas,

I just bought a cab that I'm goin to put a 15" K-130 JBL in. The cab has the speaker wires already hooked up to the imput jack. Does it make a difference how the wires hook to the speaker? As you can tell, I'm real educated when it comes to simple stuff. Oh Well

Terry

Jerry Overstreet · From: Louisville Ky

I don't think it matters with just one speaker, but here's what I do just so's I know what's where. Using a continuity checker, I determine which soldered wire contact mates with the tip of the 1/4" plug. I call that one positive, the sleeve part, neg. I color code the wiring with a piece of red tape or some other identifiable marking.

This way, no matter what components I'm hooking together, I know I'll always have the correct phasing or at least know what's what.

Roger Kelly · From: Bristol,Tennessee

Jerry is right about one speaker....it doesn't matter. His advice about marking your existing wires so you will know what is what if you happen to add a speaker is good advice.
If your speaker is not marked with a + and - here is how to tell. Connect a 1 1/2 volt battery D or C size, to a short wire on each battery terminal, momentarily touch the battery wires to the speaker Terminals...if the Cone moves forward, toward the front, then the wire connected to the + side of the battery and speaker terminal is + and the other is -.
Do not hold the battery on the speaker, just swipe it so you can see the cone move.
Hope this adds to Jerry's already good advice.

Jerry Overstreet · From: Louisville Ky

So Roger's information will tell you which wire on the speaker is considered positive, right? Then you have to determine which lead from the amplifier the manufacturer has determined to be positive. Is that right?

In Peavey NV400 amps we know from Mike Brown's and Peavey's documentation that the yellow wire is pos.

Sorry if this is getting deep, but I'm trying to understand it all myself.

Correct me if I'm wrong, but if you momentarily plug in a 1/4" mono speaker cable to the powered up amplifier's speaker output and check the tip and sleeve at the loose end with a voltmeter, whichever way gives a positive reading will indicate which amp wire to the speaker is positive? This way, you can maintain polarity all the way from the amp to the speaker connections?

In stereo, or 2 speaker configurations, generally you want to have phasing be the same for both speakers. Sometimes, reverse phasing is desirable on one speaker too, so it's good to know how all your speakers are phased.

I know mfgs. of home stereo speakers where you have true stereo with multiple speakers, will tell you the connections with the best bass response is considered correct phasing.

Help me out here Roger. Exclamation

Pete Walthall · From: Arkansas, USA

terry wait about 2 weeks it will be for sale or trade they don;t make amps and guitars.that sute me and you.give me a call i lost your number or put your # up i will call you pete 870/574/1076

Roger Kelly · From: Bristol,Tennessee

Jerry, what you are saying seems right to me....however, if Terry has a speaker cabinet that is wired internally from the jack going to the speaker, then when he installs the 15" JBL in the cabinet all he really needs to do is determine the polarity of the speaker, and connect the wire coming from the Tip of the speaker jack to + on the speaker and the other to - on the speaker. Then he has a Aux. speaker that can be used with a Combo or Head. How he uses it with another speaker/amp would be determined by the impedance of the amplifier. Most Amp. Mfg's don't want you to go below 4 ohms total speaker load or Damage to Amp and Speaker could occur.

Ken Fox · From: Nashville GA USA

You might also be aware that most older JBL speakers are reverse polarity to other speakers.

Here is an in depth article on that:

In the golden olden days of speakers, the issue of whether the first motion of a cone was inward or outward, or polarity, was not uniform. Eventually it became standardized. Most speakers have an initial outward movement. When JBL started making speakers, they arbitrarily adopted reverse polarity and their speakers had an initial inward movement. This continued until JBL developed their musical instrument series speakers which used ¼” jacks. The use of these jacks required that JBL change their polarity to fit into what had become industry standards. Therefore, many of the older JBL speakers have reverse polarity, while newer models match what has become the industry standard.

Does this really matter? You can equate this to taking a 1 mile walk. It really won’t matter if you start with your left foot or right foot. Remember, we stock or can order JBL Recone Kits and JBL Diaphragms and a variety of other speaker parts.

JBL has published a technical bulletin regarding this. In it they define the terminology and list each specific speaker and its polarity.

Terminology: Positive systems: A system or transducer is said to be positive if a positive-going voltage applied to its red (or non-black) input terminal causes a positive pressure at the acoustical output of the device. For cone transducers, the cone will move outward and can be easily seen. For compression drivers, a positivegoing pressure can be measured at the driver’s exit. Many systems and transducers do not have color-coded input terminals, and in these cases one terminal is usually labeled with a + sign. Consistent with the positive standard, a positive- going signal at the positive terminal will result in outward motion of the cone. Negative systems: A system or transducer is said to be negative if a positive-going voltage applied to its red (non-black) terminal causes a negative pressure at the output of the device.

Polarity of JBL Professional systems and transducers: The following is a comprehensive listing of former and current JBL Professional systems and transducers by product category. Within each category models are indicated as positive or negative. The obsolete models included here are those that are still supported by company repair service and spare parts.

Musical instrument transducers: The following models are negative: E110-8 E120-8, 16, E130-8 E140-8, E155-4, 8. The following models are positive: M121-8, M151-8

Jerry Overstreet · From: Louisville Ky

Thanks Roger and Ken. I'm sorry Terry to get so technical on this issue. It's just something that I've always been unsure of.

So, all that aside, seems like your connection is of simple mono use and following Roger's and Ken's sage advice should work for you.

Thanks for letting me dig a little deeper into this on your topic.

Ken Fox · From: Nashville GA USA

Roger's advise on finding speaker polarity is very good, indeed. I use that method as well in the shop, I use an 18 VDC drill battery.

"Correct me if I'm wrong, but if you momentarily plug in a 1/4" mono speaker cable to the powered up amplifier's speaker output and check the tip and sleeve at the loose end with a voltmeter, whichever way gives a positive reading will indicate which amp wire to the speaker is positive? This way, you can maintain polarity all the way from the amp to the speaker connections? "

That will not work. Amplifiers put out an alternating current. On Peavey amps the yellow wire is positive phasing of the alternating audio signal and blue is the opposite phase (and is connected to the chassis ground terminal of the speaker output jack).

Old JBL speakers were in fact using red as negative and black as positive. You can't even trust that as some have been re-coned with generic kits. Found that in a Twin reverb a while back. Had two D-120F and one had been reconed with red as positive. Poor amp sounded sick, until I got the speakers back in phase.

Terry Sneed · From: Arkansas,

Thanks to all for your help, but I'm still not sure I understand. The speaker I'm getting is a K-130 reconed. I'm thinkin I may buy another speaker and cab soon, so I'll have two speakers so to give me a better tone. I'm using a Vibrosonic Head which I think is just like a Fender twin except it had one 15" speaker instead of two 12's. So, later on, can I hook up another K-130 8 ohm, and how would I need to hook this single speaker up, so to match the other one, when and if I decide to get another speaker and cab? The two wires coming from the imput on the cab are black and white. sorry for being so clutter headed. Confused

Terry Oh well, I'll get er figured out. thanks again.

Pete, I'll call you in a few days. Maybe it will cool off a little, it was 118 degrees on our front porch today. And my cell phone won't pick up inside the house anymore for some reason. I have to go outside. But I will call you just as soon as we get a little break from this heat wave. Terry

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