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K-55 - What should my Ohm Meter be Reading?


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You're actually testing the integrity of the windings in the voice coil. Your meter should work fine, set it on the lowest scale for the expected resistance of what you intend to measure. For speakers, use the 200 ohm scale. It won't matter if you go red to red or red to black when your checking resistance, it's the same either way unless you're working on a circuit with a diode or other device in it, but straight wire is the same each way.

Just for kicks, take your meter around the house and test things using different scales. It's a good way to learn about using your meter and how it works, appropriate scales and what have you. In fact, you can probably go to the highest scale and press your fingertips firmly against the leads and get the resistance of your body from one finger to the other. Then lick your fingers and watch the resistance decrease.

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  • Klipsch Employees

That could be bad.

Meter set to Ohms<?xml:namespace prefix = o ns = "urn:schemas-microsoft-com:office:office" />

Set to the lowest value. "1k ohms", "200 ohms"

Touch the red lead to the black lead. The meter should show a reading. Note this reading.

Touch the red lead to one connector of the driver and at the same touch the black to the other connector of the driver.

This should show a reading, not too distant from the first.

The distance should be about 10.5 - 12 ohms.

If the meter reads nothing, you have a bad connection or open voice coil.

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Trey - I touched the 2 leads together and got .3
Then put them on the driver and got 9.9

On another squawker (different pair)... there are no prongs and there's solder everywhere. Not sure where to touch the leads exactly. Numbers fly all over the place so I think I'm doing something wrong on this driver.

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Does the meter have a "Zero" function/button? If so, press it while holding the leads together, that should give you a base of "0.000" to start with. Sounds like the first driver is just a tad low, probably not enough to be concerned with but will let someone with more knowledge of the effects of slight resistance changes and it's effect on sound weigh in.

The second squawker sounds like the meter is just getting a poor connection so the reading continually changes. Press the tips of the leads firmly in one spot, don't use the sides of the leads, see if that steadies the reading.

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the 2nd driver with the solder is fluxing between .4-.5 with touching just the tips to the solder. This is k-55-v soldered. (1981)

The first one that read 9.9 is k-77-m with prongs (1991 or 1993)

Edit - does it matter if they are hooked up to the turned off amp or not? Or crossovers?

Bob - I got the stuff back from you and plan to fire them up tonight. Thank you!

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If you still have .3 with the leads shunted together and .4 with them on the speaker leads it sounds like there is a short in the voice coil or the solder is touching somewhere. I'm sorry, but I'm not familiar with the soldered leads and how they look, hopefully Trey or Bob will hop back in, I'm sure they both know exactly what you're looking at. I'll see if I can find a decent pic of one.

And yes it matters!! Make sure the system is OFF! (See earlier post) They should have at least one of the leads disconnected from the crossover, both would be prefered.

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With the leads touching to themselves reading at .3, the k-55-v soldered reads 10.7-10.8. I've not done my others yet.

OK, so what's optimum and what signifies an issue.

Meagain is now asking the same question I posed earlier. What is the acceptable range for a soldered K-55V?

Mike

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Based on Treys' statement on the first page of the spec being 10.5 - 12 ohms, I'd say the acceptable range is 10.5 - 12.

I'm not trying to be a smartarse, but generally things that go down to a decimal point in resistance have a very low fudge factor. If you were to say +/- 2, that would be nearly 20% of your base measurement, which isn't very accurate. 9.9 might even be pushing it since it's off by .6 of the minimum, which would be 5% roughly, though I would think it would still function fine. I'm sure some wiser folk than I can chime in with the effects of lowering resistance on the sound.

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Here is a new K-55 diaphragm being measured for DCR. It will be hard to achieve this accuracy with a normal DMM because this one eliminates any error from lead resistance and the clips are gold plated to help insure the best contact. To get close to this accuracy, Short your meter leads together and record the reading. Then measure the reading you get measuring the coil. Subtract the first reading from the second.

Some batches of the coils will probably read a bit different from others, but this is not very important. A bad one will likely read open (infinite) or short (close to "0" ohms).

Bob Crites



post-9312-13819322036912_thumb.jpg

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Based on Treys' statement on the first page of the spec being 10.5 - 12 ohms, I'd say the acceptable range is 10.5 - 12.

I missed it in his reply. My only excuse is, he used a small font, because I'm guilty of what irrates me in too many posts: the members failure to read. But, Bob provided another good tip!

Many Thanks,

Mike

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