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Impedance Meter

This looks like what Sandman used to sell. It looks identical to the one I use. It works really well. I also have an University Sound LWT.

Check Ebay . I have seen these go for as little as $10. The tester is analog and it does take a little time to learn how to interpret the results, but it is a really good tester.

Rcaman

I've used the Goldstar units. They work very well and are extremely accurate. Reasonably priced.

Test it on a bench first. Set out a couple of speakers, hook them up to each other (without an amp) and connect the meter. Check the results compared to what you've connected. Try the different frequency settings, you'll get the hang of it quickly.

Sam

Ok, installed the amp today.

But!! Before I did, I checked the speaker grid with MY (new to me) TAO impedance meter.

I found one speaker wire at 60 watts. The rest of the speaker circuit was a little over 60 watts, total. I pulled the one wire out and tagged bad.

Given the size of the building and the fact that 70% is unoccupied(mostly storage) I decided to let the customer determine if there is a problem at any of their needed locations as opposed to trying to track down one speaker.

Hooked up the amp and tested, all ok.

Soooooo we be good.

Once again no weekend for me...............

Thanks all.

Les

Glad it worked out. Having the right tools can make all the difference.

Sam

I assume you mean TOA ZM-104 meter. That's a great meter. That will pay for itself within a few sound system service calls.

Rcaman

Yes it is a TOA ZM-104.

Not that enthused with the analog movement.

Arrived on site and my hands were full with shipping box of new amp and carrying the meter and the meter slipped out of my grip and hit the floor. When I first hooked it up I noticed that the dial face had shifted forward and the needle was dragging on the face.

Had to a total disassemble straighten the dial face and re-assemble.
Used a new speaker to verify calibration and all was good.

Needless to say feeling stupid, but, not ashamed enough not to post.

I feel that if my telling of my whoops may help someone else to be
extra careful with the analog meters. I would say that even though I was unlucky I was lucky enough.

Later,

Les

When it comes to instrumentation, I make it a point to carry ONLY the testing device and nothing else. Many decades ago, I was on top of an eighty foot tower with a Blonder-Tounge RF meter. At the time, that meter was well over $2,000. Being young and full of myself, I elected to forego the cumbersome strap that was to be slung around my neck to hold the meter. Instead, I thought I could hold the meter in one hand (it weighed about 40 pounds) and adjust the yagi antennas with the other. The meter slipped from my grasp and in a moment of sheer terror, I kicked out my foot off the tower and caught the falling meter with my foot. The meter banged on the tower and I had to contort my body in what was described as a "circus" maneuver to try and retrieve the meter which was dangling, precariously, from my left foot......which was getting a really painful cramp.

Fortunately, I was wearing a body harness which was clamped to the tower. I managed to recover the meter which was no longer functional. I descended to the ground only to find that the batteries had become dislodged and needed repositioned. The crew working with me NEVER let me forget that blunder. Since then, I take very much care with all the test equipment I use.

Rcaman

You could have just used a resistor, more accurate. Value of your choice but I would use several to cover the range.

-Hal