Finally got me a clamp meter

[knukonceptz 10+ year member]

Can I check voltage for gains?

Are you talking about matching your amp gains?

 

[Flipx99 5,000+ posts]

yeah

 

[knukonceptz 10+ year member]

Do you have more then one sub amp? Matching your amps output to one another is only required if you have more then one sub amp. Your F/R amp only need to be matched by ear to play with the subs. If you have two sub amps, they need to be matched to avoid cancellation

 

[smullen 10+ year member]

As far as I know a ""Clamp Meter"" is just to measure Amperage...

With Voltage you take a reading by connecting the test leads in Parralel....

With Amperage, you have to connect them in Series so the amperage can flow through it.

If you were to connect those puny lil test leads in Series to say a large Sub Amp, a Starter or anything that pulled a decent ammount of current, the "Test Leads" would melt...

So, some genious came up with an idea of a "clamp Meter" for checking amperage, you just clamp it on/around one side (+ or -, not both) and it will tell you the real time amount of current being passed though that circuit...

Now some clamp meters may also have a VOM or DMM built onto them to test Voltage, Impeadance and Continuity...

I have a Fluke DMM....

 

[Flipx99 5,000+ posts]

There are two different settings that say v on them. WHich one should I chose?

 

[Flipx99 5,000+ posts]

Set your meter to measure resistence and put the leads to the terminals. Ω

I did this on some 5.25s that I had laying around and it made a beeping noise.

 

[jrz126 10+ year member]

As far as I know a ""Clamp Meter"" is just to measure Amperage... With Voltage you take a reading by connecting the test leads in Parralel....

With Amperage, you have to connect them in Series so the amperage can flow through it.

If you were to connect those puny lil test leads in Series to say a large Sub Amp, a Starter or anything that pulled a decent ammount of current, the "Test Leads" would melt...

So, some genious came up with an idea of a "clamp Meter" for checking amperage, you just clamp it on/around one side (+ or -, not both) and it will tell you the real time amount of current being passed though that circuit...

Now some clamp meters may also have a VOM or DMM built onto them to test Voltage, Impeadance and Continuity...

I have a Fluke DMM....

It's not the test leads that would fail, but the unit itself. (well the leads would fail too if you tried measuring the current from the starter)...but anyhoo, the way those amp meters work is by placing a resistor with a very low resistance (lets say 0.1 ohm) in series with the circuit to be measured. Then the meter would measure the voltage drop across that resistor. Then using good old ohms law, the current is = to (voltage across resistor)/(resistance).

Now this becomes a problem when you are trying to measure high currents in 2 ways: 1. the voltage drop created by the resistor in the meter. (say you are measuring a 12V, 10amp unit with the meter, there will be a 1v drop across the meter, giving you only 11V to the unit.) and 2. the power disipated by it. power=I^2*R (at 10 amps and .1 ohms, you'll need a 10 watt resistor inside the meter).

Hmmm...I could talk about this stuff for hours...

Oh yeah and Flukes > all

 

[Flipx99 5,000+ posts]

Do you use the V- - - - or V----- when testing voltage at the amp?

 

[maylar 10+ year member]

You use AC volts. Sometimes they show the AC symbol like a tilda ~

 

[jrz126 10+ year member]

the - - - - is probably the AC measurement.

 

[slim j 10+ year member]

I did the gains thing and I was actually able to turn it up some, it also sounds a lot clearer. My trunk light blinks for some reason, so I believe it to be defective.

Also, when I put the ohm part on my speaker wires, I got 6.3. When I put it on a 2-ohm coaxial I got 7.0. Why am I getting so many ohms? Is my dmm defective. Since i have two dual 4 ohm subs, shouldn't I be getting 1 ohm?

 

[jrz126 10+ year member]

Depends on how you have them wired. Are you sure the coaxial should have been 2 ohms?

Try connecting the leads of the DMM together, if it reads 0 or close to it, then the meter should be good.

Also, how fresh are the batterys in your meter?

 

[slim j 10+ year member]

I would assume they are pretty new. They come with the meter.

I just tested some coaxials laying around in my room. They are kenwood 4-ohm 5.25" speakers. I put the new clamp meter and it makes a loud beeping sound and has 4 ohms in the display. It does not have decimal places.

My old dmm has 4.5 in the display.

 

[knukonceptz 10+ year member]

The beeping means there is continuity and the resistance is shown on the display. If you heard no sound and 0 was on the display that is an open coil = bad speaker. Want another neat trick, push on the cone while measuring ohms

What are you guys setting your gains with on the DMM? If you have a single sub amp a DMM really will just let you know output. You would need an Oscope to see if it is clipping, nothing a DMM can do to set gains unless you are matching two sub amps outputs.

As for your resistance , are you measuing with the amp connected? Also if the speakers have been playing they will show higher

 

[Flipx99 5,000+ posts]

Ahh...didn't check the display. I stopped when I heard the beeping noise because I didn't want to break it. CHeck out j-mac's gain setting tutuorial in the amplifiers section. That is what I am using.