DMM help.
Thread Starter
50 Watt CAFz'r
Joined: Mar 2004
Posts: 146
I am trying to find out the impendance of my speakers,but when I switch my multimeter to make any measurements I get a 000 reading from it.
It's a Radioshack 14-Range Digital Multi meter, I switch it to resitance measurement @ 2Kohm--/20KOHM/ etc...and I still didn't get any decent reading from it.
How do I read the impendance of my speakers with it?
It's a Radioshack 14-Range Digital Multi meter, I switch it to resitance measurement @ 2Kohm--/20KOHM/ etc...and I still didn't get any decent reading from it.
How do I read the impendance of my speakers with it?
Thread Starter
50 Watt CAFz'r
Joined: Mar 2004
Posts: 146
Originally posted by Dukk:
Are you attempting to measure resistance or impedance?
Are you attempting to measure resistance or impedance?
2000 Watt CAFz'r
Joined: Jan 2001
Posts: 2,026
The 2Kohm to 20Kohm is way too high of a setting. that is looking for 2,000 ohms of resistance to 20,000 ohms - your 2,4 or 8 ohm coils would naturally read 0 for that setting.
How many settings do you have? Go to the lowest setting - not Kohm, or Mohm pure simple ohm. On my meter I think the setting is 200 ohm and under.
All higher settings essentially round the reading - (like 2000- 20,000 basically rounded the reading down to zero because on that setting the display is likely set up to show 2.0 for 2000 and 20.0 for 20,000 so the DMM would not register 0.004 for the speaker)
How many settings do you have? Go to the lowest setting - not Kohm, or Mohm pure simple ohm. On my meter I think the setting is 200 ohm and under.
All higher settings essentially round the reading - (like 2000- 20,000 basically rounded the reading down to zero because on that setting the display is likely set up to show 2.0 for 2000 and 20.0 for 20,000 so the DMM would not register 0.004 for the speaker)
Thread Starter
50 Watt CAFz'r
Joined: Mar 2004
Posts: 146
Originally posted by maltesechicken:
DMM aren't 100% accurate for reading impedance. I think they read the impedance @ 60hz but any other frequency is unrated so it won't give you a 100% accurate read - a ballpark though.
DMM aren't 100% accurate for reading impedance. I think they read the impedance @ 60hz but any other frequency is unrated so it won't give you a 100% accurate read - a ballpark though.
2000 Watt CAFz'r
Joined: Jan 2001
Posts: 2,026
I'm not 100% sure on that. I am positive that is the case for measuring wattage with a DMM but not sure if that is the case with measuring resistance. Even still their accuracy is around 75% (depending on how precise you want it be)
If you meter is 14 range then it should have a setting to read that low. Could you list the different possible settings found in the resistence section?
I'm guessing your ranges include ACV, DCV, DCA, Ohm and potentially one or two additional operating functions.
If you meter is 14 range then it should have a setting to read that low. Could you list the different possible settings found in the resistence section?
I'm guessing your ranges include ACV, DCV, DCA, Ohm and potentially one or two additional operating functions.
Guest
Posts: n/a
You aren't going to be able to read the driver's average impedance with a conventional DMM.
Your best shot at it is to use a voltmeter and a clamp on ammeter and use V=I*R to derive the impedance.
Even then - impedance will vary with frequency so it's a bit of a task.
The best way is to find a shop with a Rockford IM-1 impedance meter that can read it directly.
Your best shot at it is to use a voltmeter and a clamp on ammeter and use V=I*R to derive the impedance.
Even then - impedance will vary with frequency so it's a bit of a task.
The best way is to find a shop with a Rockford IM-1 impedance meter that can read it directly.
