My speakers use outboard XOs so the two wires from each driver come out of the back of the enclosure. So, using those leads, can a driver DC resistance and voice coil inductance be measured with a LCR meter?
Thanks,
henrylrjr
Thanks,
henrylrjr
Will a signal generator be required or is the low DC output of the LCR meter all that is required?
The XO is entirely external???
Not likely to be the right way to work with an audio component unless you have a lot of knowledge about how LCR meters work or are clever in your lab skills (that is, cross-verify stuff by measuring components of known values).
Knowing LC or R values can be of no value - if using active crossovers. Inductance also likely not important because not big and/or not important in the tweeter range and/or not changing too much across range in question. And you need to know Back-EMF too, eh.
But if you are designing your own XO, then it is essential to learn the driver impedances at the intended XO frequency - and LCR meter will not help you but REW will.
Just justing an REW sweep and comparing device under test to known resistors is all you need to do to learn all you need to learn. See examples here:
https://www.diyaudio.com/forums/subwoofers/322418-17-foot-pipe-sub-12-230-hz-5db.html
Not likely to be the right way to work with an audio component unless you have a lot of knowledge about how LCR meters work or are clever in your lab skills (that is, cross-verify stuff by measuring components of known values).
Knowing LC or R values can be of no value - if using active crossovers. Inductance also likely not important because not big and/or not important in the tweeter range and/or not changing too much across range in question. And you need to know Back-EMF too, eh.
But if you are designing your own XO, then it is essential to learn the driver impedances at the intended XO frequency - and LCR meter will not help you but REW will.
Just justing an REW sweep and comparing device under test to known resistors is all you need to do to learn all you need to learn. See examples here:
https://www.diyaudio.com/forums/subwoofers/322418-17-foot-pipe-sub-12-230-hz-5db.html
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Inductance will vary with amplitude and frequency, so match the test signal to the application.
The DC inductance value will not be useful for speaker crossovers.
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I mentioned two leads from each driver come out the back. Those connect to outputs of outboard XOs.
We really need to be clear on why you want to measure the DC resistance and inductance of each of the two drivers.
As mentioned there are six leads, so three drivers. Reason is I was thinking about a Zobel circuit for the mid range and found a forumula that requires those values as inputs.
I saw no mention of that, but thanks for expanding your question.
Consequently, I withdraw the "two" I unwittingly placed in front of "drivers" in my post! 🙂
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My apologies. You are correct and I didn't say how many drivers. And to clarify a bit more, the Zobel will only be used in the mid range drivers, but I thought, if the measurements would be valid, I would check out all the drivers.
Zobel - a solution in search of a problem.
But check "sensitivity" of the formula - might not matter practically to know all the parameters accurately.
But check "sensitivity" of the formula - might not matter practically to know all the parameters accurately.
Would the results, of three test runs, indicate that the calculator is fairly sensitive? Entering DC resistance of 8ohms and voice coil inductance of 1mH returns 10uF cap and 10ohm resistor. Entering DC resistance of 6ohms and voice coil inductance of 1mH returns 17.8uF cap and 7.5ohm resistor. Entering DC resistance of 4ohms and 1mH of inductance returns 40uF cap and 5ohm resistor.
Sure, that's just a formula. But the L is somewhat ill defined and dependent upon
operating conditions.
operating conditions.
That formula is nonsense. You will need to find Le and Re for the speaker requiring correction, from an impedance and phase measurement at the crossover frequency you intend to use.
I was aware that I need to measure Re and Le so I started this thread by asking if an LCR meter could be used to measure Re and Le. After a few replies I learned that I would need equipment, that I don't have, to get valid measurements. Another reply asked about the sensitivity of the calculator so I did three test runs and posted the results. I wouldn't know if the results represent what might be considered a sensitive calculator.
These days , manufacturers of speakers supply plots of the impedance and phase response variation with frequency. This information will allow you to calculate Re and Le . While it is not a guarantee that what is published is going to be 100% accurate, given assembly tolerances and production changes, nevertheless for your purposes it should suffice in the absence of having access to test equipment.
And rayma is right too.
I think the Zobel concept is fixing a problem nobody has.
Without other unobtainable information about the drivers, your room, and other aspects of your system, there's no adequate way to design for proper sound at your seat. If you are committed to the old-fashioned passive XO, best to have a less efficient woofer and L-pads on louder mid- and upper-range drivers.