Hello,
Is someone aware of a brand tool to measure the inductance of our loudspeakers passive coils that is precise enough for the task to be usefull while not costing too much, please ?
I have not the monney for an expensive one nore I have an extensive need in the future but few loudspeakers refurbishing and one or two diy. I do not want either to purchase something that is not usefull because not precise enough for the job.
Well I am in europe so I surmise less choice than China and USA and btw shippment became expensive too. While Amazone warehouse have stocks in Europe.
Which unit to buy cheap and good enough ? Or the minimum items needed in the tool description to be able to chose one ?
I have also the jigg for Arta but I am not sure it is possible to measure the inductance without too much complex math for me.
Many thanks
Is someone aware of a brand tool to measure the inductance of our loudspeakers passive coils that is precise enough for the task to be usefull while not costing too much, please ?
I have not the monney for an expensive one nore I have an extensive need in the future but few loudspeakers refurbishing and one or two diy. I do not want either to purchase something that is not usefull because not precise enough for the job.
Well I am in europe so I surmise less choice than China and USA and btw shippment became expensive too. While Amazone warehouse have stocks in Europe.
Which unit to buy cheap and good enough ? Or the minimum items needed in the tool description to be able to chose one ?
I have also the jigg for Arta but I am not sure it is possible to measure the inductance without too much complex math for me.
Many thanks
Hi diyiggy,
Not sure what your price range is but I would reckon that this one is quite good (and also can be used e.g. for precision measurements of capacitors):
https://www.ebay.de/itm/260856045395?hash=item3cbc3b5f53:g:99gAAOSwZkJUTTe3
Price varies depending on add-ons. From Germany.
Cheers, Jesper
Not sure what your price range is but I would reckon that this one is quite good (and also can be used e.g. for precision measurements of capacitors):
https://www.ebay.de/itm/260856045395?hash=item3cbc3b5f53:g:99gAAOSwZkJUTTe3
Price varies depending on add-ons. From Germany.
Cheers, Jesper
You have to make a choice between off load and on load.
With an instrument you get a static measurement. So an off load reading.
An on load test will need to drive the speaker enough to move the coil as it would during listening. You get phase shift due to the coil moving through the poles of the magnet. The situation will end up escalating into a huge list of readings as you vary the power.
With an instrument you get a static measurement. So an off load reading.
An on load test will need to drive the speaker enough to move the coil as it would during listening. You get phase shift due to the coil moving through the poles of the magnet. The situation will end up escalating into a huge list of readings as you vary the power.
Hi Refugee1, sorry for my bad english, I was talking about the passive part of the filter : is inductance a better word than coil ? Or do we need also to measure this passive part loaded ? 2.83V trough the amp with a signal from a soundcard ?
Hello Jesper, how is advancing the dac pcb 🙂 ? Many thanks, much appreciated: it is just perfect as 100 euros was my limit ! And as I very few need it, no problem to have the display on a laptop if the usb also permit some graphics ! Deal 🙂
Thanks guys.
Hello Jesper, how is advancing the dac pcb 🙂 ? Many thanks, much appreciated: it is just perfect as 100 euros was my limit ! And as I very few need it, no problem to have the display on a laptop if the usb also permit some graphics ! Deal 🙂
Thanks guys.
If you are not measuring a speaker voice coil you can use a hand held component tester that will be priced easily within your budget. They are pretty accurate when compared to a vintage bridge.
The fixed inductors are just that unless they are carrying DC as well as AC. Your amplifier is faulty if the inductors in a cross over are carrying DC.
The fixed inductors are just that unless they are carrying DC as well as AC. Your amplifier is faulty if the inductors in a cross over are carrying DC.
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I think that’s the same as the one I have
https://uk.farnell.com/tenma/72-8155/multimeter-lcr-83x172x38mm/dp/1283643?st=Lcr meter
Seems good enough
Brian
https://uk.farnell.com/tenma/72-8155/multimeter-lcr-83x172x38mm/dp/1283643?st=Lcr meter
Seems good enough
Brian
Hi diyiggy ... Thanks for the question 😉 ... It is, however, progressing a bit slowly due to Murphy visiting an unusual amount of times 😳 ... My JLSounds board has been damaged three times now (my mishaps) and then - since I try to optimize the PCB into the miniature level - the DACs have also released their "blue smoke" a couple of times. So progressing slowly - but nevertheless progressing ...
Good luck with what you are doing!
Cheers, Jesper
I am in a total snail moment in my hobby too from several years, the tool is just to refurbish speakers for me or friends and try to finish my two last diy loudspeakers ! I have too much DACs and I am happy with what I have, though I have to finish a Moglia output tube stage for my Aya with a very good tube for subjective benchmark VS the solid-state one.
Ah, I ordered the kit in its most simple form as I need it few time ! There is a global transportation strike in Germany, and here in France the south beginns to be blocked because lack of full distribution because of social strikes too... hoping iy will not be lost in the middle of the path.
If it's precise at 0.5 % it's a very good item for the price. I saw the frequency range for inductance beginns a little late at 25k hz... but I have really no idea how the manufacters measures their loudspeaker inductances parts. The others I saw have at best a 2% precision under 100/150 euros.
Ah, I ordered the kit in its most simple form as I need it few time ! There is a global transportation strike in Germany, and here in France the south beginns to be blocked because lack of full distribution because of social strikes too... hoping iy will not be lost in the middle of the path.
If it's precise at 0.5 % it's a very good item for the price. I saw the frequency range for inductance beginns a little late at 25k hz... but I have really no idea how the manufacters measures their loudspeaker inductances parts. The others I saw have at best a 2% precision under 100/150 euros.
So, I finished to populate the ACSEL Electronic gentlevoice advised. Cost me less than 60 euros taking the minimal rs232 without tinsel and box. I PS it with a 9V cell that feeds the 7805 reg.
I do not know about the precision as all the inductances I measured, a dozen are not on spec, half are Mundorfs and just a 0.47 mH BL71 model is near with 0.45 mH.
two marked 3mH BL71 (1.63 ohms) are measured 2.75 mH
Two marked intertechnic air coil 0.22 mH are 0.26 mH (both). But some Mundordf CFC16 of 0.39 mH are 0.325 mH, the other 0.315 mH.
A no brand cored of 4 mH is measured 4.5 mH
A no brand 0.2 mH are measured 0.25 mH
Two no brand marked 0.5 with a white pen is 0.45 mH and 0.43 mH
Two no brand marked with a white pen 1.25 is measured 1 mH
That is a little terible if the measurement are acurate, or maybe not the rigth tool for bigh inductances ? Mundorf are so unprecise ?
I will retry with a full charged cell, hard to make a conclusion without a certified precise coil.
I do not know about the precision as all the inductances I measured, a dozen are not on spec, half are Mundorfs and just a 0.47 mH BL71 model is near with 0.45 mH.
two marked 3mH BL71 (1.63 ohms) are measured 2.75 mH
Two marked intertechnic air coil 0.22 mH are 0.26 mH (both). But some Mundordf CFC16 of 0.39 mH are 0.325 mH, the other 0.315 mH.
A no brand cored of 4 mH is measured 4.5 mH
A no brand 0.2 mH are measured 0.25 mH
Two no brand marked 0.5 with a white pen is 0.45 mH and 0.43 mH
Two no brand marked with a white pen 1.25 is measured 1 mH
That is a little terible if the measurement are acurate, or maybe not the rigth tool for bigh inductances ? Mundorf are so unprecise ?
I will retry with a full charged cell, hard to make a conclusion without a certified precise coil.
Inductance changes even with an air core coil with frequency and with level on a cored coil. And its a lot more significant than a resistor or even a cap. If you are characterizing inductors for a speaker then you need to check at different drive levels and different frequencies both in band and in the stop band. The measurements above may all be correct and may not be relevant to your application. However it can be useful checking parts to see if they are the same.
Thanks 1audio,
Are there please standardised frequencies the brands use to give the values of their inductances for loudspeaker filters, please ?
When ou say in band, you mean in the frequency range they are used for in the low pass if in serie or the high pass if parralel with the driver ?
So here with this device that check at 15khz - 750 k hz Sinus, said to have 10 nH precision below 1 mH and 10 uH above 1 mH up to 100 mH, the results are not good to know with precision enough (for instance 1%) the inductance in the usefull passband for loudspeaker application ? I.e. below the 15k hz of the frequency check ?
What not too much expensive tool the enthusiast hobbyst is needing for that task, any reference idea maybe ?
Are there please standardised frequencies the brands use to give the values of their inductances for loudspeaker filters, please ?
When ou say in band, you mean in the frequency range they are used for in the low pass if in serie or the high pass if parralel with the driver ?
So here with this device that check at 15khz - 750 k hz Sinus, said to have 10 nH precision below 1 mH and 10 uH above 1 mH up to 100 mH, the results are not good to know with precision enough (for instance 1%) the inductance in the usefull passband for loudspeaker application ? I.e. below the 15k hz of the frequency check ?
What not too much expensive tool the enthusiast hobbyst is needing for that task, any reference idea maybe ?
A dedicated instrument for measuring inductance to standards is expensive. However both ARTA and REW may be a ble to measure the impedance and calculate the incutance vs frequency. You would need a small power amp and a good reference resistor. I have used both but not in a while so you should ask someone more familiar with the programs on how to measure inductance.
In band would be the passband where the circuit passes audio. Stop band is where you want the audio not to pass. I usually model the circuit in LTspice to better understand what its doing and how component variations affect it.
In band would be the passband where the circuit passes audio. Stop band is where you want the audio not to pass. I usually model the circuit in LTspice to better understand what its doing and how component variations affect it.
I never was able to do the math by hand in Arta or REW after having measuref a coil. Never understood as well why they didn't included that function.
I have the test jigg box with a 22 ohms 0.1 % ref resistor but my brain isn't that acurate with math...what a pity...limited by design!
I have the test jigg box with a 22 ohms 0.1 % ref resistor but my brain isn't that acurate with math...what a pity...limited by design!
There were too much difference between the Mundorfs coils I have and the ACSEL kit.
I finally spent time to understand more the calibration in Arta Limp to measure the impedance of the coils and check some frequencies as the 15 k hz, same as Acsel kit but also at 1 k hz, 2 k hz ,500 hz, 100 hz.
No doubt now the ACSEL kit is not precise, does not really work with more than 10 to 15% of latch in the number even at 15 khz.
With Limp I was around 1% vis à vis of the voil marking, idem with the Z, taking 1k hz , 100 hz and 15 k hz.
I do not advice this kit, I will try to write to ACSEL ELECTRONIC but do not wait much as it is a kit and of course no conformity can be guaranted because of that !
The good new is Arta is working good if you spend a little time to understand the manual which is not very clear about the mV calibration of the channels.
Thanks for all the help provided. I certainly have no luck with my kit, but knowing Jesper and the quality of his diy work I have no doubt his is working.
Maybe the quartz or the precision of the resistors were not good enough as it is used as autocalibration. The quality of the pcb is not great either.
I finally spent time to understand more the calibration in Arta Limp to measure the impedance of the coils and check some frequencies as the 15 k hz, same as Acsel kit but also at 1 k hz, 2 k hz ,500 hz, 100 hz.
No doubt now the ACSEL kit is not precise, does not really work with more than 10 to 15% of latch in the number even at 15 khz.
With Limp I was around 1% vis à vis of the voil marking, idem with the Z, taking 1k hz , 100 hz and 15 k hz.
I do not advice this kit, I will try to write to ACSEL ELECTRONIC but do not wait much as it is a kit and of course no conformity can be guaranted because of that !
The good new is Arta is working good if you spend a little time to understand the manual which is not very clear about the mV calibration of the channels.
Thanks for all the help provided. I certainly have no luck with my kit, but knowing Jesper and the quality of his diy work I have no doubt his is working.
Maybe the quartz or the precision of the resistors were not good enough as it is used as autocalibration. The quality of the pcb is not great either.
I sorted out in that Pascal day the measurement problem with ACSEL design maker.
The device is selecting automaticly the fequency range of the caps and coils it is measuring in the 15 k hz to 700 k hz range when indicating capacitance or inductance results.
I measured a 2% LCR 1 nF polystyren tin foil cap and the board indicated 999,65 pF : correct and precise btw !
But for the coil at audio range it doesn't select the useful frequency range in the H and mH for inductance coils measurement where that values should be used for us : audio range. I tried 15 000 hz with Limp and very carefully calibrated dual channel soundcard with a 0.1% resistort test jigg. And here the ACSEL is not correct and is selecting a way higher frequency to indicate the iinductance that is not usefull for loudspeaker voice coils and more introduce errors. So it is clearly better for nH to pH high frequency measurement where it is correct as showed several low caps values till the pF range.
My understanding at measurring several Mundorf precision coils is the loudspeakers coils makers is giving inductance 100 hz or 1 k hz and here it is within the 2% precision with LIMP but 15% and more with ACSEL making the last useless for loudspeaker coils measurement.
At the end I am still happy to have that board for the day I will put my hands enthusiast HF (notice the oxymoron) designs : pcbs for pcm dacs for instance... the day I will sort out that mathh weakness if it ever happens, ah !
cheers and thanks again for all the tips given here about coils measurement.
The device is selecting automaticly the fequency range of the caps and coils it is measuring in the 15 k hz to 700 k hz range when indicating capacitance or inductance results.
I measured a 2% LCR 1 nF polystyren tin foil cap and the board indicated 999,65 pF : correct and precise btw !
But for the coil at audio range it doesn't select the useful frequency range in the H and mH for inductance coils measurement where that values should be used for us : audio range. I tried 15 000 hz with Limp and very carefully calibrated dual channel soundcard with a 0.1% resistort test jigg. And here the ACSEL is not correct and is selecting a way higher frequency to indicate the iinductance that is not usefull for loudspeaker voice coils and more introduce errors. So it is clearly better for nH to pH high frequency measurement where it is correct as showed several low caps values till the pF range.
My understanding at measurring several Mundorf precision coils is the loudspeakers coils makers is giving inductance 100 hz or 1 k hz and here it is within the 2% precision with LIMP but 15% and more with ACSEL making the last useless for loudspeaker coils measurement.
At the end I am still happy to have that board for the day I will put my hands enthusiast HF (notice the oxymoron) designs : pcbs for pcm dacs for instance... the day I will sort out that mathh weakness if it ever happens, ah !
cheers and thanks again for all the tips given here about coils measurement.