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Zip cord for speaker test
Zip cord for speaker test
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Old 10th June 2021, 10:34 AM   #231
Hans Polak is offline Hans Polak  Netherlands
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Quote:
Originally Posted by danny_66 View Post
Hi Hans,
how do you calculate the values of the LCR ?
Hi Danny,

In short:
To start with, measure with a VNA the open and shorted impedance of the cable.
This gave me resp the inductance and the capacitance of the 2.5meter 4mm^2 cable, resp 1.5 uF and 150pF. With sqrt(L/C) this confirms Zo=100R.

Now to get Zo=4R such as in my case, from 4=sqrt(1.5uHu/C) it can be calculated that C must be 93nF, so divided over 3caps gives 31nF per cap.
When simulating Zo in LTSpice, you will find that you still need a resistor and a coil in series with the cap, of resp 600nH and 9R, but taking into account the 150nH and 1R that the cap has, I needed resp. 450nH and 8R.
Be aware that these inserted LRC components better be able to withstand a few Amps to prevent added distortion.

Hans
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Old 10th June 2021, 10:38 AM   #232
Hans Polak is offline Hans Polak  Netherlands
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Quote:
Originally Posted by peufeu View Post
Does anyone know what's inside the mystery boxes on this MIT cable?
Sorry, I forgot the image.
Here it is.

Hans
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Old 10th June 2021, 10:52 AM   #233
Hans Polak is offline Hans Polak  Netherlands
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Quote:
Originally Posted by planet IX View Post
I would gladly repeat this experiment, but my speaker cables need to be a bit longer.
So should I repeat the network any 0,625 meters?
What cables do you have and how long are they ?

Hans
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Old 10th June 2021, 11:09 AM   #234
planet IX is offline planet IX  Germany
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At present I use a solid-core cable 2*1mm˛ (originally Siemens Profibus, I think)
I guess its 3-3,5m long, I can check it this afternoon.
I could also measure the impedance,as you described above.

I had MIT cables in the 90s, also some other not so cheap cables (Kimber, van den Hull). But then I once tried solid core cable (there are hunderts of meters in the Opt of my Tubeamp, was my thinking, so it coulnd't be that bad) and ever since then I use solid core loudspeaker cables. But I'm always open for new expereiences...
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Old 10th June 2021, 11:23 AM   #235
Hans Polak is offline Hans Polak  Netherlands
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Ok, when I know the inductance and the series resistance, I can do the calculation for you.

Hans
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Old 10th June 2021, 12:30 PM   #236
danny_66 is offline danny_66  Belgium
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Quote:
Originally Posted by Hans Polak View Post
To start with, measure with a VNA the open and shorted impedance of the cable.
Thanks for the guide.
A VNA is missing in my toolbox,
there are some cheap VNAs on ebay/banggood/Ali, what are the specs I should be looking for in a VNA ?
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Old 10th June 2021, 01:02 PM   #237
Hans Polak is offline Hans Polak  Netherlands
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Can you give me a link to such Alibaba device.
I’ll have a look at it and give my comment.

But you can also do a inductance measurement with the cable shorted at the other side.
And in the same way you can measure the DC resistance.
Those two parameters are the most important.

Hans

Last edited by Hans Polak; 10th June 2021 at 01:05 PM.
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Old 10th June 2021, 01:12 PM   #238
1audio is online now 1audio  United States
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Zip cord for speaker test
Look for Nanovna. They have a web site with lots of details. NanoVNA | Very tiny handheld Vector Network Analyzer Many variations out there. Watch for clones. All less than $100.
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Old 10th June 2021, 01:15 PM   #239
danny_66 is offline danny_66  Belgium
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Quote:
Originally Posted by Hans Polak View Post
Can you give me a link to such Alibaba device.
I’ll have a look at it and give my comment.
Here are some on banggood for about 50€
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Old 10th June 2021, 04:49 PM   #240
Evenharmonics is offline Evenharmonics  United States
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Quote:
Originally Posted by Hans Polak View Post
It amazes me that DIYers on this forum are spending large sums on all sorts of nice project in search of the holy sound grail, but when the option is there to possibly improve sound with very low cost manipulated LS cables, there is no animo.

And believe me, blind listening tests are not needed to hear the difference, it is so obvious, at least in my case.
Although no satisfactory physical explanations exists and although
Of course cables can make audible difference if they are bad enough.
Quote:
many people are prejudiced that cables cannot make a difference,
Where are those many people?
Quote:
wouldn’t it be a challenge to give it a try and leave your comfortzone for once.
All you need are 6 resistors, 6 coils and 6 caps plus 2*2.5 meters 4mm^2 zip cord.

Hans
Why should they try the cable equalizer when there are real equalizers out there.
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