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What Electrical Property Governs Cable Design? - Page 2

post #16 of 45
Quote:
Originally Posted by StanD View Post
 

Probably that not as much as you may think as we hear in a logarithmic fashion. The cable would have to be 32 Ohms to make a -6 db loss,  a 5 Ohm cable resistance would  result in a -1.26 dB loss and a 1 Ohm cable resistance in  a -.27 db loss.  See the below equation.

20 * log(32 /( CableResistance + 32))

 

My point is just that I doubt that 1 ohms is the highest measuring resistance in a cable ever. Although in most cases there would be a likely inaudible FR shift as a result of using a different cable, I believe that there are likely a select few cables which will result in differences.

post #17 of 45
Quote:
Originally Posted by SanjiWatsuki View Post
 

 

My point is just that I doubt that 1 ohms is the highest measuring resistance in a cable ever. Although in most cases there would be a likely inaudible FR shift as a result of using a different cable, I believe that there are likely a select few cables which will result in differences.

The key word is "inaudible" of which too many people make up all sorts of stories about hearing what is not truly happening.

post #18 of 45
Quote:
Originally Posted by StanD View Post
 

I use the shorter cable,mainly because of the plug size as well as the length is tidier. OK I just unplugged that cable, it's 0.2 Ohms. It's late and I'm not going to mess with my HD600's or Momentums.

 

*thumbs up*

What's the stock cable length, 3 meters?

 

 

Anyway, no matter how expensive (or cheap) the cable is, you cannot escape physical laws. The longer and thinner the cable, the higher the resistance.

post #19 of 45
Quote:
Originally Posted by xnor View Post
 

 

*thumbs up*

What's the stock cable length, 3 meters?

 

 

Anyway, no matter how expensive (or cheap) the cable is, you cannot escape physical laws. The longer and thinner the cable, the higher the resistance.

Yep, the stock cable is 3 meters long and the short cable is 4.5 foot long and is $12.95. Any reasonable quality cable at a reasonable length shouldn't pose problems. If I'm on the move I use my smartphone with a portable DAC/Amp of which both fit in my pocket so I don't need a long wire to trip over.

High impedance devices like electric guitars are sensitive to cable capacitance and even far less sensitive to the resistance of the cable than headphones of which isn't such a big deal. If you increase the capacitance and impedance then you'll start lowering the corner frequency and eventually affect audio.

Audio cables seem to be a lucrative business.

post #20 of 45

Would be fun to post the original question on a cable looney tread:popcorn:LOL

post #21 of 45
Quote:
Originally Posted by StanD View Post
 
Quote:
Originally Posted by xnor View Post
 

There seem to be some rare cases where the stock cable actually measures a few ohms.

Defect? What brand what model? If the cans are 300 Ohms like an HD600, it may not make any difference in a change of loudness. A few Ohms and a few hundred pF of capacitance won't have any affect on audio frequencies.


I remember reading something about a stock cable for westone or shure that was above 3ohm. but it was by choice.

I understand that shielding will increase the cable impedance, but I have no idea in what proportion.

post #22 of 45
Quote:
Originally Posted by Steve58 View Post
 

Would be fun to post the original question on a cable looney tread:popcorn:LOL

I got in trouble once for interjecting truth into one of those looney threads. 

post #23 of 45
Quote:
Originally Posted by castleofargh View Post
 


I remember reading something about a stock cable for westone or shure that was above 3ohm. but it was by choice.

I understand that shielding will increase the cable impedance, but I have no idea in what proportion.

Don't know why they'd purposefully increase the resistance.  Increasing the shielding shouldn't increase the impedance. It may actually decrease the resistance of the ground return if that's done by the shielding. It might also increase the capacitance which decreases in impedance as the frequency increases (reactance) and effectively forms a high frequency roll off or if the numbers are right, rolls off treble or even starts lower in frequency. In a different circuit you can do the opposite with a capacitor and roll off bass, which is not the case with cables.


Edited by StanD - 12/16/13 at 5:31am
post #24 of 45
Quote:
Originally Posted by StanD View Post
 

Don't know why they'd purposefully increase the resistance.

 

I have also seen headphone cables with a few Ω of resistance, and cheap extension cords with a total of 10 Ω resistance (5 + 5 Ω for signal and ground, which also means worse than -20 dB crosstalk with typical 32 Ω headphones). Not sure about the reason, perhaps the wire is some special material instead of pure copper to make it harder to break, but it is only a guess. With random "no name" 1/8" jack to RCA cables (intended for line level signals) that are not very long, I measured less than 1 Ω, as expected.

 

Quote:
Originally Posted by StanD View Post
 

It might also increase the capacitance which decreases in impedance as the frequency increases (reactance) and effectively forms a high frequency roll off or if the numbers are right, rolls off treble or even starts lower in frequency.

 

It would require an unusual amount of capacitance to audibly roll off the treble with a reasonable headphone output (not more than 100 Ω output impedance, and that is already bad). With 10 nF capacitance (which is higher than typical) and 100 Ω output impedance, the -3 dB frequency is at ~160 kHz, while the attenuation at 20 kHz is less than 0.1 dB. Of course, one would have more reasons to worry about the output impedance, if it was really 100 Ω, because that could easily have audible effects by itself.

 

On the other hand, cables with high capacitance may cause stability problems in some amplifiers.

post #25 of 45
Quote:
Originally Posted by stv014 View Post
 

 

I have also seen headphone cables with a few Ω of resistance, and cheap extension cords with a total of 10 Ω resistance (5 + 5 Ω for signal and ground, which also means worse than -20 dB crosstalk with typical 32 Ω headphones). Not sure about the reason, perhaps the wire is some special material instead of pure copper to make it harder to break, but it is only a guess. With random "no name" 1/8" jack to RCA cables (intended for line level signals) that are not very long, I measured less than 1 Ω, as expected.

 

 

It would require an unusual amount of capacitance to audibly roll off the treble with a reasonable headphone output (not more than 100 Ω output impedance, and that is already bad). With 10 nF capacitance (which is higher than typical) and 100 Ω output impedance, the -3 dB frequency is at ~160 kHz, while the attenuation at 20 kHz is less than 0.1 dB. Of course, one would have more reasons to worry about the output impedance, if it was really 100 Ω, because that could easily have audible effects by itself.

 

On the other hand, cables with high capacitance may cause stability problems in some amplifiers.

Yep, somewhere in this thread I mentioned none of this should affect audio frequencies. True about high capacitive loads causing instability in an amp as the reactance gets too low for the amp to handle at higher frequencies and worse. In any case a normal quality cable should have no such problems. I wouldn't expect to get something like that from Sennheiser.

I've covered a lot of these technical details in some threads where people were going on about overpriced magical cables and hear all sorts of improvements, IMO imagined, and get mad about the technical realities and will deny them. I guess after spending hundreds of dollars on such cables, one has to be affected by some form of Placebo Effect. God bless them and they should get some joy from tinkering as that's part of the joys of the hobby. :rolleyes:

post #26 of 45
Quote:
Originally Posted by StanD View Post
 

I've covered a lot of these technical details in some threads where people were going on about overpriced magical cables and hear all sorts of improvements, IMO imagined, and get mad about the technical realities and will deny them.

 

^ By no later than that you should seriously rethink the hobby, or any hobby really.

post #27 of 45
Quote:
Originally Posted by StanD View Post

Yep, somewhere in this thread I mentioned none of this should affect audio frequencies. True about high capacitive loads causing instability in an amp as the reactance gets too low for the amp to handle at higher frequencies and worse. In any case a normal quality cable should have no such problems. I wouldn't expect to get something like that from Sennheiser.
I've covered a lot of these technical details in some threads where people were going on about overpriced magical cables and hear all sorts of improvements, IMO imagined, and get mad about the technical realities and will deny them. I guess after spending hundreds of dollars on such cables, one has to be affected by some form of Placebo Effect. God bless them and they should get some joy from tinkering as that's part of the joys of the hobby. rolleyes.gif

At that point its just show off in the guise of a hobby.
Its like in sports, some believe getting the best tennis racquet, one used by top ranking player, will magically turn them into a better player.
Or some just buy expensive stuff to show off, others try to do the same (in-group phenomenon).
post #28 of 45
Quote:
Originally Posted by xnor View Post
 

 

^ By no later than that you should seriously rethink the hobby, or any hobby really.

I begin to wonder if they even enjoy listening to music.

post #29 of 45
Quote:
Originally Posted by proton007 View Post


At that point its just show off in the guise of a hobby.
Its like in sports, some believe getting the best tennis racquet, one used by top ranking player, will magically turn them into a better player.
Or some just buy expensive stuff to show off, others try to do the same (in-group phenomenon).

I think you're onto something. They don't really enjoy music, they enjoy bragging rights but only based upon myth and so the emperor hath no clothes.

I think I need to listen to some music. No silver cables or $2000 amps or $5K cans. I'll use my HD600 with OEM cable and an SS amp that doesn't cost a fortune yet can drive the cans cleanly with plenty of headroom....and be happy. I'll save my dosh for a good lens for my camera, unfortunately bending light comes at a price.

post #30 of 45
Quote:
Originally Posted by StanD View Post
 
Quote:
Originally Posted by castleofargh View Post
 


I remember reading something about a stock cable for westone or shure that was above 3ohm. but it was by choice.

I understand that shielding will increase the cable impedance, but I have no idea in what proportion.

Don't know why they'd purposefully increase the resistance.  Increasing the shielding shouldn't increase the impedance. It may actually decrease the resistance of the ground return if that's done by the shielding. It might also increase the capacitance which decreases in impedance as the frequency increases (reactance) and effectively forms a high frequency roll off or if the numbers are right, rolls off treble or even starts lower in frequency. In a different circuit you can do the opposite with a capacitor and roll off bass, which is not the case with cables.

 

I can't really find anything with real life exemples and values, and formulas often get too complicated for a dude who stopped school 15 years ago and math/physics even sooner ^_^. 

all I can find talks about high freqs as in radio freqs, but nothing simple or really relevant to my eyes (meaning: that I can understand) in the audio range.

 

 

I was thinking about an increase in impedance from shielding like this:

signal in the cable generates magnetic fields that will create a signal in the the shielding material that will itself create back magnetic field that should in the end oppose voltage in the cable in some ways no? I don't know if this super inefficient transfert can matter at all, but as it depends on ... voltage?(I'm guessing it's voltage for magnetic field) ... the changes arent linear and might matter in some ways. I just have no idea about the values of such effect.

 

also what I really know nothing about is how the shielding material behaves on portable stuff (like IEM cable) where it's etheir not grounded at all, or linked to the circuit ground of the cable itself? I really don't know much about all this, but my little pinky told me proper shielding shouldn't be like that.

 

 

 

 

 

and about the cable with a few ohm, again from a very insecure memory, I believe the purpose was to make a little change in signature thanks to the weird impedance/freq caracteristics, to ease up on a given frequency range. I guess it was a situation not unlike the W4 where the signature is almost an exact opposite of the impedance graph and adding resistance tend to make the sound flatter(not taking damping into account).

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