[JustinBieber]

I'm asking this question here for a dude on another forum. A big thanks in advance to anyone who reads over or helps! 

 

 If I purchase a 3.5mm male-to-female cable to extend my headphones' cable, will this alter the output impedance seen by the headphones? I need a high damping factor, and don't want to override my amp with a very high impedance "device" like a cable... I think it's a "no the cable does nothing" because the cable doesn't do anything but transfer signal, but I'm not sure.

 

[MindsMirror]

In an ideal world, all cables and connections would have zero resistance and would do nothing but transfer the signal. In reality that is not the case. The cables (extension cable and the stock cable on the headphone) have some resistance, and you can consider that resistance as being added to the amplifier's output impedance.

 

[SilverEars]

  In an ideal world, all cables and connections would have zero resistance and would do nothing but transfer the signal. In reality that is not the case. The cables (extension cable and the stock cable on the headphone) have some resistance, and you can consider that resistance as being added to the amplifier's output impedance.

True, but at the same time there are additional factors to be considered for practicality.  What should be considered is the cable's resistance relative to the headphone's.  If the headphones have significant impedances(8X the cable's or more), there really should not be much decernable changes to the output from the source.  This is based on the output impedance of the source being 0.  Cans will typically have too large of an impedance for cable's impedance value to matter, but iems, the specs and if impedance graph is available should be looked at.  The impedance graph shows where the impedance dips very low.  Some iems such as SE846, the impedance dips as low as 4ohms, which is getting very close to a iphone 5 output impedance of 4ohms or a cable with 1-2ohms.  
 
First the output impedance of the source and headphones should be checked.  Then compare that value to a typical cable's impedance which is like 1-2ohms, and if it's significant, relative to the headphone's impedance, than it should be checked if audibly the impedance is affecting the sound.  Sometimes, iems maybe bright, and the impedance of the iem can dip at the treble region very low like 7ohms, and if the DAP has 3 or so ohms, this can possibly be have better outcome for the listener if the listen think the iems were to bright.  
 
So in the end, the rule is check to see if the sum of the impedance of the digital audio player and the cable are significant enough relative to the headphone's impedance, in the ball park of being 1/8th of the headphone's lowest impedance point on the impedance characteristic graph.  If it's greater that 1/8 or so, and audibly not favorable, look for another source or use an external amp as a buffer to reduce the output impedance.

 

[castleofargh]

  I'm asking this question here for a dude on another forum. A big thanks in advance to anyone who reads over or helps! 

 

 If I purchase a 3.5mm male-to-female cable to extend my headphones' cable, will this alter the output impedance seen by the headphones? I need a high damping factor, and don't want to override my amp with a very high impedance "device" like a cable... I think it's a "no the cable does nothing" because the cable doesn't do anything but transfer signal, but I'm not sure.

you can't answer a general question like that, what is the headphone impedance and most of all what is the headphone impedance response curve? what is the amp impedance output? how long is that extention supposed to be?

 

[JustinBieber]

Well, that was all the info he posted. I'm not sure what cans he is using or any info on his source. He just replied to me:

His answer got me digging... The resistance of 22AWG copper is 52.96ohm/km, so a 3ft run has a resistance of 0.048ohm or a 6ft run has a resistance of 0.09ohm which is too little for me to care about.

 

[JustinBieber]

Update: Here is the source info.

 Amp -> Objective 2 IEMs -> Noble Audio 3U, ~this

It seems like it would be fine to me.

 

[SilverEars]

  Update: Here is the source info.
It seems like it would be fine to me.

Awsome, it's nice you provided Rin's blog too as it contains the impedance characteristic.  I would say, worry about the DAP or Amp's output impedance than the cable's.  The figures you guys put out is way to low to have any affect.  With raised output impedance of the DAP or Amp, you will lose some bass so strive for 0-2ohms output impedance device.

 

[PDVJAM]

And what's the difference for the end listener, what the output impedance of the player - 0 or 2-3 ohms?

 

[castleofargh]

MRO shows it all. your buddy will not have any problem as long as he uses a simple basic extension cable and not some metascience stuff. I use the extention cable from an old Q-jays that is about 90cm( 35inches?) between the O2 and any IEM I use. it doesn't alter the signature of my customs(when adding resistors does).