[xtroria]

So I just measured the output impedance of my One plus one and it resulted in approximately 3 ohm output impedance. I'm not entirely sure about this result since I did it in a bit of a ghetto way.
 
For daily use, i generally connect it to my Westone 4R which has this kind of impedance swing
 

 
Its lowest the impedance is probably around 18 ohm and the ratio between output impedance and the impedance itself is 6:1
 
Innerfidelity recommends a minimum ratio of 10:1 while NWAvguy recommends 8:1
 
Do you think the sound different would be big enough through calculation itself that it'd be audible?

 

[MindsMirror]

The minimum and maximum impedance of the headphone is about 18 and 48 ohms. That means the driver will receive from 85.7% to 94.1% of the total voltage depending on the frequency, which will vary the frequency response by up to 0.81dB. That is enough to be audible, but you probably won't notice unless you do a direct comparison with an amp with much lower output impedance.

 

[castleofargh]

I get the same as @MindsMirror if we count an almost zero ohm source in comparison, and already only about 0.5db compared to a 1ohm source. so it's not what I would call a problem.
also the W4 is a special IEM because if you look at the FR, you see that those changes from a higher impedance source tend to boost the recessed mids a little.
it depends on taste obviously, but I'm one of those who find the w4 to sound "nicer" on a higher impedance source.

 

[xtroria]

  I get the same as @MindsMirror if we count an almost zero ohm source in comparison, and already only about 0.5db compared to a 1ohm source. so it's not what I would call a problem.
also the W4 is a special IEM because if you look at the FR, you see that those changes from a higher impedance source tend to boost the recessed mids a little.
it depends on taste obviously, but I'm one of those who find the w4 to sound "nicer" on a higher impedance source.

I get an impression that I get more bass on my O2 compared through my phone, although I havent done ABX test for it. 
 
What formula or coverter did you use btw?

 

[Steve Eddy]

I get an impression that I get more bass on my O2 compared through my phone, although I havent done ABX test for it. 

What formula or coverter did you use btw?

Don't need an ABX. Just a frequency response sweep.

se