[Phredd]

I've got the Sennheiser HD598 which I modified to accept the Momentum iPhone cable. It still sounds great, but I don't know if there's a subtle loss of sound quality that I might notice with certain music. I think I notice a slight volume attenuation. The stock HD598 cable is much thicker than the Momentum cable. The HD598 impedance is 50 ohms compared to the Momentum's 18 ohms, so does the HD598 require a higher gauge cable? Is there a way to measure the resistance of the cable? I assume it needs to be measured with the headphone connected...

 

[Phredd]

Anyone? Is this the right forum to ask this?

 

[jaddie]

  I've got the Sennheiser HD598 which I modified to accept the Momentum iPhone cable. It still sounds great, but I don't know if there's a subtle loss of sound quality that I might notice with certain music. I think I notice a slight volume attenuation. The stock HD598 cable is much thicker than the Momentum cable. The HD598 impedance is 50 ohms compared to the Momentum's 18 ohms, so does the HD598 require a higher gauge cable? Is there a way to measure the resistance of the cable? I assume it needs to be measured with the headphone connected...

 
You can measure the resistance of the cable with an ohm meter capable of low-ohms measurements. The resistance of a 3' headphone cable will be a fraction of an ohm. You don't need the headphones attached.
 
The higher impedance headphones could get away with smaller cable. 
 
It's unlikely either cable is making an audible difference unless the small cable is very, very small.  
 
You'd have gotten a faster response in the Sound Science sub-forum.

 

[scottosan]

Its not just a matter of resistance. It's also about cable capacitance and inductance.High impedance lines are more adversely affected by the inherent capacitance that is present in the cable itself. This capacitance combines with the impedances of the source and destination to set up a filter, as the impedance increases and/or the capacitance per foot increases.  Essentially, the more the effect is the rolling off of some of the highs.

 

[jaddie]

  Its not just a matter of resistance. It's also about cable capacitance and inductance.High impedance lines are more adversely affected by the inherent capacitance that is present in the cable itself. This capacitance combines with the impedances of the source and destination to set up a filter, as the impedance increases and/or the capacitance per foot increases.  Essentially, the more the effect is the rolling off of some of the highs.

 
Well, true in the absolute, but we're talking headphones and headphone amps here, so 50 ohms completely swamps out all capacitance in the cable, but the amp output which is certainly no higher than a few ohms is what really does it.  You can completely ignore cable C and the resulting filter in all cases of headphones, headphone amps, speakers and speaker amps, as well as inductance.   The only factor, and it's extremely slight, is wire resistance. In the case of 50 ohm phones, it would have to be ridiculously high (for wire) to make any difference.  It's a resistive voltage divider, and even if the wire were a couple of ohms (pretty much impossible, by the way), it would result in just over 1/4dB of loss...inaudible.

 

[Phredd]

Thanks, guys. Sounds like the cable isn't that critical in my situation. Maybe I should meander over to the Sound Science forum to learn more. I know that people spend $hundreds on cables, so I'm a little baffled. I wonder why Sennheiser uses different thickness cables if it doesn't matter. But it sounds like I don't need to worry about using the thinner Momentum cable on the HD598, which is good since it's a good iPhone remote.

 

[jaddie]

I wonder why Sennheiser uses different thickness cables if it doesn't matter. 

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