[roflcopter159]

Hey Head-Fi,
 
I'm somewhat new to this whole world of audio quality (only started into it about 6 months ago) and one of the things I have never really understood is what sort of effect different resistance levels would have on the sound quality a pair of headphones would produce. So, if I had (for example) three pairs of DT990s side by side, each with a different resistance level (32, 250 and 600 ohms) would one sound better than the other? This question is based on the assumption that they are all properly amplified and on the same exact equipment listening to the same exact thing. 

 

[KG Jag]

In general the version of the can with the highest Ohm rating sounds better under the conditions you described.  This will give you more detail in the context of the DT 880, a sibling can of the DT 990.
 
http://www.innerfidelity.com/content/comparison-beyerdynamic-dt-880-32-ohm-dt-880-250-ohm-and-dt-880-600-ohm-headphones

 

[roflcopter159]

Hmm, very interesting read. Thank you for posting it. In the comments section one reader (sgrossklass) posted an argument to the experiment one point of which was calling out the possibility of some results based on the placebo effect. To this Tyll responded:
 
Quote:

 I'd say hearing the differences between the two higher impedance cans more likely a placebo effect thing. The 32ohm can was pretty obviously worse sounding.

 
So here is my question. If it is likely that the differences between the 250 and 600 ohm versions are based on placebo effect, would that be the case for all headphones of higher impedance (250-600 ohms)? Also, how would something like the HE-400 fit in when it only has a 35 ohm impedance? On something liked so much I would have expected a higher impedance somewhere in the 250-600 ohm range.

 

[KG Jag]

First--unless you compare different Ohm versions of the same model can (or at least those models that have the same drivers), you have an apples to oranges problem.
 
That is especially true when you compare dynamic cans (like the DT 990) to planar cans (like the HE-400).  The way they are designed and work is completely different.

 

[roflcopter159]

  First--unless you compare different Ohm versions of the same model can (or at least those models that have the same drivers), you have an apples to oranges problem.
 
That is especially true when you compare dynamic cans (like the DT 990) to planar cans (like the HE-400).  The way they are designed and work is completely different.

Ok. Thank you for helping me understand this better. 

 

[KG Jag]

 

  First--unless you compare different Ohm versions of the same model can (or at least those models that have the same drivers), you have an apples to oranges problem.
 
That is especially true when you compare dynamic cans (like the DT 990) to planar cans (like the HE-400).  The way they are designed and work is completely different.

Ok. Thank you for helping me understand this better. 

Glad to help.
 
I forgot to mention that I have a 250 & 600 Ohm versions of the DT 880.  The 600 Ohm version sounds better.  It cleans up the sound of the also excellent 250 Ohm version, especially with the highs.  However, the difference is much less than that between the 32 Ohm version and the 250 Ohm version.  Of course when your equipment will not properly drive the higher Ohm versions, the equation is entirely different.  You need a decent amp of some power to get what the 600 Ohm DT 880 has to offer.

 

[ferday]

the higher impedance can will have more turns in the coil, and combine that with it being an easier load to drive for the amp, this could potentially produce lower THD (distortion) and offer better control over the coil movement (likely most noticeable in the bass, although tyall's square wave shows that as well).  combining a high output (amp) impedance with a low impedance headphone is a recipe for distortion and poor control (and possibly even FR changes) so don't use your OTL tube amp with 32ohm cans and expect good things.  
 
i personally believe that with modern headphones and amps, all of these difference are not audible and therefore more likely placebo (not slamming those who hear changes, just that i don't!).  but if you hear the difference, by all means the higher impedances can theoretically sound better...just make sure you amp them properly

 

[roflcopter159]

Glad to help.
 
I forgot to mention that I have a 250 & 600 Ohm versions of the DT 880.  The 600 Ohm version sounds better.  It cleans up the sound of the also excellent 250 Ohm version, especially with the highs.  However, the difference is much less than that between the 32 Ohm version and the 250 Ohm version.  Of course when your equipment will not properly drive the higher Ohm versions, the equation is entirely different.  You need a decent amp of some power to get what the 600 Ohm DT 880 has to offer.

 
 

  the higher impedance can will have more turns in the coil, and combine that with it being an easier load to drive for the amp, this could potentially produce lower THD (distortion) and offer better control over the coil movement (likely most noticeable in the bass, although tyall's square wave shows that as well).  combining a high output (amp) impedance with a low impedance headphone is a recipe for distortion and poor control (and possibly even FR changes) so don't use your OTL tube amp with 32ohm cans and expect good things.  
 
i personally believe that with modern headphones and amps, all of these difference are not audible and therefore more likely placebo (not slamming those who hear changes, just that i don't!).  but if you hear the difference, by all means the higher impedances can theoretically sound better...just make sure you amp them properly

 
Ok, thanks for the info guys. It has been pretty helpful in understanding all of this so once again, thank you.