[GlorytheWiz825]

Hi guys,

Okay, I'm somewhat confused on how impedance works in a pair of headphones. How does impedance help the sound quality for a pair of headphones? For example, a HD650 with its 600 ohm impedance takes a lot of voltage to drive, and thus we need to crank up the volume control knob on our source/amp. Whereas a Grado GS100 has a mere 32 ohm impedance, and takes more current to drive. So my question is...how does impedance affect the sound quality of headphones?

Thanks for all who provide answers!

 

[JaZZ]

Impedance has no direct correlation with sound quality. But solid-states amps with sufficient output voltage capabilities will benefit from higher load impedances in the form of clearly lower distortion (which in the individual case may be academic, though), and tube amps, especially if transformerless (OTL), like high impedances much better. The higher damping factor provided by higher impedances may also be positive, not just in the latter case -- depending on the amp.

Portable, battery-powered equipment is thankful for lower impedances. Unfortunately 80% of them suffer from partly dramatic bass drop-off with load impedances below 100 ohms (due to undersized buffer capacitors).
.

 

[DDRRE]

Quote:

Originally Posted by JaZZ Portable, battery-powered equipment is thankful for lower impedances. Unfortunately 80% of them suffer from partly dramatic bass drop-off with load impedances below 100 ohms (due to undersized buffer capacitors). .

Which is why 70% of them include a dedicated bass boost feature seperated from the optional preset equalizer.

 

[danielghofrani]

I am in school for electrical and computer engineering, the prof said imedance of a device is the vecor sum of the reactance and resistance.
basically impedance in AC is analogous to resistance in DC.
however I am not sure about its effect on audio quality. apparently studio headphones usually have higher impedances.
I heard from a not-very-reliable source that higher impedance headphones have a lower noise floor due to their low sensitivity, however he did not bring any scientific/engineering evidence to back it up.
I hope that helps.