[senns&nonsense]

Does more impedance equate to better sound? How does it typically change the sound?

 

[nibiyabi]

Not necessarily. There are good and bad headphones that are both low and high impedance. As far as changing the sound, that's something I'll leave to the more qualified among us.

 

[feh1325]

usually adds more bass
if there's any hiss from your source, impedance can take that away

 

[Gurra1980]

impedance by itself doesn't change the sound, but using thinner and longer copperwire in the driver gives higher impedance and this can change the sound. As I understand it, this usually makes the magnets tronger and therefor makes the sound more controlled, a low impedance HP offten sound more "sloppy" or what to say, but this isn't nessesary the case, just look at grado, they have one of the fastest and most controlled drivers of all.

 

[ericj]

The impedance itself doesn't 'add bass'.

If your source has a capacitor-coupled output, and the capacitors are of insufficient size, the high-pass filter formed by the capacitor and the impedance of the headphone driver can lead to severe attenuation of the bass.

For example, my Sennheiser DSP Pro has 100uf on each output. If i were to plug 16ohm ER-6i's into them, this would result in about 3db of attenuation at 100hz, with attenuation increasing as the frequency decreases.

In laymans terms, this means that combining 16ohm 'phones with a stock DSP Pro results in No Real Bass At All.

 

[saint.panda]

Frequency is a function of impedance or vice versa. If the function is constant, there won't be much of a difference, just harder to drive (more power needed for the same volume), if it's not, there will be tonal changes depending on the impedance function. Check Headroom's grahps for that.

 

[ericj]

Quote:

Originally Posted by saint.panda /img/forum/go_quote.gif Frequency is a function of impedance or vice versa. If the function is constant, there won't be much of a difference, just harder to drive (more power needed for the same volume), if it's not, there will be tonal changes depending on the impedance function. Check Headroom's grahps for that.

Congratulations on the most confusing statement i've seen on head-fi so far.

I think what you're trying to say is that for any given load the impedance will often differ from frequency to frequency.

This is true especially for reactive, inductive, and capacitative loads, but isn't the whole story on frequency response.

Edit: it is, however, why they call it the "nominal" impedance.

How efficient the driver itself is for a given frequency plays a massive part in that, too.

Also, headroom's graphs are measured, not theoretical, so the shape of the earcup, any mechanical damping methods used in the earcup, and even the shape and material the earpads are made of all affect their curves.

But yeah, if you figure that two drivers have the same diapragms, same magnets, and just different impedance voice coils that are otherwise identical (weight, shape, etc), the voice coils themselves may have differing impedance curves.

But my supposition is that this is rarely, if ever the case.