Beyerdynamic Ohm-age sound difference?

[Maru777]

I'm in the market for Beyerdynamic headphones, but cannot decide on the impedance (32, 250 or 600 Ohms). I will be using the headphones on a desktop, so getting an appropriate amp and/or equipment should not be an issue. I will not be using them for portable devices. I read that higher/lower impedance does not directly impact sound quality, but it can effect some things like the "prominence of the bass" or "the treble" depending on what Ohm-age you are using. This might be due to different drivers though.

Does anyone know the subtle differences in the characteristics of sound across the different Ohm-ages (if any)?

Thanks!

 

[i7Baby]

If your getting a sound card/amp, then it needs to match the output impedance spec for that.

 

[InvalidError]

The need to match impedances is mostly a studio thing where cable runs can be hundreds of meters long and known quantities at both ends make life much more convenient.

If the headphones have a flat 32 ohms or 600 ohms impedance across its whole frequency range, it will behave exactly the same with any amplifier with flat gain and output impedance of any value, give or take the attenuation from the voltage-dividing network between the two impedances.

If the headphones' impedance is not flat, there is not much the amplifier can do to change that. You need an equalizer to flatten it out regardless of impedances as well.

 

[Maru777]

Ah, so it seems Ohm-age exists to make studio equipment management easier rather than being something that impacts the sound itself...

 

[InvalidError]

Ah, so it seems Ohm-age exists to make studio equipment management easier rather than being something that impacts the sound itself...

The other traditional reason for matching in audio/RF equipment is maximum power transfer: when you have a fixed source impedance, you get the most power out of it by matching its output impedance. Those impedances are usually dictated by the cable impedance between devices to minimize signal reflections on long cables.

Impedance matching only works on sources that are designed to work that way. With low-impedance sources, you already have more power than you need long before matching the source's impedance and the source will usually start clipping due to hitting its current or power limit if you attempt to go anywhere near that far.

If you absolutely want to match a low-impedance amplifier with your high-impedance headphones, all you need to do is add resistors that match the difference in series between the two at the amplifier end of the wires. You lose about half the voltage and three quarters of your power this way though - compared to connecting directly to the low-Z amplifier.