So, you’re in the market for high-end headphones and you’ve been looking at different makes and models.
Apart from the usual specs like dB, type (closed or open back), etc, you’ve probably noticed that they also have an ohm rating.
But what does that mean? And why do the same models have multiple Ohm ratings?
Let’s go over what Ohms are, what the differences in Ohm ratings are, and how they impact the sound.
What is Impedance?
The first thing to know is what Ohms are. Basically, Ohms are the amount of impedance the headphones have.
Impedance is the resistance and reactivity to an electrical current present in the headphones. A low impedance, or low Ohms, means less resistance, and high Ohms means high resistance.
There are three levels of impedance:
Low Impedance – 16 – 32 Ohm. Headphones in this range work well with devices that have weak built-in amplifiers like phones, laptops, etc.
High Impedance – 100 Ohm and above. High impedance headphones require more power, usually from an external amp, to work properly and can even benefit from higher voltages.
Gray Area – 32 – 100 Ohm. Headphones in this range will require power according to their sensitivity rating. A high sensitivity, 91dB for example, will mean that the headphones will need more power.
How Does the Ohm Rating Affect Sound Quality?
Now that you have a better understanding of Ohm, let’s look at how it influences the sound.
A good example of the same headphone model having different Ohm ratings is the Beyerdynamic DT770. It comes in both 80 and 250 Ohm versions, so let’s use it as our reference.
At 80 Ohm, the headphones have more bass and less prominent treble. At higher volumes, 80 Ohm will produce even more bass.
The 250 Ohm version has a similar bass response but has more high-end to even the sound out more. It also has a bit more mid-bass and sub-bass roll-off.
What does this mean for your experience?
With its better bass output, the 80 Ohm version is better suited for listening for enjoyment. You’ll be getting more out of 80 Ohm while listening to music or gaming.
If you’re looking for headphones for studio work, the 250 Ohm pair will be better with its wider frequency response.
This is important for the critical listening involved with recording and mixing audio.
Amp and a DAC
While both 80 and 250 Ohm headphones will benefit from an amp, you’ll be able to get a lot more out of the 250 Ohm version with one. I’d recommend getting an amp for 250 Ohm headphones.
DACs (Digital to Analog Converter) are present in basically every device that plays audio. Your phone, laptop, iPad, they all have built-in DACs.
The DAC or soundcard in your device might not be powerful enough, however. In that case, you’ll need to get an external one.
If the headphones aren’t loud enough, the audio crackles or there’s noise, or the overall quality is just bad, then you’ll definitely need a DAC.
Something like the Fiio E10K is a great budget combo amp/DAC.
If you’re just looking for good gaming or general listening, then 80 Ohm headphones are the way to go.
For the serious audio engineer or self-recording musician, 250 Ohm headphones are hands down better.