What Is Impedance in Headphones

Last Updated on by Chris Wilson

Are you rummaging for your new headphone set? If you are in the market for buying a new set of headphones, then you will discover that there are a plethora of options available, and the selection is enormous. Which set of headphones do you choose is ultimately your personal preference, but you must be wondering about the best way to make an informed decision. Apart from personal preferences, there is another crucial factor to take into account: headphone impedance!


If you don’t know what impedance is in headphones and what will be the right amount according to your need, then you are in the right place. You will be getting an insight into headphone impedance, which will enable you to invest in the right product.  

What is impedance?

Impedance is basically the electrical resistance that is usually expressed in units of ohms. You should know that a set of headphones with a specific impedance will need a certain output capacity from the connected amplifier. The amplifier then has to process that output capacity from the amplifier to make sure that the headphones deliver the optimal sound. It implies that the output impedance of any headphone’s amplifier needs to correspond with the impedance level.

Generally, it is a great idea to ensure that the headphone impedance is at least eight times more than the output impedance of the amplifier. For the sake of understanding, if the headphone’s impedance is somewhat 16 ohms, then it would be perfect to have a 2-ohm amplifier. This ratio, in technical terms, is known as the damping factor, which is headphone impedance divided by the amplifier’s output impedance.

You should bear in mind that if the difference is more than eight times, then you probably won’t hear it, and if it is less than that, then the headphone will not sound as good as it should. The resistance level of the headphone determines the output voltage of the amplifier that is required in order to generate a power of one milliwatt.

Headphone sensitivity

Manufacturers of both speakers and headphones indicate the sensitivity ratings of their products at 1 kHz for one milliwatt of power. However, the impedance of the speaker is usually measured at 1 watt, though very few headphones can handle such significant power. Moreover, the proximity of the headphones’ transducers with the ears of the listener ensures a relatively high sensitivity with only a few hundredths of milliwatts of power.

In order to measure the sensitivity of a headphone pair, the microphone is placed very close to the transducers instead of 1 meter away from them. You will be amazed to know that the microphone is often placed at the end of the artificial ear canal. Thus, the sensitivity is commonly established at between 90 and 120 dB approximately.

Which impedance level is better?

As discussed earlier, the higher the impedance of the headphone, the more output the amplifier of the device needs to generate. Usually, the headphones with low-ohm (approximately 16-50 ohms) are better suited for a battery-powered device like a smartphone, tablet, or an MP3 player. If the impedance is higher, then the overall volume level of the headphone will be comparatively low. For the ones who need headphones for their Hi-Fi set or to use in the studio, they are better off investing in a high-quality set with a high level of impedance.  

You might need to consider a few rules of thumb, which are:

  • In-ear headphones should be of 16-50 ohms.
  • Mobile applications will need 16-50 ohms as well.
  • Studies and Hi-Fi usage require 60 ohms or more.
  • DJs need an impedance of 60 ohms or more.

Headphones with high impedance

High impedance headphones will provide an optimal volume level when these are connected with an audio interface or a Hi-Fi amplifier, but unfortunately, not when connected to a smartphone, laptop, or tablet. If you already have a high impedance headphone, then you can efficiently resolve this problem by using a headphone amplifier. Though a more compact option is a Digital-to-Analogue Converter (DAC), and that will improve the audio quality as well. You need to make sure whether a DAC will be suitable and compatible with your device or not before investing your hard-earned money in one.

Bear in mind that these are troubleshooting solutions which are to be applied as a last resort, not as the first priority. If you are aiming to get the best results, then you need to invest in a set of headphones that have an impedance level that will best suit your device or equipment.

Does more impedance mean better performance?

With all the details that have been discussed, you might be excised to think that headphones will need an external amplification in order to sound better. This, however, doesn’t have anything to do with reality. In general, high impedance headphones are also used for another purpose, for example, DJ headphones. When you are working with a DJ deck, you need to plug in headphones in order to help them mic tracks live as the impedance output is quite high. If in this scenario, we have used a headphone set with 32 ohms, then it can easily be blown. Hence, a headphone with high impedance will be more useful at home, handling the power which is supplied to it while delivering an admirable audio performance.

Conclusion

You must have heard that exposure to knowledge will ultimately lead you to wisdom. After reading this blog, you will have enough knowledge to discern audiophiles. Now that you understand what impedance is and how it plays a crucial part in overall performance, you can make a better decision for your next purchase. No matter which headphone set you use, and for what purpose, all you need to ensure is that it has a compatible amount of amplification to deal with the headphone’s impedance accurately. So, be sure of getting your hands on the right set this time. 

Chris Wilson

Chris is one of the guys behind HeadphoneSelection.com. He is an Electronics Engineer by profession and he enjoys expressing his real-life experiences with technology and sharing it with others.

Click Here to Leave a Comment Below

Leave a Comment: