Difference between Headphone Sensitivity and Impedance

Whether you like to enjoy your favorite music, prefer listening to a podcast, or simply want to block out the hustle and bustle of everyday life through noise cancellation, it’s important to have a pair of quality headphones in your life.

We live in the age of technology where there are many options to explore, and sometimes the various technical terms can get confusing, but in this article we will discover the difference between headphone sensitivity and impedance and what you should be looking out for when purchasing your next set of headphones.

What is headphone impedance?

This can sound like a tough term to digest, but when broken down, it is really quite simple. Impedance is defined as electrical resistance, which means it’s basically how well your headphones can resist the electrical current passing through it. This is measured in ohms (Ω) and indicates how much strength your headphones will require to reach a comfortable listening volume. The higher amount of ohms, the more force and function your headphones can produce.

Certain gadgets such as smartphones may be unable to supply adequate power, meaning that even if you are at max volume, the sound quality may still be a bit weak, and you might even hear some strange distortions in the audio. This is why being aware of impedance when purchasing headphones is so important. It is considered that impedances of 20-40 ohms are a good choice for casual music listeners (such as the Phiaton BT 390 headphones) and 64 or higher for audiophiles. Anything above that will typically require a portable headphone amplifier.

What is headphone sensitivity?

The concept of sensitivity is similar to impedance, in that it measures the crispness of sound in your desired listening device, however it’s not particularly useful when determining whether or not to buy headphones. The problem is, many manufacturers aren’t always consistent with how it is measured. The sensitivity of a pair of headphones refers to how well it translates an electrical signal into an auditory signal, and it also determines how loud they will be at a certain volume level from the device. Decibels of Sound Pressure Level per Milliwatt, or dB SPL/mW, is the unit of measurement.

Since headphone sensitivity measures volume at a certain strength, it is also important to check it in decibels. For example, the sound sensitivity of a car passing you at 65mph around 25 feet away is 75dB, which is considered on the lower end of the scale but can still be “annoyingly loud to some people,” according to Iac Acoustics. Also revealed by Iac Acoustics is that 110dB is similar to live rock music, and is about the average human pain threshold, and music this loud should only be listened to for around 15 minutes. The safe range for sensitivity of a headphone is reported to be between 75 dB to 110 dB, however, individuals should use personal judgment as to not damage their eardrums.

So what’s the difference?

Most headphone and earphone specifications show actual impedance and sensitivity. Most headphones will have about the same range for sensitivity but it is worth knowing about the levels in measurement because if you are connecting to a smartphone, sensitive headphones will be able to play the music at a decent volume level. The higher the sensitivity, the louder the headphones are, but you’ll most likely be happy as long as you use your headphones at a safe volume.

As for impedance, being aware of this when searching for a new pair of headphones will come in handy as it will help us determine which audio sources will best suit the headphones for optimal performance. It would not be a travesty to purchase headphones with incompatible impedance, a headphone with an impedance that is either too high or too low for your desired music playing device may not provide the finest sound quality. Smartphones require lower impedance whereas professional music playing equipment will sound better with a higher impedance.

By Claire Barnett

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