It’s easy to confuse the benefits of active noise cancelling, ANC for short, with passive isolation when it comes to headphones and earphones. This is easily done, as essentially they are both doing something similar, but in very different ways. Because of this, you may want to make sure you choose the right headphones for your needs.
Active vs. Passive noise isolation:
ANC and passive noise isolation differ significantly in how they block out unwanted outside noise. One uses an electronic circuit and sound waves versus a purely mechanical system without any additional sound trickery or power required. Their goal is the same: to allow you to enjoy your music without any distractions.
Passive isolation:
Passive isolation is a term used for headphones and earphones that block out external noise and reduce the amount of sound leaking for others to hear without using power. This is achieved through their design and the materials used. Most closed-back headphones or in-ear isolating earphones, which fit in the ear and typically use eartips to create a seal, do this very well, and some do it better than others. Many earphones and headphones have venting on them to help tune the sound signature, and these vents often compromise the sound isolation of the model. This is primarily observed in models that utilize conventional dynamic drivers. Balanced armature models are easier to seal fully, and they typically don’t require venting. Some, such as models from Etymotic, offer extremely high levels of passive isolation.
Lots of things can improve isolation, such as:
- Leather earpads
- A good in-ear fit
- Heavy clamping force or a tight fit on the head
- Acoustic treatment, such as dampening in the earcups
- The shape and material of the driver housing
Etymotic claims that their ER series of earphones offers between 35 and 24 decibels of attenuation. Attenuation is the amount of sound that is blocked. Depending on the ear tips and depth of the insertion, this is much higher than most earphones. The Westone Pro X series of earphones offers up to around 25 decibels of attenuation, and some studio headphones, such as the Sennheiser HD380 Pro, provide up to 32 decibels of attenuation. On the other hand, most closed-back headphones will likely provide around 20 decibels.
Active noise cancellation:
ANC, on the other hand, is a very different approach to blocking out noise. ANC uses external microphones to monitor external noise levels and create a phase-inverted sound wave to cancel out the ambient noise before it reaches your ears. Clever stuff. This system requires a power source, so it will only function if power is supplied, typically with a rechargeable internal battery. ANC is best used in environments where there is persistent low mid-frequency noise, as this is where the technology works best. This is why they often work well in environments with constant background noise, such as on planes and public transport.
What ANC doesn’t do is cancel out all noise, especially impulse noises like sirens and roadwork. It also tends not to cancel out higher-frequency noise.
To decide which is best for you, let’s go through the pros and cons:
Pros and Cons:
- Sound passive isolation will do a great job of cutting out most noise across the whole frequency range. It does lack effectiveness in the lower frequencies, though.
- ANC performs exceptionally well on lower frequencies. Where they struggle is with higher frequencies.
- A significant benefit of passive isolation is that it doesn’t require power, so there’s no need to charge your headphones for it to function correctly.
- As for wireless headphones and earphones, those that don’t offer ANC tend to have a much larger battery life. So, if extended listening is a priority, you may want to focus on passive isolation rather than ANC.
Effect on sound quality: ANC tends to affect the sound quality. Now, this can be a good thing or a bad thing, depending on your taste. For the audio purists out there, you may find that ANC ruins the sound as it tends to add bass when activated, which can sometimes come across as a bit bloated or compressed. There will be those of you who love bass, so that ANC will enhance your headphones’ sound even further. This is worth considering, though, because if audio is your main priority, you might find that you get a lot more for your money when you avoid ANC.
Wind noise: Another thing to consider is wind noise. When ANC is active, wind blowing past these microphones can create a loud noise. It can create a loud noise while listening. Some headphones deal with this better than others, so make sure to look into this. And if you use your headphones in a windy environment, then you may want to consider focusing on passive isolation over ANC, as wind noise won’t be an issue there.
ANC Headphones: Value vs. Compromise:
When buying ANC headphones or earphones, a significant portion of the cost is allocated to the ANC technology. Knowing what you prioritize will help you choose the best value model for your needs. If you know you want ANC, perhaps you travel a lot or prefer the effect. Then, unless you’re willing to pay for the most expensive models, there will be a compromise in terms of sound quality or battery life, resulting in a lower value. As the models that don’t offer ANC tend to put more focus on the sound and battery life for wireless products, this can be achieved at a lower price.
Conclusion:
There are models out there that offer ANC that may not be as good as the competition. However, they have chosen to put more focus on passive isolation, audio quality, or battery life. Therefore, it is good to take a balanced look at what you buy to make sure the overall benefits suit your needs.
We wouldn’t recommend buying a headphone with amazing ANC and mediocre audio or battery life if you primarily use it for listening and traveling, or if you mainly listen to music and travel without much need to travel. That’s just one example, and if you’re not sure or need more advice, then please do get in touch; we’ll be happy to help.
I hope you enjoyed this guide on ANC vs passive isolation. Please feel free to leave a comment below.