Speakers and headphones are commonly measured in impedance, which is more esoteric than other specifications like voltage or amperage. This confusion is only amplified when you consider that both high and low impedance audio output devices are created. So is high or low impedance better?
High impedance is better because it delivers superior sound quality. However, low impedance equipment is more suitable for casual listening on phones or laptops. High impedance equipment is geared towards professional use or audiophiles because they require bulky special equipment.
In this article, I’ll be going over how impedance works, affects your listening experience, and the differences between low and high impedance in audio output devices.
What Is Impedance?
Impedance is the measurement of resistance to electrical current that produces voltage, as per Ohm’s Law. It measures how much power can be sent from a source to an output device and affects how much power is needed to power the output device adequately.
Ohm’s Law is complicated and getting into the details would go beyond the scope of this article. Here is a good introduction to Ohm’s Law. For now, what you need to know is that impedance affects an output device’s sound.
How Does Impedance Affect Sound?
Impedance is most commonly used in ohms (Ω) to determine whether an audio output device is a ‘high’ or ‘low’ impedance. There isn’t an exact limit, but most headphones under 50 ohms are considered to be low impedance.
Broadly speaking, impedance mainly affects sound by determining how much power it needs from the music player or amplifier to play audio at a decent volume.
What this means is that 25-ohm headphones will sound fine through a phone or computer jack. If you try to use 600-ohm headphones, you would barely hear anything at all. With the proper amplifier, the sound on those 600-ohm headphones would be far superior to the 25-ohm headphones, but what matters the most is the source.
Is High or Low Impedance Better for Sound Quality?
In terms of sound quality, high impedance is technically better, but that shouldn’t be the primary consideration when choosing headphones or speakers. High and low impedance is primarily used to advertise what power sources are suitable for use with them.
The needs of someone listening at home are very different from a professional DJ or music producer. Your laptop or phone could probably support 25-32ohm headphones, but not much higher.
In professional settings such as music producing, high impedance in headphones helps them to not blow out when plugged into professional music equipment that has multiple devices plugged in at once. They also produce louder, more crisp, and polished sound experiences than low-impedance headphones.
Most commercial headphones can be played on smartphones or laptops, and don’t need a special external amplifier. The rise of audiophilia in recent years has made higher-quality headphones, amplifiers, and other audio equipment available.
So while low-impedance headphones are fine for casual listening, professionals and audiophiles are the ones going for the headphones with ratings like 250 ohms and above. The average person doesn’t have special external amplifiers and other systems capable of running those headphones, and that’s fine. Everyone has different needs.
Mobility is another crucial consideration when it comes to busy and mobile listeners. Wireless headphones can’t be plugged into external amplifier systems, not to mention not everyone enjoys the over-the-ear headphone design most commonly used for high impedance headphones. Sometimes we just want something light, easy, and functional for on-the-go listening, and that’s where low impedance shines the most.
One of the most important interactions that deal with impedance is ‘impedance matching.’ This is, at a basic level, just making sure that the output device is receiving enough power to perform to its full potential, but without too much power that could cause damage.
Ideally, you want the impedance of the output device to be somewhat higher than that of the source, otherwise undesirable characteristics could emerge in the sound. Things like unwanted boomy distortion, other distortion, and excessive volume can occur when you don’t match the impedance of an output device with the sound source.
Let’s say you plug a pair of 600ohm studio headphones into an ordinary laptop without an external amplifier. Most likely, they simply wouldn’t work or would play very quietly, and that’s because the computer can’t output the voltage the headphones need to play at an optimal level.
On the other hand, if you plug low impedance headphones into, say, professional mixing equipment that is designed for use with high impedance equipment, they’d most likely blow out and stop working. High impedance equipment is more resistant to being damaged by excessive voltage and ‘blowouts.’
Improper impedance matching, in either case, doesn’t get the desired results, but it’s more important to make sure you don’t blow out your low impedance equipment with too much power. You can always buy an amplifier, but buying new headphones can get very expensive.
Impedance matching is one of the reasons you should always endeavor to test new headphones on your actual sound source if possible because test equipment likely won’t match the specifications of your setup and will make the headphones sound different. This can lead to bad first impressions when they sound worse or different on your own equipment.
Check out my other article on What Does Distortion Actually Do to a Sound Wave?
How To Choose the Right Headphones for You
While low or high impedance should be an important variable when deciding what you’re looking for in new headphones, it’s worth noting what else you’re looking for in headphones. Other than impedance, multiple other factors go into choosing the best equipment for your ideal listening experience.
Over-the-ear? In-ear? On-ear? Everyone has their favorite ear design for headphones and their least favorites for different reasons. Some people like over-the-ear for maximum audio goodness, and others like in-ear so they can hear their surroundings. On-ear headphones are a good compromise between those, allowing for high quality while allowing the outside world to filter in.
Most high-impedance headphones you’ll see are going to be over-the-ear, though some exceptions like these SEAHF High Impedance 150ohm In-Ear Earbuds (available on Amazon) exist. Over-the-ear headphones deliver more bass with their greater surface area than in-ear headphones are capable of. High-impedance earbuds like the SEAHF 150ohm are commonly advertised with ‘bass boost’ properties for the same reason.
- Seahf High Impedance In-Ear Earphone has the real impedance without any extra resistance .High Impedance can provide a wide sound field ,good low frequency and a clear sound.
- The Special driving principle make the high impedance earphone is easy to drive.It can be drove in our cellphone ,make it more portable ,you can take it and enjoy your music without extra player.
- earbuds with handmade twisted wire for a better bass response and unparalleled audio fidelity. This is how a headphone should be, Classic and luxury. earphones operates within the best scientifically proven frequency response curve,which not only protect your ears but also provide the most pleasant listening experience.
Last update on 2022-06-25 / Affiliate links / Images from Amazon Product Advertising API
With low impedance equipment, you have a wider selection. Every conceivable piece of listening gear is available in low-impedance forms at very cheap prices. High impedance gear is more expensive to manufacture and so can’t match the price.
Wired or Wireless
Whether you want a wired or wireless listening experience will also drastically affect your buying decisions. Bluetooth or wireless headphones are generally low-impedance, being incapable of being used with external amplifiers. This is why the really top-end headphones are always going to be wired, to be used with external amplifiers and other audio systems.
On the other hand, some people are willing to sacrifice audio quality for the sheer convenience of not having to worry about tangling cords.
If you want high-impedance headphones, you’re most likely looking at a wired pair that will have to be used at home. Most wireless pairs won’t be capable of the same level of performance, so you’ll have to decide what you’re looking for.
While high impedance generally sounds better than low impedance in headphones, it’s more important to consider whether the device will be used with specialized equipment in a fixed setting, or for more casual listening at home or while out and about. Impedance is only one of a variety of important variables to think about in such a situation.
- CNet: Headphone buyers: Here’s what you need to know about low- vs. high-impedance models
- Harvey Mudd College: Impedance and Generalized Ohm’s Law
- My New Microphone: The Complete Guide To Understanding Headphone Impedance
- Turntable Lab: Headphone Buying Guide: What Is Impedance?
- Ear Rockers: Do High Impedance Headphones Sound Better?