Listening to music has always been among my favorite pastimes, and as a music enthusiast, I have always considered sound quality important. I have experienced using a Walkman, Discman, radio cassette player, compact disc player, iPod Nano, iPod Touch, iPhone, iPad, as well as streaming services like iTunes and Spotify to enjoy my favorite songs.
I am fond of classical music by the three B’s — Beethoven, Bach, Brahms, as well as Tchaikovsky and Handel’s The Hallelujah Chorus; jazz by Louis Coltrane and Diana Krall; ambient music; movie soundtracks; piano; Britpop music by The Culture Club, One Direction, and Annie Lennox; pop music by Rihanna, Usher, and Kanye West; calming operatic music by Charlotte Church and the Vienna Boys’ Choir; and instrumental music. I am certainly a music lover. In fact, I have 1,135 songs currently uploaded on my iPad.
You may wonder how I relish these sounds. Well, I use my Bose noise-canceling headphones and Sennheiser headphones at home. I chose to purchase these brands since I am after the top-notch music-listening experience these products offer.
The Bose noise-canceling headphones allow me to hear only my music and no other unwanted external sounds (like for example, people’s audible voices while they are engaged in conversations, motorized vehicles passing by, rain clattering on the rooftop, the neighbor’s barking dogs, and other distractions that can be considered mere noise pollution).
With the impedance level of my high-quality headphones properly designated for my audio equipment, I can enjoy whatever music I choose.
You may wonder what the technical term “impedance” means. If you are a music fan like me who considers enjoying music as an important component of life, or if you work for the music production industry, considering the impedance level of the headphones you are using is key.
Let me explain to you what impedance refers to by giving you ten facts about this headphones-related idea. But first, let’s talk about headphones. What are these devices?
Headphones are a type of sound equipment that contains one or two transducers or small speakers connected to a plastic or metal headband. The headband, which normally rests behind or above the user’s head, enables the correct placement of the transducers over the ear.
1. Impedance Levels Affect Headphone Performance.
The concept of impedance applies to electrical devices. A technical measurement, it refers to the amount of opposition to the current – whether alternating or direct – when it flows through a conductor component circuit.
If you purchase headphones, you can see the specifications on the box showing the device’s actual impedance. This information defines how the unit will operate with an audio system. Headphones come in different levels of impedance like 8, 16, and 32 ohms.
The impedance of headphones is usually created to get the desired volume intensity at a given voltage level. The higher the impedance level, the less current will flow.
Low-impedance enables headphones to capture more power from the amplifier. You can expect the sound to be louder. On the other hand, the sound is soft for high-impedance headphones. The higher voltage level is necessary from an amplifier to achieve a loud sound.
The impedance of headphones and audio sources should match in order to get the maximum usable power. When they are incompatible, loss of current or power can happen and should be avoided.
2. Impedance Levels of Headphones Are Measured in Ohms.
Ohm is the unit of measurement for impedance, indicated by the Greek sign Omega (Ω). The impedance levels of headphones range from 80 to 600 ohms or higher.
Approximately 20 to 40 ohms is a justified choice for typical music listeners. On the other hand, 64 ohms and above are for professionals in the music production sector.
3. High-Impedance Headphones and How They Operate
High-impedance headphones are very sensitive equipment. Highly audible sounds can be expected from their terminals.
Basically defined by an impedance rating of approximately 25 ohms and above, these types of equipment require more power to produce high audio levels. Because of this feature, they are safeguarded from damage which can be caused by overloading.
Most high-impedance headphones are quality headphones. Beyerdynamic and Sennheiser are two companies that only offer headphones under the high-impedance category.
Recording studios normally employ high-impedance headphones. These settings have several headphones wired in parallel, receiving an input signal from one source.
Headphones with high impedance are more electronically durable than their low-impedance counterparts. An example of equipment which has high-impedance are DJ headphones which normally range from 25 to 70 ohms.
4. Low-Impedance Headphones Are Louder and Require Less Power.
Headphones with low impedance have an estimated 25 ohms or less. They demand minimal power to deliver high audio levels. In addition, they are designed to be connected directly to a single audio source.
Headphones with low-impedance designs include a majority of on-ear, in-ear, and over-the-ear headphones.
They function best with equipment that has weak amplification. These are usually battery-powered portable devices such as cell phones, music players, and the likes.
5. Sound Quality Varies between High and Low-Impedance Headphones.
High-impedance headphones offer a more expressive and dynamic level of sound quality, adding new dimensions to the music you are listening to. The 250-ohm version sounds more natural, voluminous, and smoother than lower-ohm versions. This type of headphones is ideal for mixing and analyzing sounds at recording studios.
High-impedance headphones also produce clearer and more transparent sounds. Hissing sounds are displaced. Users can expect clean, more balanced, and less distorted sounds at louder levels as compared to the low-impedance models.
Plus, high-impedance headphones also offer better bass definition and more spacious soundstage. Apparently, high-impedance headphones keep the integrity of audio files better than low-impedance headphones do.
The sound coming from the latter, on the contrary, can get too tinny or bassy. Higher distortion levels on the sound also make manifest.
6. The Is an Important Determiner of Headphone Impedance.
The voice coil significantly determines impedance in headphones. This copper wire is available in different lengths and thickness. You can find the voice coils in the drivers of the headphones or the small speakers inside the earcups that produce the sound you hear. As they are winded, they are also coated to avoid the risk of short-circuiting.
The voice coil of 250 to 600-ohm high-impedance headphones is a light and very thin wire which measures just 0.018 millimeters. This scale is roughly half the thickness of human hair. The thinner wires have more layers on the voice coil.
The small diameter enables the wires to fit tighter, preventing air from penetrating the windings while facilitating the strength of the electromagnetic field. Hence, high-impedance headphone models have better levels of bass and offer decreased distortion, unlike their low-impedance counterparts.
On the other hand, low-impedance headphones possess heavier and thicker voice coils. These materials are said to have less resistance than a thin wire. Furthermore, they are easier to manufacture and are usually used for 32-ohm headphone models.
7. The Relationship between Impedance, Power Levels, and Loudness
For low-impedance headphones, you don’t need more power when you turn up the volume. Actually, there is low battery drainage for battery-operated portable equipment. Alternatively, high-impedance headphones demand high power levels if the volume is increased.
8. The Relationship between Impedance and Input Power
It is important for headphone users to ensure that the power supply of their audio source matches their headphones’ impedance.
Fine high-impedance headphones require higher input power to drive them. They don’t normally produce optimum results with MP3 players or iPods. Hence, they should not be plugged to a portable device which outputs a low voltage current.
If so, the high-impedance headphones will not play a loud sound at all and there will be reduced dynamics. They are expected to work best with high-voltage professional amplifiers.
On the other hand, portable, battery-operated music players should be connected to low-impedance headphones which have low power intensities and allow for higher volume levels. Dedicated headphone amplifiers are unnecessary for this equipment.
9. How Amplifiers Work with High and Low-Impedance Headphones
Headphone users normally encounter some issues with their headphones. This prevents them from taking full advantage of their equipment.
Among these problems are distorted audio, high sound level with the volume set at the minimum, and low sound intensity with the volume set at the maximum. Given these problems, finding the correct amplifier to connect to your headphones is important.
Tube headphone amplifiers are highly compatible and work perfectly with high-impedance headphones. The disadvantage of using high-impedance headphones though is that sound levels may be too low despite a maximum volume because there is lower output for the same voltage. Therefore, powerful external amplifiers are necessary to operate this type of headphones, in order for them to deliver the best sound quality.
On the other hand, it is highly suggested not to use powerful amplifiers with low-impedance headphones because of their low threshold limits. Low-impedance headphones are prone to damages like “blowouts”.
For instance, let’s say you connect an inexpensive headphone to a DJ mixer. Once the volume is turned up to the maximum level, the headphones will be blown out.
Most headphone amplifiers work best with various levels of impedance. Some of them offer at least three to four headphone jacks, each serving a different level of impedance.
10. Manufacturing Costs Significantly Impact Impedance Levels.
The cost to manufacture headphones has an impact on the impedance levels. Since more precision is required to produce high-impedance headphones with thinner voice coils, it is more expensive to make them.
German headphone manufacturers are inclined to choose high-impedance designs for their premium headphones. However, nowadays, users prefer the affordable but better quality low-impedance headphones for their portable audio players. This trend has been surging.
CONCLUSION & RECOMMENDATIONS
The impedance specification for headphones is usually disregarded by most headphone buyers. However, if you are after a superior listening experience with your headphones, it is important that you consider this important specification.
Doing extensive research about the headphones and the equipment you will be connecting them with, whether you will need low-impedance or high-impedance headphones for your music player or home amplifier, is also helpful. This will help you achieve the best sound quality for your music experience.