What is headphone impedance and what does resistance affect?

When choosing headphones, the buyer wants to get a device with clear and pleasant sound. But for this, before purchasing, they study all the parameters. The impedance of the headphones plays an important role - this is an indicator of the total input impedance of the gadget. The user will have to learn how the operation of an entire acoustic system depends on the resistance indicator, what it affects, what value the impedance should have depending on the characteristics of the sound source.

What is headphone impedance in simple words

In practical terms, impedance is the total resistance measured at the gadget's input. This definition is given by Wikipedia.

Each acoustic device, as well as a smartphone, a computer with built-in speakers, and a home theater system, has an amplifier at the output. It generates fluctuations in the output voltage. They cause the speakers to emit output waves. For different types of devices, the output voltage indicators differ. Headphones are connected to this technique. For normal operation, they must have a specific value of reactive and active resistance for various frequencies. Impedance is the average of a combination of these numbers.

Whether a person listens to vocals or instrumental music, or uses wireless models for sports, modern headphones adjust to the required volume due to impedance. It affects their sensitivity, and therefore their volume.

Maximum power

You can also find this characteristic in the description of the headphones. But it is very ambiguous and can be interpreted in different ways:

maximum power at which the sound is not distorted,
maximum power at which the headphone elements (membrane, coil, etc.) will not be damaged,
analogue of sound signal power.

That is, this is an uninformative characteristic by which one cannot judge the volume of headphones, for example.

What is the difference between resistance and impedance

The term “impedance” is not used as a synonym for the term “resistance”. These are different concepts. The resistance of the device, which is indicated in the technical documentation, is active resistance (or resistive). While impedance is the combination of active and reactive resistance (also called total).

Manufacturers, as a rule, do not indicate the value of this indicator in the documentation. Impedance must be measured separately.

What does headphone impedance affect?

The magnitude of the impedance is reflected primarily in the sensitivity of the headphones. Users believe that sensitivity equals volume. If we are talking about speakers for a PC, then this approach is justified, because the resistance is either 4 or 8 ohms. The power of the amplifier is indicated accordingly, and the relationship between these indicators is visible.

But headphones are a device that has a number of technical features and a large range of resistance values. The relationship between the indicators is not so obvious. But high impedance eliminates signal distortion and, indirectly, the volume level.

Specialists lead the impedance indicator to power, while voltage and current are taken into account simultaneously. The lower the impedance, the higher the sensitivity of the headphones. And vice versa - high resistance means low sensitivity. This indicator also affects electric current consumption. But this is in theory. The consumer must understand what sensitivity of the device is needed and how resistance affects it.

Here's what you need to remember:

Impedance does not affect volume, but sensitivity, as well as the maximum battery life of a smartphone, tablet or player. When connecting to a home theater or computer, there is no talk about battery life.
Sensitivity reflects the difference in volume levels as the input signal changes.
The higher the sensitivity, the louder the device sounds. This applies to microphones, speakers, and subwoofers.
Not every manufacturer provides a specific sensitivity value. But reputable companies indicate it either without units of measurement, or in the form of a ratio of frequency and power.
When a consumer changes the volume on an amplifier or sound source, he does not change the power, but he adjusts the output voltage level.
Impedance level also affects sound quality as it can remove distortion. This applies to car audio, smartphones, and other sources.
The resistance of the headphones affects the amplitude-frequency characteristics of the model. If it is increased, wave distortion is reduced and uniform characteristics can be achieved.

How does impedance affect sound quality?

In general, the effect of impedance follows the described rules. But there are also certain caveats that should be taken into account.

While impedance affects battery life, it is not the only factor that reduces battery life. The quality depends on the volume at which the user listens to music, and how much power is required to maintain operation in this mode. In addition, you need to consider the quality of the headphones themselves. The better the sound insulation, the less volume is required. Therefore, even with a high impedance, but when using closed-type models, the smartphone or player will work longer.

It can be concluded that:

Single-driver armature-type headphones have a higher average resistance than other types. With them, battery life will be longer.
Multi-driver headphones are produced with lower resistance. With them, the smartphone needs to be recharged more often.

Resistance affects the presence or absence of distortion. But the characteristics of the amplifier also play a role. If it can't supply the rated current, or the filter capacitance isn't up to par, distortion will still occur, no matter what the impedance or sensitivity of the headphones is.

Experienced acousticians say that slight distortion is inevitable. The human inner ear is designed in such a way that it itself becomes a source of distortion. For example, a person always hears the sound of stringed instruments with certain distortions.

The range of the auditory nerve is about 60 dB. So the user will not be able to hear most of the external distortions. Linear distortions resulting from changes in amplitude can interfere. And this is where impedance helps smooth them out.

Portable amplifier for optimal sound

High impedance headphones provide better sound quality but may be too quiet on portable devices. To prevent this problem from becoming acute, the power of the speakers must match the device. Otherwise, the sound volume will always be unsatisfactory. If you cannot achieve the desired sound by combining headphones with devices, try using a special amplifier.

Selecting headphones with the correct impedance helps the audio device function stably, last a long time and produce sound of fairly satisfactory quality. Good sound is appreciated not only by professionals who work every day in the music field. Any person would be pleased to have a device that produces clear, deep and beautiful sound. Annoying noises, too low a sound, or rapid battery drain can really ruin your mood.

The high impedance of the headphones ensures low current output. Due to this, less energy is consumed and less frequency distortion occurs. The amplitude and frequency characteristics of high-impedance headphones are equalized by working through an amplifier.

To understand what kind of resistance your device sounds like, determine what voltage your device is capable of. Small devices physically cannot create large voltages. A high output voltage is generated by stationary type devices that operate from the mains and not from a battery. Therefore, the impedance of headphones for stationary sound reproduction devices should be higher in order to fully enjoy the capabilities of good technology. However, a good amplifier can control the process of interaction of technical devices, smooth out shortcomings and reveal the potential of devices.

What is the impedance of different types of headphones?

These devices are divided into two types - full-size and in-ear (small headphones, in everyday life they are called “plugs” or earbuds). Within each group there is an additional division. Full-size headphones are divided into low-impedance (impedance up to 100 ohms) and high-impedance (impedance above 100 ohms).

In-channel gadgets are also divided into low- and high-impedance, only the numbers will be different - up to 32 Ohms (they produce standard versions with 16 and 24 Ohms) and more than 32 Ohms, respectively.

Manufacturers usually indicate the impedance value in average form. But for in-channel models it usually corresponds to reality. But for dynamic full-size gadgets, a big difference is possible, since the value depends on the position in space, and the same device may be characterized by resistance rises in the range of 32-64 Ohms. Much depends on the specific product, its design, housing features, etc.

But this does not mean that you should necessarily look for full-size dynamic headphones with a straight impedance line. Often, to achieve this indicator, the manufacturer reduces other characteristics. In top-class models, there may be devices with large deviations in impedance values. You need to take this into account when purchasing and select a model so that it matches the resistance of the amplifier.

Wireless headphones can also be full-size or in-ear. The required level of resistance corresponds to the given rules.

There are also hybrid headphones equipped with dynamic and armature drivers. They can also be low- and high-resistance, but they are characterized by significant jumps in resistance at medium and high frequencies, so choosing them is more difficult.

Amplitude-frequency response (AFC) of headphones

Frequency response – these three letters have probably been seen by everyone who has ever read reviews of musical equipment or descriptions of headphones and microphones. It is very rare to find the frequency response on a headphone box or in the accompanying documentation. So you can find the frequency response on special sites with reviews of specific headphone models. Why know the frequency response and what is it anyway? In a nutshell, frequency response is a graph showing the dependence of the loudness of a sound on its frequency.

It will become more clear if you look at the figure, where the horizontal axis shows the frequency of the sound signal (and frequency intervals with names), and the vertical axis shows the sound pressure level (loudness).

Based on the shape of the frequency response, you can predict what the tonal sound of the headphones will be like:

so-called “dark” (emphasis on low frequencies and lower mids, decline in high frequencies),
“light” (no decline in the high frequencies, rise in the upper middle),
“bright” (rise in the upper middle and high frequencies).

From the frequency response, you can also see the boundaries of the frequency range - those frequencies at which the final declines in the frequency response occur on both sides. The shape of the frequency response curve depends on the measurement technique and the measuring stand.

Selecting headphones by frequency response

1. We select for ourselves several models that we like according to any criterion.

2. We determine what tonal color we want to achieve and what frequency range to enhance, based on their musical preferences (bass, vocals, etc.).

3. We find the frequency response of the selected models on the Internet and study it. To enhance bass, there must be a rise in the midbass and a late fall in the lower bass. For emphasis on vocals - the middle without peaks and sharp declines. If you need headphones for vocals, then the middle should be without large peaks and valleys. For pronounced high frequencies there is a late decline in the highs and a relatively flat area at the tops.

If the type of frequency response in a certain range does not suit you, keep in mind the following:

Very narrow peaks and valleys may just be a defect in the measuring stand and may not reflect the real picture.
The frequency response at high frequencies can be wavy, the main thing is that there are no wide holes or hills.

How to measure headphone impedance?

Sometimes the procedure for measuring the indicator is mistakenly called impedancemetry. But it's actually the name of a diagnostic medical procedure. And for headphones, a standard resistance measurement is carried out. To obtain detailed relationships and graphs, a laboratory bench and special software will be required.

Impedance is measured in Ohms. But this does not mean that it can be determined using an ohmmeter. This is only an assumption, as if a resistor is connected to the electrical circuit instead of a real load. If the headphones are connected to a computer, then the measurement is performed by its sound card using special software.

The consumer should be aware of active resistance. You can find out how much this indicator is using a multimeter - this is a budget device that can be easily bought in an online store or borrowed from an electrician.

Headphone frequency range

The human ear perceives sound in the frequency range of 20 - 20,000 Hz, but this is ideal. With age, the upper limit decreases for everyone, and for those people who are often exposed to noise (work, loud music, etc.), the range of audibility quickly and significantly narrows, again due to high frequencies.

By finding a hearing test on the Internet, you can easily determine your hearing limits. Just for fun, because this information is unlikely to be useful to you when choosing headphones, except to warn you against listening to music too loudly in the future. You can read more about hearing hygiene here.

Most often, the description indicates the same standard range of 20 - 20,000 Hz, and this is just a reply from the manufacturer. But if volume deviations in the range are indicated, this is already a characteristic of the headphones. For example, if the description states 20 – 20000 Hz ± 6 dB, then this means that the frequency response curve of the headphones fluctuates in the range of 6 dB (along the vertical axis) in the specified frequency range. And this, in turn, means that there are no sharp peaks and dips in this range.

Thus, having seen the declared range of 10 - 25000 Hz, you must understand that almost always this is nothing more than a marketing ploy; you will not hear frequencies that go beyond the audibility range. But there are exceptions: a lowered lower limit of the frequency range leaves hope for the presence of sub-bass in the headphones (if the manufacturer was not lying), and an overestimated upper limit is justified for wireless headphones when there are distortions and codec noises in this HF region.

What is the best headphone impedance?

This parameter is selected depending on which device the headphones will be connected to. For example, if it is a smartphone or laptop, then people with experience recommend buying models with an impedance value of no more than 50 Ohms. No longer necessary, since compact devices like a phone or tablet cannot provide high volume levels and adequate power.

If a consumer chooses a gadget for a smartphone, then they will have to assume that a resistance of 22 ohms will produce louder sound. The model with an impedance of 32 Ohms gives a quiet sound. But the music will play 25% longer (approximately) compared to the first example.

To connect to a computer, you need models with a value of at least 50-60 Ohms. Such high-impedance headphones can even be connected to a music center. Experienced people recommend checking the sound quality and volume before purchasing such models. To do this, the headphones are connected to the device with which they plan to be used in the future. Models that provide clear sound are not necessarily expensive; they can be products with average performance, but reliable assembly,

If specific instructions are given by the manufacturer of the speaker or smartphone, it is better to follow them. Headphones with a high impedance mean increased energy consumption, but are better protected from short circuits or overheating.

The volume level of the device is affected by sensitivity. The indicator depends on the impedance of the headphones. Therefore, when choosing a model, you need to check or measure this energy consumption indicator yourself.

Optimal impedance values for use with various devices

High resistance sets low sensitivity in headphones. If you use headphones with different impedances on the same playback device, the battery power will be consumed at different rates. This happens because devices with different resistance values consume different amounts of electricity. To better understand what resistance is suitable for certain types of equipment, let's look at a few examples.

Some types of portable sound-reproducing devices:

Smartphone. To make the sound from your smartphone sound better, you should choose headphones with a nominal impedance of 22 ohms. However, in this case, the device's charge will be spent on playing sound files. On mobile devices, it is inconvenient to have a fast current drain. To keep the charge running longer, take 32 Ohm headphones. The listed standard values of 22 and 32 ohms work well in iPhone headphones. Monitor headphones for professional sound recording should be used with a smartphone only if a good portable sound amplifier is also connected to them. In addition, you also need a player with a powerful audio card. Low-impedance equipment is suitable for a smartphone.
A regular player is well compatible with devices with a resistance of 16 ohms. If the device's output voltage is more than 200 mV, use headphones with a lower sensitivity. A headphone impedance of 32 ohms is also suitable. Such devices consume less electricity, which means the operating time of the device is extended.

The average resistance in headphones with an armature device and a single driver is higher. This allows the gadget that reproduces sound to work longer. The charge of smartphones and players lasts for a longer period. This is important because modern devices already have enough programs that consume a lot of electricity even in the background.

Multi-driver reinforcement-type devices, on the contrary, have a lower average resistance. The same applies to the type of dynamic devices. This allows the equipment to work for a long time without the need for additional charge.

How does impedance work?

The choice of headphones should be approached taking into account their impedance. An important nuance is the type of technology. In the aggregate with which you will use them. Let's look at which technical gadgets (phones) this or that type of headphone is suitable for:

For portable equipment, it is recommended to choose headphones with a lower impedance,
For those who purchase headphones for stationary objects, a higher impedance of the headphones is needed.

Is there a golden mean? Certainly. The best impedance would be:

intended for portable devices, has a resistance of sixteen to twenty ohms.
For the latest European sound-reproducing devices, the impedance is excellent and will be exactly sixteen ohms.

Interesting facts: Previously, in the seventies, preference was given to a high level of impedance, because the output power of equipment of that period was often overestimated. Then resistors began to be used, which reduced the output voltage.

Sensitivity

Everyone has encountered a situation where some headphones sound louder than others, even though the level on the player (or smartphone) is set the same. This fact is often associated with the difference in headphone power. But headphones are not an amplifier; this premise is fundamentally wrong.

In fact, how loud the headphones will sound depends on their sensitivity. Traditionally, this parameter lies in the range of 90–120 dB, and for most models available on the market this range is already 95–105 dB. Sensitivity shows how loud the headphones will play, all other things being equal. The higher it is, the higher the maximum volume and the less load on the built-in amplifier of the player or smartphone. I noticed another direct relationship: the cheaper the headphones, the less likely it is that their real (and not indicated in the technical data sheet) sensitivity will be high.

Headphones AKG K 315. Sensitivity - 126 dB, impedance - 32 Ohms, maximum input power - 15 mW.

Rating of low-impedance headphones: TOP-8 best models

If you have already decided what headphone impedance will be most suitable for your smartphone or audio player model, all that remains is to choose from a huge assortment the highest quality product at the best price. To make this truly difficult task easier, we have compiled a rating of the best headphones with acoustic impedance of 16 and 32 Ohms and analyzed in detail all the advantages and disadvantages of each model. This will help you finally make sure that your choice is correct, as well as avoid unnecessary expenses on overpriced equipment.

16 Ohm Headphones

In this section, we will introduce you to the best headphone models with an acoustic impedance of 16 ohms. These are inexpensive headphones with average sound quality and clarity, which are suitable for short-term use, for example, during a morning or evening run.

Koss KEB32

Koss KEB32 is one of the most budget models made in China, which belongs to the FitBuds series. This is a sports series, so all models are made in several bright rich colors (green, red, blue, purple and yellow-green). The peculiarity and at the same time “trick” of these headphones is the fact that Dara Torres, a four-time winner of silver and bronze medals at the Olympic Games in the category “Sport Swimming,” took part in the development of the appearance and design.

The headphones have a well-thought-out design, a wear-resistant cable and are lightweight. Their body is made of washable plastic, from which traces of dirt, dust and sweat are easily removed. The acoustic resistance of this model is 16 Ohms, but despite this, they create a fairly high-quality and clear sound. The disadvantages regarding the sound include a small low frequency range, but this is not particularly critical considering the more than affordable price.

Main characteristics:

name/manufacturer – Koss KEB32;
headphone type – in-ear headphones;
connection – wired;
acoustic system – closed with two sound channels;
acoustic impedance – 16 Ohms;
maximum volume – 100 dB;
features – sports series;
the average cost is 400 rubles.

pros

one of the most budget models in its category;
stylish appearance, bright, rich colors;
the body is made of washable material (plastic);
The set includes three pairs of interchangeable silicone ear pads of different sizes;
good clean sound.

Minuses

few low frequencies;
inconvenient shape of the ear pads (the headphones constantly fall out of the ear);
very small print of the “right/left” marking (people with poor vision may encounter difficulties in determining this parameter, since both headphones are almost symmetrical in appearance).

Koss KEB32 are good and inexpensive headphones with a 3.5 mm plug and an acoustic impedance of 16 Ohms. Of course, the model has its drawbacks, but given the low cost, you can turn a blind eye to them, especially since the sound quality of this model is quite decent. When choosing this model, keep in mind that the ear pads in it are made of silicone of increased rigidity, which you need to get used to.

Kitsound Mini

Kitsound Mini are good wired headphones with standard characteristics for the budget category, made in China. They are very light (weight is only 33 g, which is 2-2.5 times less than any other headphones), have a plastic body and a 3.5 mm plug, which allows you to connect them to any smartphone, tablet, player or e-book. An important feature that determines the higher price compared to analogues is the presence of a built-in microphone, so these headphones can also be used as a headset for conversations when your hands are full. For the same purpose, the model is equipped with a one-button remote control, which, when connected to a smartphone, allows you to quickly receive a call, and after finishing the conversation, switch to listening mode with one touch.

Main characteristics:

name/manufacturer – Kitsound Mini;
headphone type – in-ear headphones;
connection – wired;
acoustic system – closed;
acoustic impedance – 16 Ohms;
maximum volume – 100 dB;
features – Mini series;
the average cost is 800 rubles.

pros

belongs to the middle price category (affordable for most buyers);
very light model - the headphones weigh only 33 g;
The set includes three pairs of interchangeable ear pads of different sizes and shapes;
the model is equipped with a built-in microphone and remote control (can be used as a headset);
strong and flexible cable;
normal sound quality.

Minuses

very small ear pads (explained by the concept of this model);
weak noise reduction system;
very low quality plastic elements.

Considering that the Kitsound Mini headphones can also be used as a headset, they could easily compete for a higher position in our rating, but due to their low quality and fragility, we give them only the penultimate place. Overall, this model is good for listening to music while jogging, cleaning, and doing other things, but it's definitely not worth the money.

Philips SHE3555

Another low-impedance headphone that is manufactured in China is the Philips SHE3555. Philips is known throughout the world as one of the most reliable manufacturers of household appliances and electronics, so the products of this brand are traditionally of high quality and meet all the standards required for this category of goods. Philips SHE3555 headphones are equipped with a universal sound tube in the shape of an elongated oval, and specially ergonomically shaped ear pads provide a comfortable fit and prevent the equipment from falling out of the ear. This model belongs to the Upbeat series and has powerful drivers, thanks to which very clear and high-quality stereo sound is achieved. These headphones also differ from previous samples in the ability to adjust volume and control playback.

Main characteristics:

name/manufacturer – Philips SHE3555;
headphone type – in-ear headphones;
connection – wired;
acoustic system – closed with two sound channels;
acoustic impedance – 16 Ohms;
maximum volume – 101 dB;
features - powerful emitters;
The average cost is 600 rubles.

pros

affordable price;
good bass thanks to the built-in Upbeat system;
there is the ability to adjust the volume and playback control function;
strong cable bend for longer service life;
The set includes three pairs of silicone earbuds of different sizes;
the model is very light (the weight of the device is about 15 g);
Can be used as a headset for your phone (there is a built-in microphone).

Minuses

The wire is a little short (although the instructions state that its length is 1.2 m - a standard indicator for this type of headphones).

Philips SHE3555 are classic headphones, made in a traditional style in four standard colors: black, white, blue and red. Like most products under the Philips brand, they are of fairly high quality, and as for the sound, there is absolutely nothing to complain about here (do not forget that in this section we are considering models with an acoustic impedance of 16 Ohms).

32 ohm headphones

Headphones with an acoustic impedance of 32 Ohms are more expensive than 16 Ohm models, but their sound quality is much higher. Most of these headphones are wireless models that connect to a mobile or portable device using Bluetooth.

JBL Tune 205BT

The JBL Tune 205BT Wireless Headphones feature built-in Pure Bass technology that ensures the sound from your speakers is always clear, big, stable and powerful (no matter what type of music you prefer). The design of the headphones is very well thought out: the body is light weight, and the earbuds have an ergonomic anatomical shape that ensures a comfortable fit. These features make the headphones comfortable to wear even if you listen to music for hours on end. A full charging cycle for this model is enough for 5-6 hours of active use, and the durable cable does not fray or get tangled.

Main characteristics:

name/manufacturer – JBL Tune 205BT;
headphone type – Bluetooth headphones;
connection – wireless;
acoustic system – closed;
acoustic impedance – 32 Ohm;
maximum volume – 100 dB;
features – fast charging;
signal range – 10 m;
The average cost is 2000 rubles.

pros

clear, rich and spacious sound thanks to the proprietary Pure Bass sound system;
A full charging cycle is enough for 5-6 hours of listening;
The model is equipped with a flat cable that does not fray or get tangled;
there is a built-in microphone and a button for adjusting and switching between modes;
indoor signal range is up to 10 m;
several colors (in addition to the classic black color, the model is also available in blue, silver, gold, and rose gold);
The device is fully charged in 2 hours.

Minuses

quiet microphone (the interlocutor may not hear you well);
They do not fit very tightly and may periodically fall out of the ear.

JBL Tune 205BT headphones are among the top five best-selling wireless models, as they are distinguished not only by a very affordable price, but also by good sound quality. Minor disadvantages, in general, do not affect the main functions of the device, but if you are looking for not only good headphones, but also a high-quality headset, it is better to take a closer look at other models - the quality of the microphone here is frankly poor.

Xiaomi Mi Basic

Xiaomi Mi Basic is one of the most popular low-impedance headphones with wireless data transmission via a high-speed Bluetooth connection. They are great for listening to audio content while walking, jogging or sports training, as they are equipped with an optimal degree of sound insulation, which is provided by a closed-type speaker system. The model is equipped with a built-in microphone and voice control, as well as a powerful battery, the charge of which lasts for almost a week of active use. A special charging case, two pairs of replaceable earbuds made of high-density soft silicone, power-on and charge level indicators are all pleasant bonuses that make using the device not only simple, but also as comfortable as possible.

Main characteristics:

name/manufacturer – Xiaomi Mi Basic;
headphone type – Bluetooth headphones;
connection – wireless;
acoustic system – closed;
acoustic impedance – 32 Ohm;
maximum volume – 100 dB;
features – high-capacity battery;
signal range – 10 m;
the average cost is 2600 rubles.

pros

excellent sound quality and high build quality;
fit comfortably in the ear;
high-speed connection to smartphones and other portable devices;
can be used as a headset;
there is a voice control function;
The kit includes a charging case, and a full charging cycle is enough for almost a week of regular use (in continuous mode - up to 4 hours).

Minuses

no charging cable.

Of course, the price of Xiaomi Mi Basic headphones is quite high, but if you consider that this is a wireless model, then it can be called almost “penny,” especially since the Xiaomi brand has long established itself as one of the best manufacturers of electronic and digital gadgets.

Philips SHB4205WT/00

Philips SHB4205WT/00 wireless headphones, which are also a high-quality stereo headset, are an excellent choice for lovers of an active life and anyone who often listens to music or other audio files from a smartphone or other mobile devices. These headphones pick up a signal using a high-speed connection at a range of up to 10 meters, do not fall out of the ear even while running and other sports, and on top of that they have a stylish design. Additional advantages include a comfortable, ergonomically shaped neck strap that does not chafe the skin even after prolonged use, as well as high-quality surround sound and an effective passive noise reduction system. The manufacturer considers the presence of fashionable glossy inserts on the plastic case and the presence of convenient controls to be a successful solution.

Main characteristics:

name/manufacturer – Philips SHB4205WT/00;
headphone type – Bluetooth headphones;
connection – wireless;
acoustic system – closed;
acoustic impedance – 32 Ohm;
maximum volume – 105 dB;
features – glossy metal inserts on the body;
signal range – 10 m;
the average cost is 2600 rubles.

pros

clear, high-quality, surround sound;
the headphones fit tightly in the ear and do not fall out during shaking, so they are great for sports and morning/evening runs;
convenient control and adjustment system;
can be used as a headset;
compact size and low weight;
stylish appearance (shiny metal inserts successfully emphasize the whole image);
when there is an incoming call, a soft vibration signal is heard;
comfortable neck mount that does not rub the skin even when worn for a long time;
hold charge well.

Minuses

the only drawback noted by the owners of this model is the slightly thin wires, but this does not affect the quality in any way.

Philips SHB 4205 WT/00 headphones are one of the most successful options among low-impedance models. Despite the fact that many young and ambitious manufacturers have now appeared on the market, the Philips brand consistently “keeps its mark” and produces high-quality products that traditionally occupy leading positions in all ratings.

Children's headphones

Children's headphones differ from adult models not only in appearance and characteristic children's design, but also in technical characteristics, among which the most important are the maximum volume level, acoustic impedance (resistance) and noise reduction system. Almost all children's models have a resistance of 32 Ohms, since in childhood, when the auditory system is most vulnerable, sound quality and purity are especially important.

Harper Kids HK-39

Harper Kids HK-39 headphones were developed by South Korean specialists specifically for children, taking into account age characteristics and safety requirements for this category of users. All earbuds for these headphones have an anatomical shape and different sizes, adapted to each age group. These headphones are capable of reproducing sound over a wide range of frequencies with an acoustic impedance of 32 ohms, so the reproduced sound is clear and balanced, without any distortion or interference.

Like the “adult” models in the mid-segment, this model is equipped with a multifunctional control button, with which you can switch between listening and talking modes (the headphones are equipped with a built-in microphone), as well as manage playback files.

Main characteristics:

name/manufacturer – Harper Kids HK-39;
headphone type – in-ear headphones;
connection – wired;
acoustic system – closed with two sound channels;
acoustic impedance – 32 Ohm;
maximum volume – 96 dB;
features – children's model;
The average cost is 600 rubles.

pros

high sound quality due to the ability to reproduce a wide range of frequencies;
rich colors;
The set includes a special zippered storage case with images of funny cartoon characters;
comfortable and soft anatomically shaped inserts, adapted for each age group;
compact size and light weight;
reliable body of high quality assembly;
affordable price (analogues are 2-3 times more expensive).

Minuses

The only drawback of this model can be considered a fairly high percentage of manufacturing defects (about 5%), but a low-quality product can be exchanged without problems or the money spent on it returned.

Harper Kids HK-39 are very bright, stylish and comfortable headphones for children and teenagers over 8-10 years old. The “trick” of this model is the original zippered case, made in the same color scheme as the product body, which prevents wires from getting tangled and makes them easier to store. High-quality sound, fashionable design, affordable price - this model definitely deserves to be among the leaders.

What else to consider when choosing: sensitivity

Typically, the higher the impedance of the headphones, the lower their sensitivity. Consequently, a higher voltage is required to drive the headphones to operating volume. A low-power amplifier will not cope here, which means that it will not be possible to achieve sufficient volume from such a combination. For smartphones, it is better to take headphones with high sensitivity (from 100 dB/mW) . If it is below 95 dB/mW, the headphones will most likely need a powerful amplifier.

However, low impedance does not always mean that headphones are easy to drive. For example, some models with planar magnetic emitters can be low-resistance, but at the same time extremely tight. Thus, MyST Ortophones with a resistance of 18 Ohms have a sensitivity of only 77 dB/mW.

There are also exceptions where high-impedance headphones are sensitive enough to be used with a smartphone. Perhaps the most “popular” example is Koss Porta Pro. With a fairly high resistance of 60 Ohms, their sensitivity is 101 dB/mW, which is enough for a modern smartphone. But even if the volume is sufficient, the sound still suffers from a lack of gain, which primarily affects the low frequencies - with a more powerful source their development will be better.

What else to consider when choosing: impedance and headphone design

In fact, the issue of headphone impedance is more complex than it seems at first glance. Often it is impossible to say for sure whether it is low or high. And that's why.

Headphones do not operate at one frequency, but reproduce the entire spectrum audible to humans. Therefore, they have a complex resistance, the value of which depends on the frequency - this characteristic is called impedance . This is what is indicated on boxes with headphones, taking the resistance for a frequency of 1 kHz.

Different headphones have different impedance characteristics. For example, in dynamic and planar magnetic models the impedance is linear. That is, if the box says that it is equal to 32 Ohms, then this is true for the entire frequency range. Consequently, the dependence on the source is reduced, since the voltage drop at all frequencies is approximately the same - the frequency response will not be distorted by different output resistance.

Impedance of dynamic Beyerdynamic DT 250 (250 Ohms). Slight increase in resistance at low frequencies up to 200 Hz. On the rest of the spectrum, the impedance is linear—the dependence on the source is minimal. Source: Reference Audio Analyzer

Impedance of planar magnetic HIFIMAN He-400 (35 Ohms). The value is maintained across the entire frequency spectrum, so source dependence is minimal. Source: Reference Audio Analyzer

In armature headphones, the impedance is nonlinear. Single-driver models have a rise in resistance at high frequencies, which improves their control and does not cause difficulties in selecting a source. The impedance of multi-driver headphones has many ups and downs, and its unevenness over the entire range can reach 100 Ohms. So it turns out that at one frequency they are low-resistance, and at another they are already high-resistance.

Impedance reinforcement Etymotic ER-4 (32 Ohms at 1 kHz, 60 Ohms at frequencies above 10 kHz). High HF impedance improves their control, which has a positive effect on sound quality. Source: Reference Audio Analyzer

Impedance of multi-driver FitEar 335 DW (57 Ohms at 1 kHz, 112 Ohms at 3 kHz). At a frequency of 10 kHz, the impedance value is only 17 Ohms - you need a high-quality source to avoid distortion at HF. Source: Reference Audio Analyzer

It is multi-driver models that behave unpredictably with different sources, especially if they have high output resistance - the difference in voltage drop at different frequencies increases the unevenness of the frequency response. In addition, such headphones can emphasize nonlinear distortions of the source, so they need a high-quality Hi-Fi player .

The influence of different output impedance on the frequency response of FitEar 335 DW. The higher the output impedance of the source, the more the frequency response is distorted. Source: Reference Audio Analyzer