After the interview, the largest number of questions related to the resistance characteristics of the headphones. Let's consider what the characteristic affects and what it is eaten with. To better assimilate the material, we will consistently release materials, collect questions and comments, and move on.
Before we figure out what and how the resistance of the headphones affects, let’s figure out what kind of overseas bird this is. And we are preparing for the fact that there will be as many as two formulas from a standard school physics course. Those. the material is complex and heavy.
Resistance headphones are often called impedance or headphone impedance.
From the point of view of terms, where resistance means only the active (resistive) part, impedance (impedance) means the combination of active and reactive resistance. Remembering the school physics course, we know that reactance includes capacitance and inductance.
The final impedance of the headphones depends on the frequency at which the impedance is measured. On boxes, only the active resistance or occasionally the value obtained at a frequency of 1 kHz is often given. Unfortunately, the accompanying parameters are rarely indicated and one can only guess what the actual impedance value of the headphones is.
If we are talking about dynamic headphones, then the values are in the form of 16, 24, 32 Ohms, etc. mean only the resistance of the speaker inductor and do not take into account the resistance of the wire, soldered contacts and plug. In reality, headphone impedance is usually 1-3 ohms higher and varies slightly between the right and left channels. The most conscientious manufacturers honestly indicate that the accuracy of the indicated resistance is 20 or 30% and this is normal (only the marketer vigorously objects to this; no errors can be shown on the box - “truth” kills sales).
Low and high impedance headphones
Headphones are usually divided into low-impedance and high-impedance. For in-ear and full-size headphones, the separation boundary is different.
For full-size ones: low-impedance headphones have an impedance of less than 100 ohms, and high-impedance ones have a resistance above 100 ohms.
For in-channel ones: low-impedance not higher than 32 Ohms, higher than 32 Ohms – high-impedance.
What type of impedance do different headphones have?
In-ear headphones
Majority in-ear dynamic headphones have a flat impedance curve and values of 16, 24 or 32 ohms have no deviations for frequencies from 20 to 20 kHz.
The graph shows frequencies horizontally, from 20 Hz to 20 kHz. Vertical – resistance (on a logarithmic scale).
Over-ear dynamic headphones
U full-size dynamic headphones quite often you can find an uneven impedance curve, with local rises in the area low frequencies and a slight increase in the high frequencies.
The resistance can be equal to 32 Ohms without taking into account the reactive part (conventionally, this is 0 Hz, measured by any universal multimeter), but in practice it can be twice as high at certain frequencies.
Unevenness (rises) can indicate both resonances and design features of the emitter in a given headphone housing. So, when measuring resistance, the frequency and magnitude of the rise can vary greatly depending on whether the headphones are lying freely on the table or are put on a mannequin (in this case, the internal space of the headphones is damped).
Some dynamic headphones have no noticeable resonances or deviations. This line is conventionally ideal, but selecting headphones this way is not recommended. In pursuit of improving one characteristic, you have to sacrifice another.
Among top-class headphones you can find impedance curves with both minimal deviations and significant ones. If the headphones show a narrow-band boost (in the graph above this is the Grado GS1000), then the amplifier should be selected with a low output impedance for better control low frequencies (as, by the way, it was done with the proprietary Grado RA1 amplifier).
Isodynamic (orthodynamic) headphones
In addition to dynamic emitters, isodynamic emitter type(and its similar type - orthodynamic). These headphones always have a straight impedance line. Isodynamic headphones are now produced by: Abyss, Audez"e, HiFiMan, Oppo, Fostex. In Soviet times there were TDS-5/m, TDS-7, TDS-15, TDS-16 and TDS-25 headphones. Today for TDS-7 models and TDS-15 are most often modded.
Formally, this is an ideal load for an amplifier, however, in the ultra-high frequency range (megahertz and gigahertz), the resistance of some models decreases and approaches zero. Such insidiousness cannot be seen on a standard chart, and with some amplifiers this can lead to poor-quality operation.
In-ear reinforcement headphones
The impedance looks hardly predictable in-ear headphones with reinforcement radiator. For single-driver models there is common feature- there is always a local rise in the upper midrange (around 1-3 kHz) and in the highest frequencies. Thanks to the high-frequency boost, most single-driver armature models “sound clean” in the high-frequency region, because in this frequency range the amplifier produces less distortion.
In the low-frequency region, the typical resistance is 8, 16, 24 or 32 ohms. Above 500 Hz rises begin.
If a resistance of 100 Ohms at 1 kHz is indicated, this does not mean that the headphones are high-impedance; their resistance may be only 16 Ohms according to the readings of the multimeter (in the low frequency region).
Hybrid and multi-driver headphones
It is impossible to predict the impedance curve for multi-driver And hybrid in-ear headphones. The impedance curve can be anything above 500 Hz. The resistance drop can easily reach 4 ohms with the stated 100 ohms at 1 kHz.
General conclusions
- Resistance in reality it will be like on the box, if headphones: In-channel dynamic or isodynamic
- Resistance in reality will be like on a box and have unknown lifts, if headphones: Dynamic invoices and p full-size
- Resistance in reality It will NOT be like on the box, if headphones: reinforcing or hybrid
Why actually know all this? Sometimes manufacturers of amplifiers and players indicate what headphone impedance will be compatible and it is useful to rely on this information.
If you need to find out the real resistance of armature or hybrid headphones, you can try searching for measurement results on the Internet. Methods for measuring impedance usually give a single result and do not depend on the software with the stand or the measuring complex.
What does headphone impedance affect?
Headphone sensitivity
The sensitivity of headphones is usually reduced to power, which takes into account two characteristics at once: the voltage and current supplied to the headphones. This is a convenient final characteristic for theorists and extremely confusing for practical application end consumers.
For the average consumer, it is logical to think of “sensitivity = volume.” This works with speakers, because... the value is always indicated by the speaker resistance in the form of 4 or 8 ohms, and the power of the amplifier is indicated similarly. It's hard to get confused.
But if for speakers there are only two standard resistances of 4 and 8 Ohms and each amplifier has power for two types of resistance, then headphones have about 11 resistances: 8,16,24,32,64,128,256,320, 608, etc.
As a result, the consumer picks up headphones with different impedances and naively believes that he can compare something in terms of sensitivity.
For the sensitivity = loudness relationship to apply to headphones, sensitivity must be expressed in terms of voltage rather than power (as Sennheiser does). But most manufacturers don't indicate at all, in what units the sensitivity is given.
This is why “everyone knows” - that high-impedance headphones are quiet, and low-impedance headphones are loud. And they naively believe that high-impedance headphones require a “powerful amplifier,” while low-impedance headphones require a crummy smartphone. And although in reality everything is completely different, due to extremely unfortunate terms from the GOST and AES standards, separate “concepts” were formed that contradict the laws of physics, but in common language quite accurately describe the result, like: “High-impedance headphones need a powerful amplifier.” Physically illiterate, but “everything is clear to everyone.”
Let's touch on this topic deeper (be careful, we're moving on to formulas from school, we're starting to strain our brains!)
At the output of the amplifier, we do not directly regulate the power at all, but only the voltage level. Depending on the resistance of the headphones, the level of current consumed by the headphones is determined, which in turn determines the resulting power level.
This is very important to understand, because... Without changing the voltage level at the output of the amplifier, we physically cannot separately increase the current level and thereby increase the power level.
U=I*R, Where
I – current strength, A
R – headphone resistance, Ohm
W=I*U, Where
W – amplifier output power, W
U – amplifier output voltage, V
I – current strength, A
They also write resistance. This article explains what it is, why it is needed, and what impedance affects.
Note: Since impedance is total resistance, which includes both its active and reactive components, you need to know that most often the first - active - value is indicated on packages. Because of this, a deviation from the declared parameters of 1-3 Ohms is considered normal.
Which option should you prefer? Which resistance indicator should you choose? What should it be like? What matters here is the type of equipment to which the headphones will be connected, and the power of its amplifier.
Why do we need different resistance values for different models?
Headphones different types differ in the quality of sound production: high-impedance ones sound a little better. But the point here is not the resistance as such, but the fact that the amplifier sends less current, and therefore distorts the frequency signal less.
For portable devices - MP3 players and tablets - it is better to select headphones that belong to the low-impedance type. If the headphones will be used at home, for example, connected to a PC or sound card, high-resistance models are suitable.
The fact is that devices portable type The voltage level at the output is limited, but there are no restrictions on the current. Because of this, you can “boost” the gadget in order to squeeze maximum power out of it only with low-impedance headphones.
The voltage of devices that belong to the stationary type is not so limited, so you can get excellent power using high-impedance models. This option will give the amplifier a more favorable load. With high impedance headphones, there will be less distortion in this case.
Note: for a smartphone or is it better to choose an option up to 50 Ohms. A model with a larger indicator will be suitable if it has a good sensitivity margin.
Resistance itself does not affect the sound (its volume and quality), but is responsible for these parameters in conjunction with SPL. This indicator determines how loud the headphones can sound. But how much power an amplifier can produce is the prerogative of impedance.
If you take two pairs of headphones that have the same SPL values, say 110 decibels per megawatt, but one model is 16-ohm and the other is 150-ohm, and connect them to a single-voltage player, then in each of the two cases the player will sound different. different:
- with a low-impedance model - 62 mW;
- with high resistance - 7 mW.
Simply put, his amplifier will not be able to get the most out of a high-impedance model.
Devices from the high-resistance category are used in the Hi-End. They are connected to amplifiers or 24-bit studio sound cards. This gives a higher quality and balanced audio signal. For this reason, high-impedance models are used by film and TV sound engineers and DJs. They are also used in mastering and mixing sound recordings in project studios.
Advice: a good studio option - . In addition to decent impedance, they will delight you with excellent sensitivity and a wide frequency range. They sound balanced and detailed.
Headphone volume and source power consumption
Since the volume depends on the resistance, this value also affects the energy consumption of the carrier’s battery: if you listen to music at maximum, then high-impedance and low-impedance models will spend the energy of the battery or smartphone differently.
The higher the resistance, the longer the device’s battery will “live” on one charge, be it a smartphone, player or other gadget. This is because high-impedance headphones consume less current, and this does not depend on the final actual volume.
Users of “quiet” smartphones have an extremely limited choice of headphones, since there is only one option - low-impedance “ears”. Users with gadgets that are equipped with a fairly powerful output (at least 3 V) have the opportunity to experiment.
There are two best options here:
- low resistance but high SPL;
- less sensitive, but with higher impedance.
So, if a user changes 16-ohm headphones to 32-ohm ones (for example, sports ones), the battery of his gadget will last longer.
Headphone models can sound good regardless of the number of ohms. But a lot depends on the medium. For a smartphone, it is better to choose a low-impedance option. To make the battery last longer, a model from 32 Ohm is suitable. For mixing audio recordings, as well as mastering audio tracks and other studio work, it is worth taking a closer look at full-size options with high impedance. If you connect a low-impedance model to studio equipment, the volume will, of course, increase, but the frequency balance may be disrupted.
The value of the data indicated by the manufacturer on the packaging with headphones, as a rule, does not tell the average consumer anything, so many sales consultants, taking advantage of the buyer’s ignorance, easily “hang noodles” and sell off the stale goods. To prevent this from happening to you, you should learn to understand the basic technical parameters of headphones and their meaning on your own.
Frequency characteristics without indicating the harmonic distortion coefficient are worthless, and a flat frequency response graph does not guarantee high sound detail.
The frequency range in headphones and its meaning.
It is generally accepted that the higher the boundaries of the frequency range, the better quality sound. But as we know from a biology textbook, a person is able to distinguish sound in the range from 20 Hz to 20 kHz. Then why do manufacturers of various audio devices produce products with frequencies exceeding the audible range? hearing aid a person is two to three or more times higher.
If in the frequency characteristics of the headphone model you like you see values exceeding the limits of the audible region, this is more likely a plus than a minus. Such speakers are capable of operating not only in a narrow boundary mode, but also have additional potential for more accurate, distortion-free transmission of audible frequencies.
Speaker size and headphone power.
The diameter of a speaker is just its size and nothing more, but for some reason many buyers are consciously or subconsciously convinced of the relationship between the size of the driver (aka speaker) and the sound quality of the acoustics.
The speaker size characteristic is meaningless; in fact, it is a marketing ploy designed for the stereotype of an unenlightened buyer.
Acoustic power matters when choosing. This parameter tells us about the output power of the speakers and affects their volume. The higher the headphone power value, the richer, brighter the sound, the greater the bass, and the more accurate the interpretation.
High power headphones from 2000 mW and above will drain your battery much faster. portable device. If the power of the sound source exceeds the maximum permissible for the headphones, they may be damaged. Consider these nuances when choosing.
What affects the sensitivity of headphones?
Let me answer briefly - the sensitivity parameter is responsible for the sound volume. With the same headphone power, those whose sensitivity is higher will sound louder. Focus on a sensitivity rating of 90 dB and above; such devices can be considered good.
What does impedance mean in headphones?
What affects resistance or what is impedance in headphones? This technical parameter means the following: the greater the resistance (impedance)
headphones, the more powerful the incoming signal must be to swing the membrane.
Thus, for players and other portable gadgets, the acceptable headphone impedance is 16-50 Ohms. More powerful headphones with an impedance of 250 Ohms will require a sound source more powerful than a conventional player, of course they will work from a standard player, but powerful sound you won't get it.
There is the following pattern: the higher the resistance, the clearer and purer the sound. Therefore, low-impedance headphones can transmit sound with distortion, while high-impedance headphones are not loud enough when the power of the outgoing signal source is low.
A good choice for a portable player and computer would be headphones with an impedance of 32-80 Ohms. For more professional work in the studio, etc., the headphone impedance can be from 200 Ohms and higher using sound amplifiers.
When choosing headphones, for example for a player, take into account its power and the impedance of headphones it is designed for. Typically, portable gadgets are designed to work with low-impedance head-mounted monitors with a resistance of 32 ohms.
Frequency response - amplitude-frequency response of headphones.
Frequency response is one of the visual ways to present the sound of head monitors in the form of a graph. As a rule, this is a curve on which you can see how certain headphones transmit frequencies. The fewer sharp bends there are in the graph and the further it goes this line the more accurately the monitors transmit the original audio material. Bass lovers can use the frequency response graph to understand whether these headphones are suitable for them or not; there should be a “hump” in the low-frequency region of the graph. The higher the graph extends, the louder the sound of the headphones.
A flat frequency response line does not guarantee High Quality sound. This gives us reason to believe that the sound in the headphones is balanced, in other words, the low frequencies do not roll over or stick out, and do not hurt the hearing.
Nonlinear (harmonic) distortion factor.
In Western literature, they usually use THD - harmonic distortion coefficient, while in domestic literature they traditionally prefer THD - coefficient nonlinear distortion. This is perhaps the only parameter by which you can judge the sound quality. If you want to get high quality sound from your headphones, choose models with a harmonic distortion coefficient of less than 0.5%. Head-mounted monitors with an indicator of more than 1% can be considered mediocre.
Very often you will not find this indicator on the packaging or on the official website of some manufacturers; perhaps the manufacturer has something to hide, this is a reason to think about it. For example, the widely advertised Beats by Dr. headphones, popular among young people. Dre Studio has a THD of 1.5% at 1kHz.
If you found this characteristic In the description of the model you like, pay attention to what frequency this indicator is indicated for. The fact is that the harmonic distortion coefficient is not constant over the entire frequency spectrum. Due to the fact that the human ear hears the low frequency region less clearly, in low frequency range Harmonic distortion up to 10% is permissible, but in the frequency range from 100 Hz to 2 kHz - no more than 1%.
The best headphone manufacturers
Now you know the importance of the characteristics of headphones and you are unlikely to buy a “pig in a poke”, but I still advise you to choose head monitors from well-known brands, time-tested and proven to be good.
Here are some reliable companies: AKG, Beyerdynamics, Sennheiser, Audio-Technica, Grado, KOSS, Sony, Fostex, Denon, Bose, Shure. IN model range There are dozens of headphone models from these manufacturers, but whatever one may say, they are all made using similar technologies, so their accents are very similar.
Fans of classic rock should take a closer look at the KOSS models; they have a pronounced bass. Head monitors under the AKG brand are famous for their “beauty” - the detail of high frequencies. Headphones from the German company Sennheizer usually have a relatively flat frequency response, which indicates good balance without falling or bulging frequencies.
What do the letters in the name of the headphones mean?
The letter prefix in the name of the head monitors indicates the design features and some technical details of the model.
Here is an example of smart labeling of Sennheiser headphones:
- CX, as well as the IE series - in-ear headphones;
- MX - in-ear headphones;
- HD - classic with headband;
- RS - wireless, base and headphones included;
- HDR - additional pair of wireless headphones;
- OMX - plug-in with hook type fastening;
- OCX - in-channel with hook type fastening;
- PMX - overhead or plug-in with an occipital arch;
- PXC - a line of headphones with an active noise reduction system;
- PC - computer headsets;
- HME - headset models designed for pilots and crews of airplanes and helicopters.
If you see the index “i” at the end of the model name, then you are looking at headphones that can work with Apple gadgets.
The final values of the main technical characteristics of head-mounted monitors should be as follows.
1. The size of the speakers does not matter from a technical point of view.
2. Acoustic power - The higher the power value, the “brighter” the sound, the higher the bass, the more accurate the interpretation.
3. Sensitivity - from 90 dB and above can be called good.
4. Resistance (impedance) - for a portable player and computer, choose head monitors with an impedance of 32-80 Ohms. For studio work from 200 Ohms and above.
5. Harmonic distortion coefficient - high quality sound will be provided by models with a harmonic distortion coefficient of less than 0.5%. Head-mounted monitors with an indicator of more than 1% can be considered mediocre.
Have a nice day and good luck in choosing headphones!
Resistance electrical circuit- this is its ability to resist passing current. The units of measurement for this parameter are called ohms. We remembered this definition back in school, studying a physics textbook. That is, the greater the resistance value, the less electric current can pass through this device, and vice versa. This also applies to, only their resistance is called loudly and beautifully - impedance. It is this that largely determines such qualities as the level of interference and sound volume.
To hear rich and clear sound in your headphones, select their resistance value as close as possible to the parameters of the amplifier. Otherwise, even the most expensive headphone model will not be able to show itself in all its glory, and you will be very disappointed. In addition, a mismatch between input and output impedance can even lead to equipment damage. For example, if you take headphones with a low impedance and connect them to a high-impedance output device, you will end up with a lot of distortion, and often just an unpleasant grinding sound.
If you do everything exactly the opposite, you will have to constantly turn up the volume of the sound, but it will still be too quiet. The very high impedance of headphones, of course, fights interference well, but at the same time it also noticeably reduces the signal level. Therefore, such equipment is only suitable for professional recording studios, where there are sufficiently powerful amplifiers. In this case, the high impedance also protects the delicate thin membranes of the headphones - after all, they can simply tear from a very loud sound. When you turn off the music, you will hear only silence without any interference - this is a big plus of high resistance.
But in order to listen to a player or radio, high-impedance headphones are not required at all - as mentioned above, they will make the sound too quiet. The most acceptable impedance value for everyday use is 32 ohms. There are also 16 ohm models. They make it possible to listen to music louder, so these “ears” can be recommended to lovers of incendiary compositions. If you need headphones for listening to audiobooks, for example, then a resistance of 32 ohms or a little more will be quite suitable.
So, when choosing headphones, carefully read their characteristics. An impedance of 250 ohms and higher is needed only for powerful studio equipment. If you are looking for headphones for a computer or player, choose models with an impedance of 32 to 80 ohms. Those who like very loud sound should pay attention to the impedance value of 16 ohms.
Prepared by the online store "130 dB"
Headphone impedance is its input resistance. Many of their technical and operational characteristics depend on it.
If your headphones have low impedance (25 ohms or less), they require less power to produce high quality sound. These headphones are well suited for use with devices such as music players, Cell phones and other portable devices.
And if the headphone impedance is more than 25 ohms, then they require more energy for high sound levels. This resistance protects them from possible damage caused by overloads. These headphones can be used with a wide range of audio devices. For example, these include models used for DJing, the nominal resistance of which is about 25-70 Ohms.
If the impedance of headphones is low, they become more susceptible to damage when using more powerful amplifiers. If you, for example, connect low-impedance headphones to a DJ setup and use it on full power, you'll probably blow them up.
So what is the optimal impedance? Headphones that will be used to listen to audio from a portable player or laptop should ideally have a resistance of about 16-20 Ohms and a sensitivity of at least 100 dB/mW. If your device meets European standards for maximum volume, it is best to choose headphones with an impedance of 16 Ohms, since in such devices maximum power even less than in the others.
It is important to consider the impedance of headphones, since all models have to work with different amounts of electrical energy and resistance. Each headphone model is specially designed and calibrated to match specific load volumes. This not only ensures the safety of using the equipment, but also extends its lifespan.
Previously, in the 60-80s, high impedance headphones were often used, since the output energy of devices of that time was extremely high. Then resistors began to be used to reduce the output voltage. In 1996, a standard for headphone impedance was set at 120 ohms. This had a significant impact on the production and development of high impedance models, but at the same time slowed down further development in other directions. Mass sales began in 2009 iPods, as a result of which low-impedance equipment gained high popularity. Therefore, the development of low-impedance headphones has received a new impetus.
So, impedance is one of, if not the most, but still important characteristics of headphones. The model you select must match the audio equipment you use to achieve maximum quality sound and ensure stable normal operation. Therefore, you should pay attention to the impedance when buying headphones and select the most suitable model to avoid rapid wear and deterioration in performance.
