Categories: Machinery

What is affected by the resistance in the headphones and what is the impedance

With the rapid development of information and communication technologies, you can increasingly see a man with headphones in the subway, ??on the street, home. If they were originally used for radio communication, then later the audio device became a mass medium of information consumption. To choose the most suitable headset for your smartphone or tablet, the user needs to understand the basic characteristics of the device. Before you consider, what and how the resistance in the headphones affects, let's understand, what is impedance. Knowing this information, it is possible to extend the service life of the equipment.

What does "impedance" mean

The impedance in the headphones provides resistance at the input. Operational and technical properties of portable devices for listening to sound depend on this characteristic. To find out, how much technique requires an amount of energy to ensure good sound, this parameter is specified in the passport of portable devices.

The unit of electrical resistance of the conducting element - Ohm.

For pocket audio players, modern smartphones fit headphones with a nominal resistance 16-40 Ohm. This value provides a high sound of the device at a low level of output signals. When connected to a headset with standard sound cards with the use of special amplifiers choose an audio device with high impedance parameters - 120-150 Ohm. Devices with high-resistance electrical resistance are suitable for professionals, working on special equipment, having a high level of output voltage.

Varieties of equipment depending on the values of resistance

In the market of multimedia equipment, manufacturers offer a wide range of different devices with different technical characteristics: sensitivity, impedance, frequency range. Based on that, which the headphones resist, there are two types of equipment: high-resistance and low-resistance devices. For full-size and in-channel headsets, the parameters of the separation boundaries are different.

Low-impedance headset devices, the impedance of which for in-channel devices is not more 32 Ohm, for full-size - no more 100 Ohm.
High-impedance devices - impedance of which for in-channel devices is more 32 Ohm. For full-size values should be greater 100 Ohm.

Impedance curve for different types of devices

Consider, what information is given by the graph of frequency dependence within 20 to 20000 Hz of resistance for different types of devices.

Dynamic full-size headset. For this type of technique, the impedance curve is not straight, and with small sections of rises at high and low frequencies. If the resistance for dynamic headphones is specified 32 Ohm, then in reality at certain frequencies the multimeter can show values two to three times higher.
In-channel devices. For this headset on the graph at standard values (16, 24, 32 Ohm) deviations are not detected. The impedance curve on the graph for this type of headphone is a horizontal straight line.
Orthododynamic and isodynamic equipment (example, HiFiMan, Fostex, Oppo) have a straight line impedance. However, some models in local areas at ultra-high frequencies have some changes.
In-channel armature headset. For most single-driver devices at high frequencies, the impedance graph increases, so the headset gives a "clear sound" without distortion.
Multi-driver and hybrid headphones. The impedance curve in these headphones at higher values 500 Hz behaves unpredictably - periodically striving up or down. The drawdown of real resistance decreases to 4 Ohm at the stated 100-ohm on 1 kHz.

Based on the impedance curves, it is seen, that the stated value in the headset is different from the actual values.

Optimal impedance values for use with different devices

To buy devices with a good range of sound reproduction, the value of resistance must be taken into account. The sensitivity of devices with high resistance is less, than in low-impedance models. Therefore, the battery life of technical devices when using headphones with different resistance does not match. Consider the optimal values of the level of voltage consumption for different devices.

Smartphone. Nominal resistance for the best sound of headphones will be low-impedance (example, 22 Ohm). In this case, the device, in addition to good sound, will consume more electricity. So that you can play music on your smartphone for longer, choose a 32-ohm model. When using iPhone devices, models with standard audio frequency bands are suitable 22-32 Ohm. It is not advisable to use headphones-monitors without auxiliary accessories: portable amplifier, audio player with a powerful sound card.
Player. The most optimal headphone resistance for a standard device - 16 Ohm. If the audio players have a more powerful output (Hidisz or iHiFi), which provides a higher voltage level 200 mV, choose less sensitive devices with resistance in 32 Ohm. Such devices reduce power consumption and increase battery life.

The following points are taken into account when choosing listening equipment:

in reality single-driver reinforcement devices (Grade GR10, different Klipsh models, Etymotic) have an average resistance above, therefore, audio players and smartphones work with them for a long time without recharging;
multidriver dynamic and reinforcing equipment has a lower average resistance, so smartphones or players operate without recharging for a short time.

Portable amplifier for optimal sound

High-impedance headphones are used not only by professional musicians, but also simple music lovers. That the music was listened to with sufficient volume, you need to match the power of the speakers with the device. In this case, absolutely all frequencies are reproduced, and the sound is high quality. The portable headphone amplifier helps to solve this problem - it provides high accuracy of sound reproduction.

The principle of operation of the amplifier is as follows: due to the high value of the impedance in the headphones, the device emits less current, which prevents frequency distortion of individual stages. High-impedance headset has uniform amplitude-frequency characteristics due to the use of an amplifier.

To avoid deterioration in the quality of headphones and their rapid wear when buying equipment pay attention to the impedance. Which is better depends on the devices, with whom they will interact. This setting should match the model of audio equipment and listening devices. Resistance for different types of headphones affects the sound quality and ensures stable operation of the audio device.

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