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High Impedance Earphone Advantages and Disadvantages

Posted on February 28 2013 by Any amplification circuit has the noise, i.e., when the input terminal is short-circuited, the noise measured with the instrument at the output terminal, it does not substantially change with the volume knob hourly position change in high impedance ceramic earphone, customizable headphones, Audio Headphones

Superiority:



1. High impedance headphone system signal noise ratio is high

Any amplification circuit has the noise, i.e., when the input terminal is short-circuited, the noise measured with the instrument at the output terminal, it does not substantially change with the volume knob hourly position change, in other words, this is a fixed voltage value. Thus, we can simply have results according to Ohm's law:
High impedance: low noise power
Low impedance: high noise power

2. High impedance headphones can to the maximum extent avoid negative impact of the amplifier midpoint DC offset electric potential

The OCL circuit is the mainstream structure of the power amplifier, any OCL is not absolutely zero in its output terminal when the input is zero. Attentive friends will find when you put the high impedance ceramic earphone plug into the amp and turn on the power, you will hear the current impact sound. This midpoint of amplifier is voltage, usually the size is a few millivolts, and I encountered a few ten millivolt offset manifestations. The voice coil of the headset will be slightly offset the initial position of the magnetic gap under the effect of this voltage, which leads to the reduce of effective stroke of the headset, and distortion increase. In the same offset voltage, the voice coil offset of high impedance headphones is relatively small.

3. The same series high impedance version headphones, the voice coil turns are the same but line is finer, the quality (inertia) of the vibration system is reduced, the ability to follow the weak and rapid signal increases. Here, high resistance = high grade.

Disadvantages:



1. High impedance headphones are more difficult to be driven, less matching with portable devices

Portable devices mostly use battery, the voltage is low; taking into account the life time, the output power of the circuit is limited. These conditions determine it is more difficult for the high impedance customizable headphones to play performance on these devices.

In fact, portable devices are the patent of earplugs, almost have no chance with large-diaphragm headphones. The high impedance is not the only factor, not even the most important factor. The headset drive difficulty degree is in turn determined by the following factors:

Diaphragm area, the greater, the more difficult to push
Sensitivity (db / mW);
Impedance
Diaphragm area is ranked first. The impedance plays the role of the " be aiding a tyrant" at best.

2. Number of turns of the voice coil of high impedance headphones is much, fine lines, bringing some negative factors

Due to the number of turns is large, fine lines, voice coil inductance and distributed capacitance rise, it would bring additional distortion to headset system;
Due to the fine line, the manufacturing assembly of the headset is difficult; impedance headphones are prone to have breaking the voice coil leads fault in a wet environment.

www.kinera.cn has been focused on the research and development and product application of audio technology over the years. Now, our core products are mainly MP3 or MP4 headphones, computer headphones, bone conduction headphones, wireless headphones, vibration headphones and moving iron headphones.

This article come from:http://cell.battery-products.com/electronics/high-impedance-earphone-advantages-and-disadvantages.htm
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