Sep 25, 2012 3:44:03 PM
While choosing a headphone, one just doesn’t look into the looks and feel of it. There are other more subtle electrical nuances that need consideration. The fact is, when it comes to electrical intricacies, most of us are complete laymen. Yet we need to look into certain details before choosing the best headphone. One of the specifications that need looking into is the headphone impedance.
Impedance. What is that?
The electrical definition means the amount of resistance that is offered to alternative current while moving through a circuit. The voltage created from power source tries to force the current through a circuit. This current faces resistance in its course from one terminal to other. This very phenomenon is termed as impedance. It’s measured in ohms named after George Ohm, the German physicist.
To make the understanding simpler we can compare electrical impedance to water coming out of a hose. You may have noticed that narrow hoses drain less water. The reason is narrow hose mouth offers more resistance (impedance in this case) to the flow of water. Thus if we denote water pressure as voltage and water as current, the impedance scenario gets pretty clear.
You may ask how that affects headphone audio. Impedance doesn’t affect the “quality” of audio. It does affect the loudness or level of sound though. To get a clear picture we must delve a bit deeper in the physics of headphones.
Headphone Impedance: A Deeper Look.
The relation between impedance and sound level is inversely proportional. The more the impedance is, the lesser current goes in, resulting in lesser power for the headphone to function. The lower impedance acts just the opposite way, it drives more current to the speakers, resulting in louder audio in a certain voltage.
The amplifier in use also plays a part as they have their output impedance too. What that means in general is some power is lost from the amplifier itself. That’s the reason why low impedance amplifiers go great with low impedance headphones. If one pairs a low impedance headphone with powerful amplifiers, there is a possibility that it'll just "blow out".
Does that mean lower impedances are better? The views vary depending on the sound system. Nowadays headphones come with lower impedance of around 25 ohms or less. Thus they need lower voltage to run and works well with devices with weak amplifications. Devices like portable music players, phones, etc. High end headphones like the ones that DJs sport needs more power to operate. DJ headphones are paired with DJ mixers and use much powerful amplifiers. Thus they need a higher impedance of around 25 to 70 ohms. The difference between lower impedance and higher impedance headphones doesn’t end there. Let’s have a look at it:
Low Impedance Vs High Impedance:
Low impedance - Low impedance headphones works well with devices with weak amplification. They need considerably little power to deliver higher audio levels. This is good news for people going for cheaper headphones.
High Impedance - The high impedance headphones require more power to deliver high audio level. Thus they are more apt for high end audio setups.
Low impedance - Lower impedance means they are more susceptible to buckle under higher load.
High Impedance - High impedance headphones can sustain more current load. Thus they are more protected from damages caused by overloading.
Low impedance - Low impedance headphones works well with portable music players, phone, etc.
High Impedance - The high impedance headphones, thanks to their overload protection are compatible with a wider range of audio setups.
Low impedance - Low impedance headphones tend to be louder even in lower voltages. But they need better amplifiers to achieve that.
High Impedance - The high impedance headphones are more versatile and compensate amplifier limitations. They are more true to the original audio input, maintaining audio fidelity in the process.
In a nutshell, the impedance rating of headphone does play a role is choosing the right headphone for specific use. You won’t want to be in a position where you select a headphone that neither matches your audio setup nor gives you optimum performance.
Better take note of seemingly complex issues like impedance before choosing the best headphone.