At what point do you want to add a headphone amp?

Discussion in 'Audio/Video & Home Theater' started by cmdrdredd, Nov 9, 2012.

  1. cmdrdredd

    cmdrdredd Lifer

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    How does one exactly determine when they might need a headphone amp to get the most out of their cans? If there a certain ohm rating that would be considered too high to drive from standard equipment?
     
  2. sdifox

    sdifox No Lifer

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    Impedance of the headphones.

    wikipaste

    Headphones are available with low or high impedance (typically measured at 1 kHz[dubious – discuss]). Low-impedance headphones are in the range 16 to 32 ohms and high-impedance headphones are about 100-600 ohms.[5] As the impedance of a pair of headphones increases, more voltage but less current is required to drive it, and the loudness of the headphones for a given voltage decreases. In recent years, impedance of newer headphones has generally decreased to accommodate lower voltages available on battery powered CMOS-based portable electronics. This results in headphones that can be more efficiently driven by battery powered electronics. Consequently, newer amplifiers are based on designs with relatively low output impedance.
    The impedance of headphones is of concern because of the output limitations of amplifiers. A modern pair of headphones is driven by an amplifier, with lower impedance headphones presenting a larger load. Amplifiers are not ideal; they also have some output impedance that limits the amount of power they can provide. In order to ensure an even frequency response, adequate damping factor, and undistorted sound, an amplifier should have an output impedance less than 1/8 that of the headphones it is driving (and ideally as low as possible).[6] If output impedance is large compared to the impedance of the headphones, significantly higher distortion will be present.[7] Therefore, lower impedance headphones will tend to be louder and more efficient, but will also demand a more capable amplifier. Higher impedance headphones will be more tolerant of amplifier limitations, but will produce less volume for a given output level.
    Historically, many headphones had relatively high impedance, often over 500 ohms in order to operate well with high impedance tube amplifiers. In contrast, modern transistor amplifiers can have very low output impedance, enabling lower impedance headphones. Unfortunately, this means that older audio amplifiers or stereos often produce poor quality output on some modern, low impedance headphones. In this case, an external headphone amplifier may be beneficial.

     
  3. sygyzy

    sygyzy Lifer

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    What is your source? What kind of headphones are you using? Reply back and we'll help you.
     
  4. uhohs

    uhohs Diamond Member

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    impedance and sensitivity

    what headphones do you have or are considering?
     
  5. cmdrdredd

    cmdrdredd Lifer

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    It is just a thought I had. I see some talk around forums where people use headphone amps and I wondered how you actually determine if the amp will help. My headphones don't warrant an amp (sennheiser pc360, Sony mdr-7506 is what I have at home and klipsch s4 for on the go). I was just trying to satisfy my curiosity on when an amp becomes necessary.

    I assume if I was using some high end Grado or maybe higher end Sennheiser headphones I would, generally speaking, benefit from an amp though correct? Assuming of course I have a high quality source (i.e. not the radio or mp3s).

    The benefit or necessity of a headphone amp is just something I was curious about.