Frequency range is a sign of the amount of music that can be heard, in relation to the layers of sound. If you are serious about your music, then the recommended frequency range is generally 10Hz to 25,000 Hz. When looking at the frequency range of any set of headphones you should also be aware of the sound, or frequency response, curve. The curve indicates which musical elements will be more apparent to your hearing. If you are looking for a sound that emphasizes bass, then you want the lower frequency end of the range to be high on the curve. Where there is a U shaped curve, the mid-range sound is cut out. If you prefer headphones that do not emphasize any specific range, you need headphones that provide a flat response.
Understand the Importance of Impedance
Impedance is normally associated with speakers and amps, but it is just as important when it comes to headphones. Impedance is measured in ohms and relates to the rating of the amp, or audio equipment, and the speakers used to listen to the sounds. If the ratings are incompatible, then damage can occur to your amp, or other audio equipment. It will also affect the quality of the tone of the sound you are listening to. The impedance rating of your headphones needs to be the same as that of the audio equipment being used in order to achieve optimal sound quality.
Over-the-ear headphones with Open Backs – these headphones do let more sound into the headphones, and from the headphones into the surrounding area. The benefit of this is that there is less distortion because of the lack of plastic casing. The sound of music heard through this type of headphones tends to be more natural. Another benefit of these headphones is that they are generally more comfortable to wear over extended periods of time.
The quality of sound isolation present in a set of headphones can be tested quite easily. Wear the headphones, without music playing, in an area that contains background noise. The less external noise that you can hear, the better the superiority of the sound isolation.