Treble Click: Headphones: Quick guide to dB, Ohm and Hz.

What ind of Headphones / Ear Buds should you buy?

Let's simplify all the information related to Ohm (Ohms), dB (Decibels) and Hz (Hertzs). There is a lot of technical information around the Internet trying to explain what they are, but they don't answer the quick, frequent question of what should I take into account when purchasing a new set of headphones?

TrebleClick aims to make your life easier, so we're going to simplify all that, and explain it in an easy-to-understand way:

Ohm, dB and Hz: what they are, what's their purpose, and why are they important?

Ohm: Ohms are the Impedance of your headphones, or, in plain English: the resistance that your headphones oppose to the flow of an electric current. This determines the amount of power that reaches your headphones, in relation to the amount of power sent. More Ohms will require a higher power input value to work properly. If the resistance value is very high, your system will need an amplifier. You will find the nominal value of resistance in the technical specifications of your headphones. 16, 24 or 32 are usual Ohm values, and they should work for regular purposes.
dB: The Decibels represent the Sound Pressure Level (SPL), or the audio volume power. Higher dB values will make the sound in your headphones be louder. But higher dB values will also lead to earlier distortion in such sound. The higher this volume value is, the closer to the distortion threshold you'll be.
Hz: Hertzs are the Audio Frequency, and they actually are the most important parameter to take into account when considering the sound quality of some new headphones. The Hertzs represent the frequency range that your headphones will play back, from the lowest bass to the highest treble. This usually comes specified in minimum and maximum values, so the best headphone sets will have broader ranges, with a lower minimum, and a higher maximum. Human ear can hear sound frequencies ranging between 20 and 20.000 Hz.

Conclusion: what do I need in my headphones?

If you are a professional sound technician, or an expert, and you already have a pretty decent sound system, you won't probably even need to read this, and you may even disagree about some details. But if you are just an average computer user, avid gamer or designer, and the only thing you want is some headphones to use with your computer or laptop, the only things you need to take into account when choosing them are as follows:

A higher dB value implies higher sound volume. The usual values are set around 112 dB/mW.
Higher Ohm mean higher resistance values, and this means that you'll need higher input power values - otherwise, you'll experience a lower sound volume. Nominal Ohm values of 16, 24 or 32 are the most frequent ones.
A higher Hz range will play more sound frequencies, providing higher quality sound playback. This is the other key parameter. 20-20.000 Hz is okay. From that point on, a broader frequency range (like 12-28.000 Hz) should have better sound quality, while a narrower frequency bandwidth (for example, 21-18.000 Hz) would provide lower sound quality.