Close Back Design
Photo by Alex Holyoake on Unsplash
Of the two types of headphones design, the most popular is closed-back headphones but that doesn’t make better just different with its own application. One of its key feature is having a closed enclosure over the driver thus sealing the sound reproduced between the headphone and ears. They offer great sound isolation both from background noise entering the ears from the outside world and vice versa sound being leaked out by the headphone. Good in noisy environment and when listening to music without disturbing others in the vicinity. Due to the closed-back nature of these type of headphones, bass frequencies can be somewhat exaggerated but not always, good for bass heavy listening or bass head but not for the discerning listeners or audiophile at heart.
Open Back Design
Open-back versions of headphones are exactly that, with allowing air to travel through the headphones giving it a more lively sound reproduction and somewhat wider soundstage. Frequencies and musical notes aren’t exaggerated but more natural. With all of it’s advantages, it’s not a headphones for noisy environments or listening to music next to another person. As the headphones lets air pass through, it also let sound out as well.
- Choosing between an open-back or closed-back headphone, one should look at the application, where and how the headphones will be use as well as the overall desired listening outcome. It is very much a personal decision.
It’s the measurement of sound ranging from low frequencies to high or bass to treble and anything in between of a headphone capability. It’s measured in Hertz with the following figures normally spec out - 20Hz - 20,000Hz or 20Hz - 20KHz.
The lower figure of 20Hz is for bass ranging to the higher frequencies towards 20KHz for treble and sibilance.
Generally speaking the lower the number, the more bass or the lowest of frequencies the headphone can reproduce. The higher the frequencies are, the more detail it can showcase.
Now that was reasonably sweet and short of an explanation.
Photo by Blaz Erzetic on Unsplash
If you’ve ever picked up a headphone box, and read the specifications own the box, one of the thing you would have seen is “impedance”. Impedance is the resistance of the driver / transducer to electric current and that’s about how far technically we’re covering this topic. It’s about understanding the numbers that relates to impedance. All headphones have an impedance figure, some low and other high. This isn’t about the larger figure being better but more about the headphone usage and what devices it is connected to.
Most headphones carries an impedance figure ranging from 8 to 600 ohms. Imagine a smartphone playing music where you have two identical headphones, one with a 32ohm impedance and the other with a 250ohm, the one with the higher ohmage is said to have the greater resistance. The greater the resistance, the lesser the electric current, the lesser the volume.
If we wanted to play music at the same level using the smartphone with the 250 ohm version then we would need to use an external amplifier to boost the signal from the smartphone to the headphone.
- 32 ohm - good for portable devices (smartphones or digital audio players - DAP)
- 33 to 100 ohm - better with a smaller headphone amplifier or higher end DAPs
- 100 to 600 ohm - dedicated amplifiers to get the most out of the headphones
Note - its about matching the right headphone impedance with the output impedance of the device it’s connected to. As impedance rises, bigger more powerful amplification are required.