When buying a pair of headphones, especially in today’s time when getting knocked over by the hype train is easier than ever, you need to be extremely vigilant. There are things that are actually not what they look to be. For example, Apple Music supports playing lossless audio using the ALAC CODEC, but Apple’s own AirPods do not support that CODEC. While it is very hard for untrained ears to distinguish between certain types of audio transmissions, having them ready and eventually training yourself to be able to distinguish between them is nice to have. And, especially when high-end audio products like headphones and earphones are available in plenty, you’d not want to spend a fortune for something that you could get for half the price just because the pricier product was marketed to look fancier. So, to help you map your way through the world of headphones [over-ear and on-ear] and earphones [in-ear], we have some tips and words of caution coming from our audio experts laid out here. Read on –
Diagrammatic representation of a headphone driver
A lot of manufacturers these days advertise the presence of multiple drivers in their earphones. While it may seem like the higher the number of drivers, the better the earphones would sound. However, when looking at the inclusion of multiple drivers scientifically, it is not always the case.
You’d know sound signatures are generally divided into three broad frequency Ranges – lows, mids, and highs. Each of the individual frequency bands have their own frequency values. In the simplest words, these denote the number of vibrations that are there in the waveform of the sound wave produced at that frequency. These vibrations are produced by the diaphragm of the speaker that is baked into your earphones or headphones.
So, ideally, in the case of earphones with multiple drivers, the load of frequency reproduction is taken from one driver and distributed amongst three drivers. This means that each of the drivers is responsible for producing only one range of frequencies, which, when all put together, form a coherent audio signal that your brain interprets as a song or whatever. The process of making sure that one particular driver is producing a given range of frequencies is called tuning.
Tuning is a very intricate process which requires a lot of research and expertise. This means that if the drivers, even if there are many of them in a single earphone, are not tuned to reproduce individual frequency ranges, you might get a loud audio signal, but it may not be accurate. There are several factors contributing to it, but we won’t go in-depth about that over here.
The bottom line is that when buying earphones with multiple drivers, make sure that they are tuned well, and to check that, you will need to experience the device in person. When doing that, you can play a sound frequency sweep that covers frequencies between 20Hz and 20,000kHz, using the device you will use with the earphones and test whether the earphones are capable of reproducing the entire audio spectrum or not.
You’d have read in the last section of the article that the tuning of the drivers is important. But what does it mean? We did cover it in brief over there, but here’s an in-depth look into driver tuning.
So, as we said, tuning a headphone/earphone driver means the calibration of the driver to reproduce certain frequencies. And this varies across manufacturers. One manufacturer might tune their drivers to produce lower frequencies better than the mids and the highs, making the sound bass heavy. The others might have tuned their drivers to give a V-shaped sound signature, where the lows and the highs are boosted, with the mids being lowered.
This shows that, unless tuned with precision and care, two drivers of the same specification will not sound the same. That is why we run multiple tests and take the help of an application and special hardware, instead of just looking at the specifications sheet. And so do you. Yes, the size and materials of a driver will affect the way it sounds, but at the same time, the tuning will also have an impact on the overall sound signature and performance of the device you are getting.
You might have seen studio-grade headsets and regular consumer headsets from the same brands being sold and marketed differently. Right? This is because of the tuning and sound signature of those headsets. Studio grade headphones, despite having the same drivers as consumer-grade headphones, would be tuned to have a flat response. Meaning that across frequencies, the levels would be the same, ensuring that every element of the track or whatever is being worked on reflects as it was recorded.
Consumer grade headphones, on the other hand, will have some colouration in their audio, meaning that the manufacturers would boost certain frequencies to make the overall listening experience more pleasurable listening experience. And, the pleasurability of the listening experience, as we may call it, varies from consumer to consumer. So, we’d again recommend you to look out for your own preferences by trying out the headphones or earphones you are planning to buy.
Don’t worry we did not trick you into reading our rant about programming. This is about the signal transmission that takes place between your audio output device and your source.
If you have dug deep enough into the spec sheets of modern headphones and earphones, you would have seen that some of the manufacturers list the CODECs that are compatible with their devices. CODECs, in their essence, indicate the quality of the signal that can be potentially transmitted via Bluetooth to your audio device and whether or not that device would be able to convert that incoming signal into audio waves or not.
As you would have guessed, across the board, there are many types of CODECs. The most basic and common one of all is SBC. It demands the least amount of processing power from your devices and consumes less power as well. While it does come out to be the lossiest of all, its implementation by manufacturers can define the way it can perform.
Generally speaking, you should avoid going for this, but if you are using your headphones in noisy environments, without ANC, or are using a pair of headphones or earphones that are not properly tuned, then you won’t even notice the difference in quality as you move higher in the CODEC spectrum. The audio signal being pushed by your streaming service, the capabilities of your smartphone all come into play when you are listening to the audio on wireless devices. In the case of wired headphones or earphones, you need to look at the capabilities of your output port.
Most mobile devices these days lack a headphone jack, so in order to get lossless audio output from your phone, you might need to get an external USB DAC specially made for mobiles. As for PCs, you will read more about buying additional hardware for your computer in our PC components part of the cover story.
To guide you better through the world of audio CODECs, here are brief descriptions of some popular CODECs that are seen in headphones and earphones these days –
| Codec | Supported Bit Rates | Special Features | Downsides | High-res Audio Support |
| SBC | up to 345 kbps (theorotically) | Lower power consumption | Latency issues, compressed audio | |
| AAC | up to 320 kbps | Better compression than SBC | Not in open domain, uses more power and processing | |
| aptX | up to 384 kbps | Better compression algorithm than SBC | Not supported on iOS | Yes |
| aptX HD | up to 576 kbps | Higher bit rate and bit depth than aptX | Not supported on iOS | Yes |
| aptX LL | up to 352 kbps | up to 32ms low latency | Not supported on smartphones | |
| LDAC | up to 990 kbps | Support for high-res audio (better support for Android devices) | Proprietary Sony technology, limited presence in the market | Yes |
| ALAC | up to 1411 kbps | Supports lossless audio | Limited to Apple devices | Yes |