It’s a fact, a good pair of headphones costs significantly less than a good pair of speakers. But like speakers there are literally hundreds to choose from, ranging in price from next to nothing to ridiculously expensive. This article offers a few basic guidelines for choosing headphones.
Hi-fi or Monitor Headphones?
There are two basic categories of headphones: headphones for regular listening, which for the purpose of this article I’ll refer to as hi-fi headphones, and monitor headphones, designed for use in studios or other professional sound environments. Monitor headphones tend to be a little more robust, some have easily replaceable parts and detachable cables, and all aim to have as flat a frequency response as possible within their cost and design constraints. A flat frequency response is good for hearing details in recordings, but for general listening hi-fi headphones are preferable.
Some cheap monitor headphones only qualify as monitor headphones on the grounds that they have a closed-back design (see the next section), making them suitable for use in noisy environments. Others might adopt the term ‘monitor’ to suggest studio quality. However, don’t be fooled. True studio monitor headphones would not fall into the ‘cheap’ price category.
Open, Semi-open, or Closed-back?
After deciding whether you need monitor headphones or hi-fi headphones the next consideration is the design type, which falls into three basic categories: open-backed, semi-open, and closed-back.
Open-backed headphones (pictured above right) often sound more open and natural than closed-back headphones. The down side is they offer less isolation and allow more sound spill. In other words they let room sounds in, and whatever you’re listening to out, more so than closed-back headphones. They can also sound a little light, certainly at the cheaper end of the spectrum.
Closed-back headphones (pictured below right) are good at keeping the sounds you’re listening to in, and extraneous noise out, and are therefore recommended for listening environments where the background noise is relatively high. But closed-back headphones can sound boxy, as the sound bounces around inside the cup, and more coloured than open-backed designs. However, the more expensive closed-back headphones I’ve listened to sound very good, and not boxy at all.
Semi-open designs are not quite as common. They give some of the benefits of open-backed and closed-back together by offering a certain degree of isolation while still sounding open and natural.
Circumaural or Supra-aural?
Another design consideration is whether to go for headphones that fit over the ear (circumaural), pictured far left, or headphones that sit actually on the ear (supra-aural), pictured near left. This is a matter of personal taste but having used both I have no preference. I would simply choose the ones that sound the best. One disadvantage of circumaural headphones is that, depending on the type of material used for the cushion that goes around the ears, they can make your ears hot. Fabric cushions are probably better than vinyl cushions, but they tend to perish after a number of years. It is possible to replace the cushions on some of the more expensive headphones but it isn't cheap, especially if the headphones have to be sent back to the manufacturer. However, it's sometimes possible to buy just the cushions and fit them yourself.
Most headphones claim to reproduce a full 20-20,000 Hz to accommodate the spectrum of human hearing. Any frequencies outside this range are inaudible, at least to humans. However, the frequency response figures given with headphones are largely meaningless unless the manufacturer supplies a graph or gives parameters for the measurement (e.g. ±3db), which many manufacturers don’t. And even if a graph is available it can only give a mild indication as to how the headphones will sound. The best test is to listen to them.
Some manufacturers specify the power handling capacity, but not all. For those that do, figures usually lie between 100 mW (milliwatt) and 1,000 mW. How this sounds, in terms of volume level, depends on the efficiency of the driver (the little speaker in the headphones), and the impedance. As a rough guide I would say on average 100 mW is quite loud, and 1,000 mW would damage your hearing within a very short period of time.
Impedance, measure in ohms (Ω), can cause a lot of confusion. The majority of headphones fall somewhere between 32Ω and 600Ω, but what’s the main difference? I think it’s true to say that most devices will work fine with headphones in this range. Theoretically, all else being equal, headphones with higher impedance, such as 600Ω, will sound quieter than headphones with lower impedance (if the volume control isn’t adjusted to compensate). However, unless you know the device you are going to be using the headphones with has a low power headphone output (some camcorders and cheap mp3 players may fall into this category) there is no reason to let the impedance influence your decision on which hi-fi headphones to buy. Most modern audio devices (CD players and amplifiers) will drive any headphones within the stated range, to uncomfortably loud levels.
As for monitor headphones being used in a studio, higher impedance headphones will be better if you plan to run more than one pair from the same output source. This is because two pairs of 300Ω headphones, for example, when connected together in parallel will present a 150Ω load to the headphones output. Normally this shouldn’t be a problem, but check with the instruction manual to confirm that 150Ω falls within the specified impedance range. Connecting two pairs of 16Ω headphones together results in an impedance of 8Ω, which could result in overloading the headphones output. Again, check the specifications of the equipment being used to see if it falls within the specified impedance range.
Headphone cable can be straight or curled. If you accidently have your foot on straight cable when you stand up the headphones will be yanked off your head with force, possibly causing damaging. With curled cable you will feel a gradual increase in tension before the headphones are torn away from your head. Other than that I can't think of any advantage of one against the other. Additionally, cable can enter the cup of the headphone at either one side only, or both sides. I have used both variations and have no preferance.
The strength of the headband is worth paying careful attention to. If it feels a little strong when you first try the headphones on, there’s a danger that wearing them for any length of time could be fatiguing. If the band feels too slack, and the headphones don’t stay in position, then it’s best to check out a different pair. Headphones slipping out of position, or falling off every time you move your head, don’t add anything to listening pleasure.
As mentioned earlier, the price of headphones varies enormously. As with many things, you get what you pay for so my advice would be to get the best you can afford, but with one proviso. Unless you intend upgrading your equipment it’s best to match the price of headphones to the equipment you are using. The adage ‘A chain is only as strong as its weakest link’ comes to mind. If your mp3 player cost £100, then buying a £300 pair of headphones is going to be of no benefit.
On the subject of mp3’s, since most mp3 files are compressed, and at 128 kbps you’re only hearing a fraction of the audio compared to a CD, buying expensive headphones is pointless. You would be paying for headphones that are capable of reproducing detail that is simply not there in an 128 kbps mp3!
Investing in a good pair of headphones is well worth it as, like speakers, providing that they are looked after they will last many years. Find a store with as large a variety as possible in stock, travelling to a larger town or city if necessary, and spend some time auditioning.
My final advice would be to buy a reputable brand, if possible audition the headphones with music you are familiar with and, most important of all, use your ears to decide which headphones sound best to you.
Below I have listed some related articles and useful links.
Useful external links:
These links are provided for your reference only. I have no connection with these sites and cannot take responsibility for their content.
For more technical information on headphone impedance check out this site.