A. It depends. Noise-cancelling headphones use active technology to play unique frequencies that block outside noises, and depending on which model you buy, the battery can last anywhere from 15 to 40 hours. If you’re using a set of wireless headphones, the battery will be used for both noise cancellation and wireless connectivity, so expect the battery to deplete faster if you’re using both.
That depends on what you’re using them for and how much you’re willing to spend. At the high-end, over-ear and in-ear headphones can both perform fantastically. For those of us not willing to spend thousands on headphones, over-ear headphones typically offer better bass response and a bigger soundstage, but in-ear headphones are significantly more portable and convenient — especially wireless earbuds.
Wired headphones are attached to an audio source by a cable. The most common connectors are 6.35 mm (¼″) and 3.5 mm phone connectors. The larger 6.35 mm connector is more common on fixed location home or professional equipment. The 3.5 mm connector remains the most widely used connector for portable application today. Adapters are available for converting between 6.35 mm and 3.5 mm devices.
Expensive: Audiophile-grade headphones can cost anywhere between $130 and $2,000. Headphones in this price bracket are no joke: they create impressive soundscapes, are robust enough for use in a recording studio, and they’re just plain beautiful. If you need a pair of headphones for critical listening, or you simply want the best headphones around, it’ll cost you.
Frequency response: Frequency-response specifications in full-size loudspeakers are generally pretty useless in predicting sound quality, but headphone frequency-response numbers are even worse. Manufacturers have routinely exaggerated frequency-response figures to the point that they're irrelevant. Even the flimsiest, cheap headphones routinely boast extremely low bass-response performance --15Hz or 20Hz -- but almost always sound lightweight and bright. Generally, bass buffs will be happier sticking with larger 'phones.
The impedance of headphones is of concern because of the output limitations of amplifiers. A modern pair of headphones is driven by an amplifier, with lower impedance headphones presenting a larger load. Amplifiers are not ideal; they also have some output impedance that limits the amount of power they can provide. To ensure an even frequency response, adequate damping factor, and undistorted sound, an amplifier should have an output impedance less than 1/8 that of the headphones it is driving (and ideally, as low as possible). If output impedance is large compared to the impedance of the headphones, significantly higher distortion is present. Therefore, lower impedance headphones tend to be louder and more efficient, but also demand a more capable amplifier. Higher impedance headphones are more tolerant of amplifier limitations, but produce less volume for a given output level.
A: Absolutely not... unless you're just looking for an excuse to try something new. But if you're not made of money, you can always hit up the manufacturer for a pair of replacement tips. Most earbuds only come with one set of each size, so losing one can be annoying. If you're in an experimental mood, Comply offers aftermarket tips that fit your brand and come in a variety of materials.