Amplified
Headphones – When Do I Need
Them?
Some people ask "I have a portable mp3 player, so do I need
amplified headphones"? To answer that question, there are
many applications where you need some help from an amplifier.
The new mp3 players, especially ones that run on one AAA
battery don't have a whole lot of output power to drive
headphones. Typically, they get out of this dilemma by
including very high efficiency headsets. These often sound
really bad, mostly because high frequencies which make the
sound more tinny require less power to reproduce. These mp3
players are totally incapable of driving a good set of
headphones with decent bass response to any acceptable volume
levels. If you buy an external battery powered amplifier or a
pair of headphones with the amplifier built into them, you have
much more flexibility. See, when you put an amplifier in the
loop, you do more than just raise the volume, you bring back
the missing bass.
What other situations might call for amplified headphones?
Well, many computer sound cards have lousy speaker drivers.
They have a low current output. They have a lot of distortion
at higher volumes, over 10%. This distortion becomes very
noticeable unless you are just trying to drown out the noise of
a passing train. Maybe a coworker is the passing train that you
are trying to drown out. Whatever the case, having an amplifier
in the loop can result in high sound levels at very low
distortion. This also brings to mind another reason for having
headsets with amplifiers in them. By having the heavy lifting
done by another amplifier, the device you are listening to can
play without distortion and you can play the music at very high
levels cleanly.
You might be wondering about the extra batteries you'll be
needing. Yes, amplified headphones do need batteries for the
amplifiers in them. Fortunately for you, most of these units
consume very little power. As a result, a play time of over 100
hours is not unreasonable. If you use it for commuting, an hour
a day or so, that's three months on one set of batteries.
That's not bad at all. I personally am a fan of rechargeable
batteries. I usually get two sets so when one set is on the
charger, the other set is on the road with me.
|