Frequency Response (7.53) 
Frequency response refers to how accurately the media player will emphasize any given frequency. Unlike the headphones, where sometimes you want a dynamic response, with media players you always, always want 100% accuracy. In the graph at right, the left channel is the red line, the right channel is the green line, the vertical axis is the decibel of emphasis, and the horizontal axis runs through the gamut of frequencies we tested. The ideal frequency response would be two horizontal lines that are completely overlapped.
As you can see, the left and right chanels are very close to overlapping, which is good: it means one channel won't be markedly louder than the other. The line is not flat, however. Note how the response gets a bit wavy towards the end. This is a great frequency response, but it isn't perfect.
Distortion (2.08)
Distortion refers to any difference between the original sound file and what the device actually outputs. On the graph to the right, the left channel is once again red and right is green. The numbers on the left represent the percentage of distortion. Anything close to 3% distortion is noticeable and bad. Distortion can be caused by over-worked amplifiers or some sort of digital-to-analog problem among other things.
The E100 had a bit of an issue with distortion. Typically we see less than 0.5% distortion, but here we see about 2.5% distortion. Now, 3% distortion is annoyingly noticeable, so 2% is not good.
Crosstalk (7.95)
Crosstalk refers to the left and right channels' tendency to bleed over into the other. Ideally, sounds broadcast over the left channel will only be heard on the left channel, while sounds broadcast on the right channel will only be heard on the right channel. The ideal graph at right would look like two 100% overlapped lines.
The E100 didn't have a lot of crosstalk. The only bit where they exhibit any crosstalk is a few bits after 1kHz. If the device had poor crosstalk, the lines would jut off in different directions.
We measured the crosstalk at about -66.7 decibels. This is more than the iPod Classic's -104dB, and less than the Archos 7's 65.2dB. Most users wouldn't be able to notice these crosstalk levels.
Output Power (6.13)
Media players need power to boost volume or drive headphones. Since some headphones have a big impedence, meaning they require a lot of power output to function. High impedence plus low output power means there won't be enough power left to allow for a high volume.
The E100s had good output power, but it should be fine for most users. We were about to get 24.5 milliwatts out of the E100. The Archos 7 was able to get 4.6 milliwatts, which was terrible, the iPod Classic was capable of 29.5 milliwatts, and the Shuffle could output 18.6 milliwatts. The E100s are towards the high side of this spectrum.
Noise (9.58)
Noise refers to any sound the device adds to your music that isn't supposed to be there. Most noise is caused by the device's circuitry crackling with electricity, but noise can also be caused by a bad connection, faulty wiring, or other problems. It's impossible for 100% noise-free playback, but the E100 does a pretty good job. The small amount of noise it produces will be completely overshadowed by your playback.
Included Headphones (3.12)
The E100 is at the lower end of mid-range devices, and it's headphones are typial pack-in affairs. They had an erratic freuqency response with poor bass. Their distortion levels were significantly higher than the average set of entry-level headphones. Since their ear buds rest ouside the ear canal, they don't block out much sound at all. They weren't capable of a particularly high decibel-free output, likely due to their high distortion levels to begin with.
All in all, the E100 does nothing to sway us from our recommendation that you never use packaged-in headphones.
These things are pretty bad. Buy real headphones.
|
