SHURE E4 High Performance Earphones

Personal Fit Kit
Several options are provided with the E4 earphones and include a pair of disposable foam sleeves, a pair of triple flange sleeves, three pairs (small, medium, large) of flex sleeves, and three pairs (small, medium, large) of soft flex sleeves to ensure the best fit possible. Some performers may choose to mate the E4s with sleeves prepared by a professional audiologist which provides the ultimate custom fit for both performance and comfort. A pair of replaceable nozzles are also included in the event the original ones become clogged with ear wax. The gold-plated 1/8" stereo plug makes it compatible with other personal audio products such as iPods. An 1/8" to 1/4" plug adapter is provided for the more common professional audio interfaces. The supplied in-line attenuator can be used on airplanes and other applications where high level signals need to be reduced. A zippered nylon carrying case holds the earphones and sleeves.

Impedance
The impedance of the E4 earphones gets interesting as it approaches the high frequencies. We measured 27 ohms at 1kHz which is close to the specification of 29 ohms. A peak of 44 ohms occurred at 2kHz and then the impedance steadily increased to 1380 ohms at 20kHz. The overall impedance of the earphones is relatively flat up to 12.5kHz and then begins to rapidly increase with frequency. We saw similar characteristics with the E3c earphones, but to a lesser degree.

Performance
The performance of the Shure E4 earphones is a step up from their E2 and E3 models. The internally ported enclosure helps with extending the low-frequency response. The midrange was detailed and the high frequency response was excellent. While the flex and flanged sleeves offer the most comfort, the foam sleeves provide the best performance due to the way they seal in the ear canal. These are similar to the ear protection ear plugs used in industrial environments. Simply squeezing them and placing them in the ear allows them to expand to form a custom sonic seal. Like many of the other in-ear designs from Shure, these earphones need to be well sealed in the ear canal to maximize audio performance. Shure sells additional disposable foam sleeves in bags of 20 (PA750) and bags of 500 (PA754).

These earphones have been with me on several coast-to-coast business trips and they never let me down. More recently my plane seat was right next to the large jet engine on an MD-80 and I had to rely on the E4 earphones to not only block out the majority of the noise, but to also provide me with high quality audio from my portable Neuros digital audio player. It's no wonder why these earphones work so well with performers on stage where its audio performance finds its way through the loud background noise.

Conclusion
The new SHURE E4 earphones fill the performance/price gap between the E5 and E3 earphones already offered in the E Series lineup by providing excellent audio performance along with the ability to seal out unwanted background noise. Users will enjoy the lightweight design and sturdy cable construction. The wide variety of different size in-ear adapters included with the earphones maximize comfort and provide peak performance. The problem for me is that I have become so dependent on these earphones when I travel, that they are as important as my shaver.

- Kevin Nakano