Design Article
Ear bud headphones jam lots of complexity in a tiny package
Rich Nass
1/13/2010 11:57 AM EST

I'm not laughing any more. I ran into Paul Manfrini, a director of product development for Logitech a few months back, while he was out showing off one of his latest products—the Ultimate Ears 700 noise-isolating earphones. The ear buds are a hot button for me, as I've been told I have "irregular ears." Before your imagination starts wandering, I'll explain. Most people have an ear canal that goes straight. Mine goes around a curve.
For an ear bud-type headphone, that presents two problems. One is that the sound has to navigate around a curve. The second, and the more problematic one for me, is that the buds generally don't stay in my ears. As a runner, with lots of jostling around, that's a problem for me.
When I explained my dilemma to Paul, he told me that he had a solution for me. First, he confirmed my ear irregularity, then told me to try the UE 700. Because of the earphone's foam outer shell, the buds did stay snugly in my ear. But what really got my attention, and why I wanted to take these earphones apart, was the amazing sound quality.
Paul explained to me why the tiny devices we able to produce such great sound. It comes from the fact that Ultimate Ears, which was acquired by Logitech in the Summer of 2008, has a reputation for producing professional-quality earphones. In fact, Paul told me a few tales about some of the musicians he had worked with. Funny stuff, but this likely isn't the place to tell those tales.
The UE 700 consists of dual speakers (also known as drivers) in a single package. In general, two types of miniature speakers are used for in-ear monitors. One is a diaphragm and one is an armature, which is what's used in the UE 700. The round diaphragm is typical of what you'd see in a home speaker.
The armature speaker originated from the hearing aid industry, and it's specifically designed to work inside of an ear in a closed compartment that doesn't need a lot of air. The diaphragms need more air to work properly. Usually the diaphragm product is rounder because of the shape of the diaphragm and there's often some kind of venting so air can get in and out. Hence, there's usually a hole or slot present. The diaphragm is generally used in lower cost products as it's a less expensive product to build.



