JBL ES20 Bookshelf Speaker Pair

The ES20 speaker’s fit and finish are remarkable for the price. I discovered this when I pried off the grille, a three-piece construction in black with decorative top and bottom stripes in gray. The six plastic pins held so snugly in their rubber holes that I had to carefully unseat them one at a time—and it took all the strength in my fingers. The back of the ES20 features gold-plated binding posts with a knurled surface that’s easy to grab. The posts plug in the back, as most products conforming to CE safety rules do these days. However, I could insert my banana-plug speaker cable into holes in the sides of the posts.

Despite its modest 12.5-inch stature, the ES20 is a three-way speaker with a 5-inch woofer. The woofer is made of PolyPlas, or polymer-coated cellulose. Instead of a midrange and tweeter, the speaker contains a tweeter and super-tweeter. In JBL-speak, these are called “high-frequency” and “ultrahigh-frequency transducers.” The tweeter is a 0.75-inch version of JBL’s familiar titanium-laminate dome, in a shallow waveguide. It crosses over from the woofer at 3,300 hertz. The super-tweeter at top is a 0.75-inch polyester-film ring radiator, in a deeper waveguide, with a phase plug in the center. According to JBL, it crosses over from the tweeter at 12 kilohertz and extends out to 40 kHz.