These are sold ONLY in pairs. This price is for (2) speakers. The Control 128W is a premium in-wall speaker within the JBL Professional Control(r) Contractor line designed for applications such as foreground music, boardrooms, reception areas, airports, convention centers, cruise ships, retail outlets, restaurants, museums, surround locations, or any critical listening application where top performance from a loudspeaker with minimal visual impact is required.The high-performance woofer features a polymer-coated aluminum cone for high performance down to 30 Hz and pure butyl rubber surround for long-life and high reliability along with extended-pole piece magnet design for long excursion and tight, low bass. The pure titanium dome high frequency driver is loaded with a built-in EOS(tm) (Elliptical Oblate Spheroidal) waveguide for low distortion and a smooth frequency response. A low-diffraction swivel mounting system enables the user to direct high frequencies where required without the diffraction distortion inherent in other aimable tweeter designs. A high-slope crossover network maintains natural midrange sound and produces more even coverage throughout the listening area. The optional Control 128WT version includes a multitap transformer for 70V/100V systems. The Control 100 Series speakers are voiced similarly to other JBL Control Contractor models, allowing mixing with surface-mount and in-ceiling speakers within a single listening space. The premium sound quality makes these loudspeakers ideal for critical listening environments, yet they are high power and rugged enough to handle venues requiring high-SPL, heavy duty-cycle music.The speaker fits into the wall space of ordinary stud-wall construction. An optional rough-in frame is available for installing the speakers into standard stud walls in new construction projects. As is the case with all Control Contractor speakers, the baffles and grilles are paintable to match any decor.
Rear Air Cavity Considerations The Control 128W is designed to function over a wide span of rear air cavity sizes within the wall. The optimum air cavity (sometimes called "loading volume") for fullest low frequency performance is between 40 to 80 liters (1.4 to 2.8 cu ft). In a wall with studs located 16-inches on-center, this approximately equals a 46-inch to 92-inch high space. It is recommended that the air cavity behind the speaker be sealed by the use of silicone sealant or similar material to help create an air-tight seal and minimize wall noise.