A member of the "Sirens Series" designed by Jerry Harvey of JH Audio in collaboration with Astell&Kern, the PSF11 Layla 12 Drivers Per Side Universal Fit In-Ear Monitors are inspired by the song "Layla" by Derek and the Dominos. The universal in-ear monitors use 12 drivers per side (4x low, 4x mid, 4x high) to deliver a frequency response of 10 to 23,000 Hz into a 20 ohm load with a sensitivity of 117 dB at 1 mW.
The drivers are connected by a three-way crossover network using 4th-order slopes and include Jerry Harvey's soundrIVe quad-driver technology, as well as his FreqPhase stainless steel tube waveguide technology to align the time and phase of the drivers. The earphones feature a full carbon fiber body with "burnt" titanium bezel and carbon fiber logo insert. The drivers were designed to be used as a mastering reference tool because the high driver was designed for optimum top end extension with minimal distortion. The mid driver section is designed to be flat from 10 to 5,000 Hz. The low driver section is designed to have a steep low pass with low distortion.
They utilize a 4-pin cable connection with a machined aluminum locking collar. Using the included screwdriver, the bass output of the cable can be boosted by as much as +13 dB at 60 Hz. An additional balanced output cable with a specific 2.5mm 4-pole terminal is included, which is intended for use with the Astell & Kern AK240 music player. A cleaning tool and a hard storage case are also included.