The DB1i uses a doped-paper 5.5? woofer and an oversized 27mm Sonolex soft dome tweeter. The crossover point is 2kHz. Perhaps the most interesting technical aspect of the DB1i is its Advanced Transmission Line (ATL) enclosure. The design incorporates a heavily-damped tunnel labyrinth that internally links the bass driver to a rear port. And according to PMC’s literature, the damping within the serpentine route absorbs frequencies from the upper bass on up while the lowest frequencies emerge in phase from the port. Compared to the more prosaic bass-reflex enclosure, transmission lines entail a complexity and expense that usually restricts them to larger, pricier efforts. Type: Two-way, transmission lineDrivers: 27mm tweeter, 5.5? mid/bassFrequency Response: 50Hz–25kHzSensitivity: 87dBImpedance: 8 ohmsDimensions: 11.4” x 6.1” x 9.2”Weight: 9.9 LbsOriginal Price: $950 each