This pair of 4" bookshelf 2-way vented speakers have a 4" high-excursion driver with a treated paper cone which extends the low-frequency range to play down to a 60Hz range and uses a 3/4" silk dome tweeter. This pair of speakers have a built-in amplifier, able to produce up to 80W maximum of detailed sound. The powered speaker has both Bluetooth 4.2 and 3.5mm inputs, as well as control of volume, tracks and pause/play from the top of the speaker. The built-in crossover features a 3.3 kHz, 1st order high-pass, 2nd order low-pass filter. The 7-component crossover uses asymmetrical slopes to help blend the two drivers with a flatter treble response that delivers a smoother high-end. These speakers have a removable grill and fully-sealed wooden cabinet finished in a textured black vinyl that minimizes resonance and enhances warmth without sacrificing clarity. Dimensions are 9.5" H x 5.75" W x 6.6" D.