Like the rest of the range, and despite its smaller size, the 686 S2 also features a Decoupled Double Dome aluminium tweeter for superior high-frequency response. The 686 S2 even features a built-in bracket for easy wall mounting, although this small, versatile and precise speaker sounds great anywhere. An ideal bookshelf or wall-mounted speaker, the 686 S2 is designed to fit into any space and still sound perfect. Its main driver is a 5-inch bass/midrange unit which benefits from a new 25mm voice coil which makes for a higher sensitivity speaker with bass more suited for placement near a wall.Bass performance is vital but can often suffer in smaller speakers. Not in the 686 S2, however. That's because a front-firing Flowport, dimpled like a golf ball around the aperture for smoothly regulated airflow, delivers superior bass response without the risk of rattle. Its placement ensures the speaker cabinet is slimmer than predecessors and can be wall mounted without affecting performance Woven Kevlar  YES Crossover Tuning  YES Nautilus Tapering Tube  YES Flowport  YES Technical features Decoupled Double Dome aluminium tweeter with Nautilus™ tube loadingFlowport™ Description 2-way vented-box system Drive units 1x ø25mm (1 in) aluminium dome high-frequency1x ø130mm (5 in) woven Kevlar® cone bass/midrange Frequency range -6dB at 54Hz and 50kHz Frequency response 62Hz - 22kHz ±3dB on reference axis Dispersion Within 2dB of reference responseHorizontal: over 60º arcVertical: over 10º arc Sensitivity (84)85dB spl (2.83V, 1m) Harmonic distortion 2nd and 3rd harmonics (90dB, 1m)