SoundTube - IPD-SM500i-II - 5.25" Surface Mount Speaker (Single) The IPD-SM500i-II is a 5.25-inch, two-way surface-mount speaker with a midsize enclosure design that delivers effective low-end response (60 Hz) and optimal off-axis performance (2 to 10 kHz). SoundTube’s proprietary BroadBeam waveguide tweeter system delivers consistent high-performance audio across operating bandwidth. The IPD-SM500i-II speaker design incorporates a low-profile grille, six-position tap switch with transformer bypass and mounting hardware, including the Stealth bracket mounting system. The IP-SM500i-II incorporates a security knob to reduce tampering after placement, unlimited directional aiming, and low profile.