DESC: Yamaha's NS-555 speaker system has been designed specifically for home theater applications. The floor standing speaker is a bass-reflex design that can be used for main channels and incorporates a pair of 6 1/4" Polymer-Injected Mica Diaphragm (PMD) cone woofers, a 5" midrange cone driver and a 1" aluminum dome tweeter. For improved imaging, the midrange and tweeter utilize Yamaha's exclusive waveguide horns.