Capacitive Coupling Technology

The key to rich bass from the OWM3

The OWM3 is an ultra-compact satellite/surround loudspeaker by design. This compactness and curved shape make the OWM3 extraordinarily versatile when it comes to placement, offering no fewer than seven options. But the OWM3’s compact design necessarily means that its internal enclosure volume is quite small which would normally have undesirable implications on its bass performance. But the accepted tradeoff made by conventional loudspeakers and their designers, whereby small enclosure volume comes only at the expense of both low-frequency extension and acoustic sensitivity, was challenged by Polk Audio. Capacitive Coupling Technology, an established technique for extending the bass response of small, sealed-box loudspeaker systems, has been exploited by Polk to meet the demands of a market hungry for versatile applications oriented loudspeakers of uncompromised audio performance.

In the graph below, the dotted line traces reflect the OWM3’s performance characteristics in the absence of capacitive coupling, while the solid green and magenta traces indicate how CCT effectively improves low-frequency extension by nearly one-quarter of an octave, yielding 3dB more acoustic output over the lowest octave of its passband.

Properly employed, CCT works by creating a benign impedance dip within the range where conventional sealed-box loudspeakers are subject to severely reduced bass output. Lower impedance – but not too low for consumer power amplifiers and receivers with which the OWM3 will be paired -- within this critical frequency range means improved acoustic sensitivity by exploiting power amplifiers’ ability to deliver more current into such loads. Thus, properly designed CCT loudspeakers, such as the OWM3, play surprisingly loud over the lowest portion of their passband. The net result for the OWM3’s performance is 3dB more bass output over a fairly broad range. It’s as if the loudspeaker’s enclosure grew by 30 to 40% in volume. And it’s why you’ll be astonished by just how loud and how low a satellite/surround loudspeaker this compact goes.