Technical White Papers

PSW650 Powered Subwoofer Press Brief

The goal of the PSW650 project was to design a subwoofer that was equally adept for music and home theater applications that sold for a price within the reach of most home theater consumers ($780 MSRP).

On the back of the enclosure there are two Power Ports—plates with a molded-in cone that points into the mouth of the port hole.

The Power Port is a compact, efficient patented port system capable of handling the tremendous volumes of air-flow required for deep bass reproduction with very low turbulence, noise and loss. It solves the fundamental problem of conventional port systems—air turbulence. Air from inside the cabinet moves through the small port at very high velocity. When it exits the port into the room, the abrupt transition from the small diameter port to the room creates turbulence at the mouth of the port. In its worst form, this turbulence creates audible "port noise", heard as a "chuffing" sound. Also, up to 2dB of bass is lost because of the turbulence. To reduce this turbulence, the Power Port consists of a "cone" at the mouth of the port and the space in between the enclosure and the plate. The cone promotes laminar airflow and the ever-increasing cross-sectional area of the space mimics a very long flared port.

In the PSW650, the dual Power Ports extend deep bass response and lower low frequency distortion.

The driver-side baffles are one inch thick MDF and the remaining four panels are ¾" MDF. Internal bracing further serves to reduce panel resonance.

The PSW650 uses two 10 inch woofer drivers that provide 39% greater surface area than a single 12 inch driver. The subwoofer delivers the air-moving ability of a single large driver for gut-wrenching home theater bass and the speed, rhythm and pace of small drivers for accurate music performance.

The subwoofer offers both speaker level and line level 80 Hz high pass filters. This feature is useful for systems that have no bass management functions (such as stereo and ProLogic gear).

The LFE/Subwoofer In jack bypasses the sub’s adjustable low-pass crossover for use with processor’s whose sub out jack is already filtered. Doubling up low pass filters can result in loss of sat-to-sub blending control and reduced performance.

The subwoofer volume control is on the front of the sub, under the Polk logo "pod." Subwoofer level adjustments can be made without crawling behind the sub. In honor of Spinal Tap (our favorite Rock ‘n Roll band), the volume control goes up to 11.

The preamp section of the subwoofer uses differential inputs which allow the simultaneous use of mixed (line and speaker level) inputs. This allows a wide variety of hook up options to get the best possible performance from a given system.

The speaker wire terminals are gold-plated 5-way binding posts. Note that the wire holes in the screw shafts are large enough to accommodate tinned 12 gauge wire. The PSW650 can be connected with high grade speaker wire without the need for accessory pins, plugs or lugs. (although all can be used). The PSW650 offers secure, reliable and high performance wire termination.