Velodyne DD 10 PLUS with built-in crossover & equalizer

This is a beautiful ebony subwoofer.  It puts out excellent bass, whether it is for music and a home theater.  The built in equalizer and microphone enables you to use the included CD generated tome to set up your system for appropriate bass response with this unit.  The crossover can be used balanced or single-ended to fine tune your setup.  It provides fast, tight bass response with excellent transients.  No fees for Paypal.
From the Velodyne website: 

The Digital DrivePLUS (DD-10+) subwoofer produces awe-inspiring, hard-hitting bass backed by cutting-edge technology to whittle distortion down to less than ½ %. The DD-10+ perfectly meshes audio engineering with the art of design to deliver a frequency response between 18.7 and 120 Hz at 3dB down with a huge 3000 Watt dynamic amplifier, reproducing even the most challenging audio for applications from music to home theater to gaming. The DD-10+ deftly fills medium-sized rooms (2000-3500 cu. ft.) with incredibly accurate bass, perfectly optimized by the 8-band Auto-EQPLUS feature and remote-controlled presets to ensure you get the most out of your new audio equipment.

If you refuse to compromise on performance and want to electrify your audio media in a medium-sized listening space, the DD-10+ is for you.

Features

One-Touch Auto-EQPLUS automates the seamless blend of subwoofer, system and room

Use your PC for manual adjustments and real time feedback of your bass performance

The industry's lowest distortion bass—under .5%

Sophisticated cone design for fast, accurate motion

Six-layer, custom wound voice coil assures better heat dissipation

Massive motor structure for amazing low-frequency energy