Gradient 63 subwoofer system [Expired]

Gradient 63 subwoofer system designed for Quad 63 speakers.  There are two units that act as custom bases for Quad 63 speakers and one electronic box that is an XLR crossover.  These were designed to provide a improved bass response for the 63's and do not effect the beautiful Quad midrange.  You can look these up as there is much written about them.  Both units have replacement bass speakers that are in excellent condition.  These moved the Quads into the full range speaker world.  The reason for the sale is that I purchased a REL G1.  I will answer any questions that I can.