When you're trying to match a subwoofer to a very fast electrostatic panel, you can run into some real issues. Fortunately the engineers at Quad GMBH have been dealing with this issue for 50 years and have an excellent solution. First they realized that the sub would have to be a dipole to match radiating patterns and secondly it should have it's own amplification and DSP (digital room correction) to handle the low octaves without smearing perhaps the best mid-range in history. There are versions that can be built to hold a Quad Electrostat (serving as sub and stand) and also a round version (superb for adjusting in a room) that you see pictured of here. Finish of wood and cloth can be tailored to your desire.