DJ (the owner of AQ) is the father of Jassa (owner of DD).... The HDC3 is assembled in China, the aluminum coils are assembled at DD. All AQ products are warehoused and packaged at DD and shipped from DD. All warranty work is done at DD. The difference between an AQ HDC3 and a DD 9500 is the AQ is built in China and it does not have as many options as the DD and it does not have as much cooling as the 9500. Same size coil (AQ uses a Chinese coil except the aluminum is US and DD uses a US coil), same size magnets, same size top plate (DD has cooling channels in the top plate and down the T-Yoke and it is crossed drilled through the t-yoke) The AQ only has a vented t-yoke and the top of the t-yoke is cupped for better cooling. As a result of the extra cooling in the motor, the DD 9500 will handle more power than the AQ with the copper voice coil BUT, they are pretty close with the aluminum coil. (Basically you are paying dealer price on the AQ if it was not dealer direct only).......