Welcome Ken,
Check out the GR Research page here on A.C.
I have built two of his state of the art models LS-9 and the Super V. Then bought several of the X series speakers on the used market after doing some research.
Danny is one of the best in the business when it comes to Loudspeaker design. Lots of fun to be had building with his kits and design help.
Best regards from San Diego,
Nick