Congratulations @jaytor! Danny Richie is a master loudspeaker designer, and his products way over-perform their price points. Anyone wanting to learn how he engineers his designs can watch his GR Research Tech Talk Tuesday videos on You Tube. He REALLY knows what he is doing, and his speakers are extremely well designed. The thing is, good engineering doesn’t necessarily cost more than poor engineering, it just requires knowledge and wisdom, things you can’t put a price on. Watching his videos will make one a much more informed consumer.
I built the GR Research/Rythmik OB/Dipole Sub as well, which is easy enough for most anyone. I installed the dual-woofer version into a W-frame flat pack a fellow GR Research DIYer gave me for the price of shipping, but also bought the H-frame flat pack that is available from the guy in Canada making them for Danny. With it’s dadoes and alignment dowels, it’s no harder to build than an Ikea bookcase or dresser. He builds them out of 1.5" thick MDF, and in combination with the Rythmik A370 plate amp and 12" servo-feedback woofers, they make the best bass reproduction I have ever heard---the cleanest, most taut, and articulate. No bloat, no fat---pure muscle.