I'm not sure what you mean by 'adjustable?' I own the Pendragons, and they have plenty of bass down to the mid 20's. There are no separate controls for adjusting the bass on the speakers, if that is what you mean. I have a very nice sub, but I only use it for HT with the Pendragons.
pendragon base
Does anyone know if the base on the Tekton Pendragon is adjustable? Based on the incredible reviews the base might be enough to enjoy without a sub.......for now.