What made Castle unique among the burgeoning diversity of loudspeaker manufacturers in the ‘70s and ‘80s was their insistence on in-house design and manufacture of all the drive units and electronic components in their loudspeakers as well as the beautifully handcrafted real wood-veneered cabinets used to enclose them. The Castle brand rose to popularity through its introduction of models such as the famous ‘Howard’, ‘Harlech’, and ‘Durham’ and later adapted new technologies to introduce home cinema products, featuring the same attention to detail as the two channel models.