My buddy has a pair in the basement. He was using them up until the foam surrounds on the woofers rotted. The highs are nice and airy but do not integrate well with the woofers and the mids collapse and sound very dark and recessed. They are difficult to drive also. Typical 70's heavy woofer syndrome. Underdamped like Cerwin-Vega's. They are not cheap to rebuild and there are better alternatives to the Heil Transformer.