The Great Plains Audio 604-8H III Rev. 2 is more than just an evolution in the classic series of 604 Duplexes, it’s an AUDIO REVELATION! For more than fifty years, there has been one studio monitor loudspeaker that has been … Continue reading →
In early 2008 I had the opportunity to evaluate a loaned Altec Lansing 604-8K utilizing the CLIO system. The driver was an early unit (serial # 3403, date stamped DEC 1982) and was equipped with the original factory low frequency cone and … Continue reading →
Ferrite Magnet 604s As I mentioned on the Home Page, horizontal separation between voice coil gaps for ferrite magnet Altec Lansing 604 & 904 duplexes is 2.8125”. This distance produces 112 degrees of phase shift between the driver’s acoustic centers at … Continue reading →
Altec Lansing invented the first DUPLEX® Loudspeaker System in 1941 (some sources say 1943 – we’re really not sure). Called the “601”, it was of the field-coil type and included a small-format HF compression driver mounted to a 12″ low … Continue reading →
