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 1500Hz. The Altec supplied passive crossovers for most of these units were essentially the same as for the ALNICO 604-8H, namely third order high pass and second order low pass sections at 1500Hz with MF and HF EQ circuitry. Might there be a better circuit to phase correct ferrite motor Altec Duplexes than the 8H filter? A good question –......
Great Plains Audio was born out of the Altec Lansing corporation in 1998. It carries forward the loudspeaker design and manufacturing tradition that began with Western Electric in the early 20th century. Great Plains Audio is the only place where the legendary Western Electric/Altec Lansing sound reproduction technologies live on.
7127 Northwest Third St. Oklahoma City,
Oklahoma, USA, 73127