Recommended Parts – Substitutions – Construction Hints
The parts and bi-wiring layout I have specified here for building my various 604 and 605 phase correct crossovers are ones I have used successfully with vintage Altec Lansing drivers in the past. The parts are not inexpensive, nor the layout … Continue reading →
Altec Lansing 604-8K Duplex Studio Monitor
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 →
Phase Correction for Altec Ferrite Duplexes
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 604-8H Crossover Revelations
Enter the H Model… In early 2004 I acquired a pair of 604-8Hs, the last ALNICO magnet duplex model Altec produced before they switched to ferrite magnets. It was also the first Altec duplex model that combined the Tangerine phase plug with a … Continue reading →
Phase Shift Between Drivers
I acquired a pair of 604Bs in the early 1990s, and had them refurbished with new 604E low frequency (LF) cones and new 16 ohm high frequency (HF) diaphragms at the Altec factory in Oklahoma City, Oklahoma. I subsequently used … Continue reading →
Altec-Lansing DUPLEX Speakers
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 →
The Altec-Lansing Model 19-MR3: The Loudspeaker That Never Was
The Altec-Lansing M500 Maestro is a largely lost and forgotten loudspeaker, but it is, perhaps, the best the company ever built. It arrived in the final days of Altec-Lansing, Inc., and production was cut short due to the sale of … Continue reading →