Altec 604C
1954 - 1964
The Altec 604C is a step in the Duplex series between the early 604 models and the later 604E. It came out in the golden age of American hi-fi. Altec refined the coaxial design with better materials and manufacturing techniques, and kept the Alnico V magnet structure.
Specifications
| Type | 2-way coaxial loudspeaker (Duplex) |
|---|---|
| Low Frequency Driver | 15" cone with 3" voice coil |
| High Frequency Driver | 416-8A compression driver with 1.75" diaphragm |
| Horn | Sectoral multicellular horn (90° x 40°) |
| Crossover Frequency | 1,500 Hz |
| Nominal Impedance | 8 Ω or 16 Ω (604C-8, 604C-16) |
| Power Handling | 35W continuous |
| Sensitivity | 97 dB/W/m |
| Frequency Response | 30 Hz - 20 kHz |
| Magnet Structure | Alnico V |
| Weight | Approximately 42 lbs |
Design Evolution
The 604C made several improvements over earlier 604 models:
- Enhanced Voice Coil: 3-inch voice coil for improved power handling
- Refined Suspension: Updated surround materials for better linearity
- Improved Diaphragm: Tangential suspension for smoother HF response
- Better QC: Tighter manufacturing tolerances
The 604C in Studio Use
During the 1950s and early 1960s, the 604C was a fixture in professional recording studios. Its neutral, uncolored sound suited critical monitoring. Major recording facilities that used the 604C included:
- Capitol Records studios
- RCA Victor studios
- Columbia Records facilities
- Countless independent recording studios
Transition to the 604E
The 604E replaced the 604C in 1964. It brought an improved magnet structure and an updated crossover design. Many enthusiasts consider the 604C a sweet spot in the 604 lineup - modern enough to sound excellent, but still Alnico-era.
Key differences from the 604E:
- Slightly different high-frequency section tuning
- Earlier crossover topology
- Classic 1950s Altec manufacturing aesthetic
- Often preferred by vintage audio enthusiasts for its "classic" sound
Restoration Considerations
Today, the 604C has the same restoration problems as other vintage 604 models:
- Reconing: Available from specialized reconing services
- HF Diaphragms: Replacement diaphragms available for the 416-8A section
- Crossover Caps: Paper/oil capacitors should be replaced with modern equivalents
- Magnet Inspection: Alnico magnets should be checked for demagnetization
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Historical Significance
The 604C represents an important transitional model in the 604 series. It maintained the classic Altec sound while incorporating improvements that would lead to the highly regarded 604E. For collectors and vintage audio enthusiasts, the 604C offers a glimpse into the 604's evolution during the golden age of American audio manufacturing.
Documentation
- Altec Datasheets - Technical specifications
- Lansing Heritage - Historical information
Related Models
- Altec 1803B
- Altec 23746 (1975)
- Altec 26421 (1975)
- Altec 288-16G
- Altec 288-8H/16H
- Braun AUDIO-1 (1965)
- Braun AUDIO-250 (1965)
- Magnavox Component Systems (1972)
- Acoustic Research AR (1967-1976)
- Acoustic Research 11