Altec 604C
1954 - 1964
The Altec 604C represented a significant evolution in the Duplex series, bridging the gap between the early 604 models and the later 604E. Produced during the golden age of American hi-fi, the 604C refined the coaxial concept with improved materials and manufacturing techniques while maintaining the classic 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 incorporated 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 became a fixture in professional recording studios. Its neutral, uncolored sound made it ideal for critical monitoring applications. 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The 604C was eventually superseded by the 604E in 1964. The 604E brought further refinements including an improved magnet structure and updated crossover design. However, many enthusiasts consider the 604C to represent a sweet spot in the 604 lineage—modern enough to sound excellent, yet retaining the classic Alnico-era character.
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 presents similar restoration challenges to 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 1221A
- Altec 3000B
- Altec 600B
- Altec 603
- Altec A4X
- Akai AM-2850 (1975)
- Akai AP-206 (1975)
- Nakamichi BX-1 (1985)
- Acoustic Research research-ar-17 (1978)
- Acoustic Research AR-19 (1994)