Sennheiser HD-414SL
The HD 414 SL is the updated reissue of Sennheiser's HD 414, the open supra-aural headphone that the company's own advertising counted as three million sold. Ads for the SL appeared in late 1984 - in Audio (December 1984, p.59) and HiFI-Stereo (December 1984, p.19) - and leaned heavily on the original's reputation. Sennheiser claimed the HD 414 had become standard equipment in recording and broadcast studios, a favorite of critics and music lovers, and was even used by NASA. The pitch was that Sennheiser had taken that model and made it better.
The clearest technical record is a Hirsch-Houck Laboratories test report in HiFI-Stereo (May 1985, p.32). The key change was electrical. The SL's impedance was cut to 600 ohms from the original's 2,000 ohms. The magazine noted this should make the phones more compatible with low-power signal sources such as compact portable players. The same test placed the SL among open supra-aural designs, which tend to give up a little bass next to circumaural headphones. It also observed that a relatively smooth measured frequency response generally corresponded with smooth subjective response.
Beyond these period sources, little is documented. No list price, production dates, or detailed driver specifications have surfaced. The SL appears to be a notable step in the HD 414 family's evolution, but the surviving archive on it is sparse.
Similar items on eBay
No exact Sennheiser HD-414 SL listings are live right now — these searches show current Sennheiser and similar vintage audio gear on eBay:
As an eBay Partner, we earn from qualifying purchases. This helps support our independent vintage technology research.
Related Models
- Sennheiser HD-222
- Sennheiser HD-224X
- Sennheiser HD-250
- Sennheiser HD-400
- Sennheiser HD-420
- Pioneer SE-305 (1982)
- Yamaha HP-3 (1978)
- Pioneer SE-21 (1979)
- Pioneer SE-4 (1975)
- AKG 240-DF