The dbx 3BX Series Two Dynamic Range Expander was introduced in 1982 as the successor to the original dbx 3BX, providing improved performance and control in home and professional audio systems. It was designed to restore the dynamic range lost in the recording, broadcasting, or duplication process, giving playback a more natural, live quality.
By dividing the audio spectrum into three independent bands, high, mid, and low frequencies, the dbx 3BX Series Two was able to expand dynamics more transparently than single-band expanders, preventing unwanted tonal shifts when processing complex material. For example, a loud bass note would no longer cause mid and high frequencies to rise artificially.
The unit offered users up to 50% expansion, adjustable via simple slider controls, with the ability to set both the expansion amount and the transition level. A three-band LED display showed exactly how much expansion was taking place in each frequency range, making operation intuitive.
The inclusion of Pre and Post switching provided further flexibility: in Pre mode, the signal could be expanded before reaching the tape deck for recording, while in Post mode, expansion could be applied during playback. This made the dbx 3BX Series Two a versatile tool for enhancing tapes, records, and broadcasts, bringing them closer to the realism of live performance.
In addition to dynamics processing, the dbx 3BX Series Two also acted as a noise reducer, offering up to 20dB of source noise reduction, which was particularly useful for analogue tape recordings. This dual functionality made it especially attractive for hi-fi enthusiasts and semi-professional users looking to improve the fidelity of their systems.
The dbx 3BX Series Two was part of dbx’s broader push in the early 1980s to bring professional-level audio processing technology into the home, reflecting the company’s reputation for pioneering dynamic range control. Its blend of three-band expansion, user-friendly interface, and built-in noise reduction helped it stand out in an era when listeners were seeking higher fidelity from both records and the increasingly popular cassette tape format.
Features
- Three-band dynamic range expansion for transparent processing
- Up to 50% adjustable expansion with simple slider controls
- LED display showing expansion activity across all bands
- Pre/Post switching for flexible recording and playback use
- Noise reduction of up to 20dB
- Designed to enhance records, tapes, and broadcasts with live-like realism