App: DxII Codec — for dbx-II/Disc
Developer: Chen Wang
Genres: Entertainment, Utilities

DxII Codec is a precise digital emulation of the analog dbx-II/Disc noise reduction system for audio tape/LP. The software app is capable of decoding/encoding dbx-II/Disc formatted audio in digital domain. Powered by the proprietary DSP engine, the decoding/encoding can be performed in realtime, which allows for instant processing, monitoring and fine-tuning.

Deeper optimal result can be achieved by using the fine-tuning tools that come with the software, as specified below:

- Dual-meter: visualizes potential risks of dynamic-range overload or underload, with adjustable means for instant correction.

- Play Trim: compensates for signal degradation with aged pre-recorded tapes.

- Azimuth Correction: a limited-effect tool for remedying slight phase displacement and high-frequency loss caused by the azimuth error of the playback head.

- Gap-Loss Compensation: a limited-effect tool for counteracting slight playback head wear.

- EQ Converter: a utility for converting between IEC 120μs and 70μs EQ schemes, offering flexibility when the tape player/recorder lacks this option.

- RMS timing slider: offers optional flexibility to adjust the compander's tracking speed.

- Ref. Tone Generator: offers 400Hz 0dB signal at Dolby Reference Level for easy calibration.

Each of these tools can operate independently of the NR codec, which can be used for refining the audio digitized from analog audio tapes, regardless of whether NR is involved.

DxII Codec is a stand-alone GUI app without relying on any other DAW host. It allows the computer to serve as an external(outboard) dbx-II/Disc unit in one of the following four modes:

- from Audio-In to File (a digitizer/recorder).
- from File to Audio-Out (a player).
- from File to File (an off-line processor, with batch capability).
- from Audio-In to Audio-Out (a through processor, with slight delay).

Currently supported audio file formats are:
WAV, FLAC, AIFF: up to 96k/24bit.
MP3, AAC,  M4A:  up to 48k/VBRS.
* Excluding some proprietary variants having the common file extensions, or additional format-normalization may be required.

A VST plugin is also available as an optional software component of the application.

The software comes with embedded user manual on each major functions.

Please note that this software is suited for the consumer grade dbx type-II or type-Disc, which is not compatible with the professional grade dbx type-I.

Release notes:
- New recording is now unprocessed.
- Introduced anti-clipping feature by file saving.
- Updated embedded document.