Slow-speed recording (e.g., cassette) has a poor overload level at high frequencies relative to middle frequencies. The recording bias current and equalization are compromises between high frequency saturation and other aspects of performance (distortion, drop-outs, modulation noise, etc.). This paper describes a system, called headroom extension, which continuously adapts the recording bias and equalization to suit the high frequency spectrum of the input signal, as determined by the control circuitry of the Dolby B-Type noise reduction processor. An optimum type of controlled equalization for this purpose is presented. Application of the headroom extension system to cassette recording results in a high frequency signal handling capability improvement on the order of 10 dB above 10 kHz.
Click to purchase paper as a non-member or login as an AES member. If your company or school subscribes to the E-Library then switch to the institutional version. If you are not an AES member and would like to subscribe to the E-Library then Join the AES!
This paper costs $33 for non-members and is free for AES members and E-Library subscribers.