appropriate frequencies, thus changing the spectral content of the original signal. The STEREO VITALIZER , however, relies on a more subtle method of amplitude-depending phase shifting. This does not involve altering the spectral composition of the signal but it does maintain the subjective impression of loudness. Moreover, graphic equalizers produce comb-filter effects because of the interaction between adjacent filters, when broad- band frequencies are raised. The MID-HITUNE filter can raise the broad- band spectrum with a very linear frequency response, without colouring the signal.
Above the MID-HITUNE value set, the STEREO VITALIZER filters create a linear increase, i.e. one that is adapted to the human ear. This compensates any inability of our hearing as regards perceiving frequencies ranging between 5 kHz and 10 kHz. The MID-HITUNE filter works with a wide bandwidth and always sounds musical, never »bell-like«. Gradually go down from 20 kHz (extreme left) to lower frequencies. The further down you go, the brighter the sound image becomes, as an increasing number of frequencies are included in the process.
The MID-HITUNE control can also be used to tone down excessively sharp-sounding material, by setting frequencies of 10 kHz or higher, and setting the PROCESS control on MAX. Seeing as the PROCESS control is also responsible for deleting dominant mid frequencies, all frequencies are gradually reduced down to the application frequency, in conjunction with high starting frequencies of the MID-HITUNE control.