HHB RADIUS40
Owner's Manual

HM Band
The HM (High-Mid Frequency) band is similar in operation to the LM band, except that the centre frequencies are obviously higher, and concentrated in the critical upper vocal region of the spectrum. The available frequency range is 1K5Hz to 5KHz.

more obvious complete switch off when the signal level drops. When the signal level returns to a level above the threshold, the gain is rapidly restored to ensure that no transient edges are lost. The gate can provide an effective creative tool by setting a relatively high threshold to produce a more defined fade out and switch back on, as well as being used conventionally to remove unwanted background noise. If the gate is not required in circuit, the threshold control should be set fully anti-clockwise (marked �Off�).

HF Band
The HF (High Frequency) band has a shelving characteristic, complimenting the LF band. Corner frequency selection is by rotary switch from 2K2Hz to 12KHz.

VU Meter
The processor is equipped with an illuminated VU meter. The meter should normally be used to monitor the audio output from the unit, and is calibrated for nominal level of +4dBu at the balanced output = 0VU. Similarly, 0dB on the meters also corresponds to -10dBu at the unbalanced output. However, should a very high output signal be required, for example +18dBu for a digital tape machine, the meter will be fully modulated and indicate full scale. This situation is catered for by the �Output +10� position on the meter selection switch, which attenuates the signal by 10dB before displaying it on the meter. Thus 10dB should be added to the meter reading in this mode, i.e., a meter reading of 0VU is equivalent to the normal level of +4dBu, plus 10dB, giving a signal level of +14dBu. The meter may be also be switched to indicate the input signal level (post the pre-amplifier but pre the EQ and compressor), or the amount of gain reduction (compression) applied by the compressor section. If the signal is below the threshold, the meter will read 0dB: i.e. no gain reduction is occurring. As the signal passes through the threshold the meter will show a negative value, indicating that gain reduction has started at the compressor stage. Note that the gain reduction indicated is a measure of the degree of compression, and does not include any gain make-up applied.

Bypass
The Equalizer In switch allows the processing to be bypassed for comparison of the equalised and original, unprocessed signal.

MASTER SECTION
The master level control is an output fader, which enables the voice processor output to be matched to the following equipment. The control is calibrated for 0dB at its centre, with a further 15dB of gain available by turning the knob fully clockwise. The additional gain may be useful if the output of the voice processor is connected directly to a digital recorder which requires a high level of modulation. Note that applying additional gain at the output will not increase the dynamic range of the signal, but will increase the noise level as well as the audio signal being recorded, and should therefore only be used if an output level in excess of the nominal +4dBu is required.

Gate
The gate circuit is located post the master level control, where it operates directly on the output signal. The gate operates by monitoring the signal level and expanding the level down by 24 to 30dB if the signal is below the threshold selected on the rotary control. This provides a natural sound, rather than a

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