Parametric Equalizer (Front Panel; #6)
A parametric equalizer offers continuous and independent control over
the audio signal’s frequency content, which is divided into five frequency
bands on the Platinum Series amplifiers. These controls are:
In equalizers, Q is the ratio of center frequency to bandwidth, and if the
center frequency is fixed, then bandwidth is inversely proportional to Q—
meaning that as you raise the Q, you narrow the bandwidth. For example,
if the 1kHz filter is set to 1kHz, the Q will vary from (1618-618)/1000 =
1000/1000 = 1 minimum Q, or maximum bandwidth of 1000 Hz, to
1000/(1051-951) = 1000/100 = 10 maximum Q, or minimum bandwidth
of 100 Hz.
Q is the most useful tool a parametric EQ offers, allowing you to boost/cut
(with the GAIN control for that frequency band) a very narrow or wide
range of frequencies within each EQ band.
A narrow bandwidth (high Q value) is particularly useful for removing
unpleasant tones. By notching out the offending frequency, you can
remove the problem without removing adjacent frequency content.
A broad bandwidth (low Q value) boosts/cuts (with the GAIN control for
that frequency band) a larger band of frequencies. Broad and narrow
bandwidths (low and high Q, respectively) are usually used in conjunction
with one another to achieve the desired sonic effect.
• GAIN - The gain (boost/cut) for each frequency band. The gain range
for the Platinum Series is -15 dB to ±15 dB as indicated on the GAIN
row of controls on the Platinum Series front panel.
• FREQ (Frequency) - The frequency region where the gain boost/
cut is desired. The five filter frequency ranges are indicated in the
FREQ row of controls on the Platinum Series front panel. Each
frequency band is approximately two octaves wide and is constrained
within the five control columns on the Platinum Series front panel.
• Q - This is a form of “frequency bandwidth” control centered about the
frequency region where the gain boost/cut is desired. Its value is
calculated as the ratio of the center frequency to the bandwidth. The
filter Q setting is indicated in the Q row of controls on the Platinum
Series front panel.
Variable Mute (Rear Panel; #6)
The VAR MUTE control mutes the AUX input(s) only during telephone
pages. The control allows the user to select from 4 levels of muting:
1 = -60 dB, 2 = -21 dB, 3 = -10 dB, 4 = 0 dB.
Telephone Paging Controls & Settings
(Front Panel; #3)
The MIC 5/TEL volume control on the front panel controls the volume of
the telephone paging input when the control is set to the TEL mode (See
page 4 for information on setting the TEL input mode).
The TEL input mode uses voice-activated muting for the AUX inputs and
automatic level control for providing constant paging level. To optimize
TEL input performance, both the ALC control and the VOX threshold may
need to be adjusted.