TM
Quantum
QT 600 Manual
2.2 Punch
Pushing the PUNCH button activates a filter in front of the EQ
whose curve is shaped like that of a tube amp set up to deliver
clean sounds – the result is punchier and more lively sound.
The PUNCH filter's frequency response is tweaked to ensure
that there is no audible change in overall level.
2.3 Bass
Turning this knob up boosts frequencies ranging from 40 to 200 Hz
(with a centre frequency of 60 Hz), while scooping mids from 300
to 600 Hz. This emphasizes low-end frequencies. Turning the knob
down suppresses the low-end, raises the lower of the two limiting
frequency and boosts frequencies at 100 Hz. The overall energy of
the bass is maintained even when cutting frequencies.
2.4 Bass Shape
Turning on the BASS SHAPE knob activates a low cut filter at 80 Hz
with an edge steepness of 12dB in the bass band. Energy-consuming
sub-bass signals are filtered out, giving the amp and speaker more
room to breathe. Boosting to between 80 Hz and 160 Hz shifts a
portion of the energy one octave higher, which has a particularly
positive effect in problematic stage situations involving bass drums.
2.5 Low Mid
Turning this knob up boosts a broad range of frequencies neighbou-
ring the centre frequency of 400 Hz, adding presence and punch to
the bass signal. Turning this knob down filters out a narrow range
of frequencies around 400 Hz.
The figure shows the curve of the pre-filter
with the PUNCH button activated
The figure shows the BASS EQ's curve
when boosting (upper curve) and cutting
(lower curve) frequencies
The figure shows the filtering curve with
BASS SHAPE activated
The figure shows the LOW MID EQ's
curve when boosting (top curve) and
cutting (bottom curve) frequencies
2.6 Mid Boost
Activating the MID BOOST knob boosts a broad range of frequencies
around 220 Hz. This pre-filtering is excellent for classic soul sounds.
2.7 High Mid
As with LOW MID, frequencies are boosted in a broad band and
cut in a narrow band. The centre frequency is 800 Hz. This frequency
range is responsible for the "woody" quality of the signal-boosting
results in a pleasant, woody tone.
2.8 Treble
The TREBLE control has two functions. When the HF CHARACATER
button is deactivated, it works just like a classic level control,
producing a rather "metallic" sound. The character of the frequency
processing is emphasized by dampening frequencies lying above
the TREBLE control range's centre frequency.
When the HF CHARACTER button is activated, it works just like
a tube power amp's presence control, producing delicate, soft top-
end frequencies while simultaneously rolling off "harsher" sounding
frequencies found at the low end of the high frequency range.
Pushing the PUNCH button audibly enhances the effect of the
TREBLE control.
2.9 HF Character
Pushing the HF CHARACTER button activates a filter over the EQ
whose curve is similar to that of a "soft" tweeter. The effect is parti-
cularly prominent in the high-end response of basses with active
circuitry. With passive basses (or instruments whose strings are old)
this effect may barely be audible because there are few high-range
frequencies in the instrument's signal.
The figure shows the filtering curve with
MID-BOOST activated
The figure shows the HIGH MID EQ's
curve when boosting (top curve) and
cutting (bottom curve) frequencies
The figure shows the TREBLE-EQ's curve
when boosting (top curve) and cutting
(bottom curve) frequencies
The figure shows the pre-filter curve with
HF CHARACTER activated
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