Turbosound TQ-440 - Manual (Page 7)

user manual
QLight    series
TQ-440 manual
page 7
Equalisation
Because the TQ-440 features a smooth and even frequency response, it does not need equalisation
or correction to overcome the deficiencies often found in lesser designs.
Should extended frequency response be required at more than medium sound pressure levels, the
use of the complementary TQ-425 subwoofer is strongly recommended.
In order to to compensate for the room acoustics, the TQ-440 requires only minimal equalisation.
As in any system, over-equalisation introduces phase shifts, distortion and a reduction in
headroom, usually causing more problems than it cures.
Under most circumstances a 1/3 or 1/2 octave graphic equaliser will generally be adequate, with
the fader settings applied smoothly and as little as possible for the required room compensation.
Most rooms will have resonances that will be excited at particular frequencies needing some
cut to
help tame the sound, these problems are most pronounced at the lower frequencies where
speakers generally exhibit very little directional control.
If you find that the system needs a lot of boost at lower frequencies you may need additional sub-
bass units. It is good practice to use as little equalisation as possible, aiming to cut frequencies
rather than adding large amounts of boost.
Dispersion
One of the design features of the TQ-440 is its tightly controlled 60º horizontal by 40º vertical
nominal dispersion pattern at mid and high frequencies. This gives many user advantages and
eases placement decisions, being essentially a point and shoot system. A 60º horizontal polar
pattern equals an angle of 30º either side of the centre line at which the sound pressure level is 6
dB down with respect to centre, (averaged over the whole frequency range of the loudspeaker).
Thus a 40º vertical dispersion gives an angle of 20º above and below the horizon.