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ULTRA-Q PRO PEQ2200
Parametric equalizers can be used both as separate signal processors and in combination with conventional
graphic 1/3-oct. equalizers, for example, in a sound reinforcement system: while the 1/3-oct. equalizer does
the rough correction of the overall frequency response, the ULTRA-Q PRO could be used to fine-tune the
sound.
Notching out specific interference frequencies and narrow-band resonances (uncontrolled frequency peaks)
is one of the ULTRA-Q PROs major tasks: by tuning the EQ in to the precise trouble frequency, interference
such as hum and noise caused by air conditioners, etc. can be eliminated without affecting adjacent frequency
ranges. Basic acoustic problems usually encountered in studios and stage systems can be solved elegantly
with the ULTRA-Q PRO.
Owing to the special parallel filter configuration, the filter functions of the BEHRINGER ULTRA-Q PRO can be
combined to achieve a greater boost/cut of amplitudes than with one single filter. To do so, simply adjust two
filters to the same center frequency and bandwidth. With both LEVEL controls set to their left or right stop
position, the amount of amplitude cut or boost is doubled.
It has proven useful in practice to start with all controls set to mid-travel position and all IN/OUT switches OUT,
so as to avoid even before powering up the system that applied input signals with high amplitudes are raised in
level by the ULTRA-Q PRO and hence lead to distortion or damage in subsequent devices or speakers, or to
annoying feedback in PA systems caused by improper basic settings.
Once the filter curve of your choice has been set, it can be necessary to correct the overall level. If the filter
setting used raises the overall level, you can use the INPUT control to lower it again and avoid possible
distortion.
When the overall level is lowered by the filter setting, the INPUT control allows for raising it by a maximum
amount of +20 dB. Use the adjacent IN/OUT switch for a direct A/B comparison, so that you can estimate the
required amount of level compensation.
6.2 On phase shift and time delay
Any analog filter, be it graphic or parametric, produces a certain amount of phase shift.
Particularly in narrow-band filters this phase shift leads to specific delay of the audio signal: the narrower the
filter and the higher the gain, the greater the time delay. In certain applications, the effect on the sound image
can be annoying.
Although the ULTRA-Q PRO, owing to its unique concept, produces considerably less phase shift and hence
time delay than conventional parametric equalizers, this effect should nevertheless be taken into account.
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Please also note that filters show a natural tendency to produce a ringing sound as their
bandwidth is narrowed, an effect that is caused by system-intrinsic noise modulation that
occurs with any kind of filter. It is therefore recommended that you set all filters not in use to a
mid-travel position or simply switch them off to minimize these side effects as effectively as
possible.
6.3 Using a frequency analyzer
A frequency analyzer matching the ULTRA-Q PRO in that it provides the same narrow bandwidth (1/30 or 0.03
octaves) is a perfect tool to find optimum filter settings. If such a device is not available, a conventional 1/3-oct.
analyzer will do the job. For example, to reduce the risk of feedback in a sound reinforcement system, while
raising the overall level, you can use the 1/3-oct. frequency bands of the analyzer to identify the feedback
resonance frequency. Now, select the same frequency on the ULTRA-Q PRO using the FREQUENCY control,
set the BANDWIDTH control to its left stop position (minimum bandwidth) and cut the amplitude by 6-10 dB.
Switch on the filter and fine-tune the center frequency until feedback disappears. Then, raise the amplitude just
below the feedback-producing level. In this way, you can control the resonance frequency, while affecting
adjacent frequencies (and hence the overall sound image) to the least extent possible.
If you have a spectrum analyzer available with a resolution better than 1/12-octave, you can identify the
resonance frequency with much greater precision, which makes it easier to set up the ULTRA-Q PRO.
6. APPLICATIONS
