Audiovox PEQ-200 User Manual download pdf (Page 14)

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 PROs 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.

+ 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

1 2 ... 9 10 11 12 13 14 15 16 17 18 19 20 21

Comments to this Manuals

No comments

Audiovox PEQ-200 User Manual Page 14

Comments to this Manuals