User manual BEHRINGER PEQ2200

[. . . ] PEQ2200 Users Manual Version 1. 2 September 2001 ULTRA-Q PRO ® www. behringer. com ENGLISH ULTRA-Q PRO PEQ2200 SAFETY INSTRUCTIONS CAUTION: To reduce the risk of electric shock, do not remove the cover (or back). No user serviceable parts inside; refer servicing to qualified personnel. WARNING: To reduce the risk of fire or electric shock, do not expose this appliance to rain or moisture. This symbol, wherever it appears, alerts you to the presence of uninsulated dangerous voltage inside the enclosurevoltage that may be sufficient to constitute a risk of shock. This symbol, wherever it appears, alerts you to important operating and maintenance instructions in the accompanying literature. [. . . ] TECHNICAL BACKGROUND 5. 1 Introduction The ULTRA-Q PRO combines the technical properties of both parametric equalizers and narrow-band notch filters. Owing to its variable bandwidth ranging from 0. 03 to 2 octaves, it is much more flexible than conventional EQs. Its innovative circuit topology gives you the appropriate tools to solve acoustic problems of any kind. The ULTRA-Q PRO also has two additional filters which enable you to adapt the entire frequency response to meet your specific application. Practice has shown how important this feature is, as most acoustic problems are encountered in the extreme low and high frequency ranges. Typical frequency response, hum or feedback problems must be handled differently. The additional low and high-cut filters allow for a broad-band correction of the frequency curve, while the parametric filters can be used to process narrow frequency bands (mains hum, feedback, etc. ). Turn the BANDWIDTH control counter-clockwise to adjust the minimum quality of 0. 03 octaves, and clockwise to adjust the maximum bandwidth. Turn the LEVEL control clockwise to raise, or counter-clockwise to lower the filter amplitude. 5. 1: Various filter qualities During operation you can switch on and off the individual bands to make an A/B comparison between the equalizer effect and the unprocessed signal. Due to the complex and partly difficult settings of parametric equalizers such a facility is indispensable. Still, most parametric EQs have no band-specific in/out switches which makes it difficult to keep track of what the various switches and controls do. 5. 2 The Constant-Q principle One of the most important features any graphic or parametric equalizer has to offer is the independent control of its various parameters. The special state-variable filters of the ULTRA-Q PROs use the so-called Constant Q principle which prevents the parameters frequency, bandwidth and amplitude from influencing each other. In the same way, the mutual influence of the individual frequency bands is avoided, which is a fundamental requirement as it allows for clearly defined and repeatable filter settings. When several filters are used simultaneously, the resulting overall filter curve can be calculated by adding/subtracting the single band-specific filter curves. 5. 3 The concept of parallel filters Unlike conventional parametric equalizers the ULTRA-Q PRO features a parallel filter configuration, which offers a decisive advantage over series-type configurations: with parallel filters it is possible to reduce to a minimum the phase shifts and delays usually associated with filters, which is the reason why the ULTRA-Q PRO is such a musical device. Naturally, this concept, too, is subject to a few limitations: unlike series-type filter configurations the concept of parallel filters allows only to a limited extent for an extreme boost/cut of frequencies. However, as extreme settings are usually the result of an improperly adjusted sound image, it is imperative that deficiencies of this kind be identified and eliminated, before the actual musical fine-tuning of the sound image takes place. Still, extreme settings can be realized by overlapping the frequencies of the individual bands. 5. 4 Filter functions 5. 4. 1 The notch function With notching or peaking we describe the specific attenuation of single frequencies or frequency bands. A notch filter produces an effect that is the opposite to a band-pass filter. 12 5. 5. 2: Typical notch function 5. 4. 2 The roll-off function With roll-off we usually refer to a limitation of frequency bands by means of high or low-pass filters. The low and high-cut filters on the ULTRA-Q PRO have a slope of 12 dB/oct. APPLICATIONS 6. 1 Introduction and basic settings In contrast to graphic equalizers with their fixed frequencies and qualities, parametric EQs allow for setting all filter parameters, such as center frequency, bandwidth and amplitude. [. . . ] Warranty services will be furnished only if the product is accompanied by a copy of the original retail dealers invoice. Any product deemed eligible for repair or replacement by BEHRINGER under the terms of this warranty will be repaired or replaced within 30 days of receipt of the product at BEHRINGER. If the product needs to be modified or adapted in order to comply with applicable technical or safety standards on a national or local level, in any country which is not the country for which the product was originally developed and manufactured, this modification/adaptation shall not be considered a defect in materials or workmanship. The warranty does not cover any such modification/adaptation, irrespective of whether it was carried out properly or not. [. . . ]