Behringer DEQ2496 User Manual

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ULTRACURVE PRO DEQ2496

User’s Manual

Version 1.1 July 2003

ENGLISH

ULTRACURVE PRO DEQ2496

IMPORTANT SAFETY INSTRUCTIONS

CAUTION: To reduce the risk of electric shock, do not remove the top cover (or the rear section). 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 and moisture.

This symbol, wherever it appears, alerts you to the presence of uninsulated dangerous voltage inside the enclosure—voltagethat 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. Please read the manual.

DETAILED SAFETY INSTRUCTIONS:

1)Read these instructions.

2)Keep these instructions.

3)Heed all warnings.

4)Follow all instructions.

5)Do not use this device near water.

6)Clean only with a dry cloth.

7)Do not block any ventilation openings. Install in accordance with the manufacturer’s instructions.

8)Do not install near any heat sources such as radiators, heat registers, stoves, or other apparatus (including amplifiers) that produce heat.

9)Do not defeat the safety purpose of the polarized or grounding-typeplug. A polarized plug has two blades with one wider than the other. A grounding type plug has two blades and a third grounding prong. The wide blade or the third prong are provided for your safety. If the provided plug does not fit into your outlet, consult an electrician for replacement of the obsolete outlet.

10)Protect the power cord from being walked on or pinched particularly at plugs, extension cords, and the point at which they exit the unit.

11)Only use attachments/accessories specified by the manufacturer.

12)Use only with the cart, stand, tripod, bracket, or table specified by the manufacturer, or sold with the device. When a cart is used, use caution when moving the cart/ device combination to avoid injury from stumbling over it.

13)Unplug this device during lightning storms or when not used for long periods of time.

14)Refer all servicing to qualified service personnel. Servicing is required when the unit has been damaged in any way, such as power supply cord or plug is damaged, liquid has been spilled or objects have fallen into the device, the unit has been exposed to rain or moisture, does not operate normally, or has been dropped.

2

ULTRACURVE PRO DEQ2496

MENU STRUCTURE

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

MENU STRUCTURE

3

ULTRACURVE PRO DEQ2496

ULTRACURVE PRO

Ultra high-precisiondigital24-bit/96kHz EQ/RTA mastering processor

sUltra high-resolutionprocessor for all EQ, RTA and dynamic applications, especially forDEQ2496PA and audiophile mastering

s4 concurrently selectable EQ modules (31-bandgraphic EQ,10-bandparametric EQ, Feedback Destroyer plus three Dynamic EQs per stereo channel)

sFlexible Compressor/Expander function with Peak Limiter per stereo channel as well as additional Stereo Imager and Stereo Delay for delay line applications

sUnique VPQ (Virtual Paragraphic EQ) option allows parametric control of graphic EQs

sUltra high-resolution61-bandreal-timeFFT Analyzer with additional auto EQ function for room and loudspeaker equalization

sMulti-functionallevel meters (peak/RMS, VU and SPL meter with dBA/dBC weighting via RTA mic input)

s64 user memories for complete setups and/or individual module configurations

sSeparate RTA mic/line input with phantom power, professional wordclock input and MIDI connections for full remote control, preset dumps and system updates

sUltra high-qualityAKM® 24-bit/96kHz A/D- and D/A converters (113 dB dynamic range)

sOpen architecture allowing future software updates via MIDI

sTwo high-performance32/40-bitfloating-pointSHARC® digital signal processors for ultimate sonic resolution

sBalanced inputs and servo-balancedoutputs withgold-platedXLR connectors, stereo aux output, AES/EBU and S/PDIF inputs and outputs (XLR and optical)

sInternal switch-modepower supply for maximum flexibility (100 - 240 V~),noise-freeaudio, superior transient response and lowest possible power consumption

sDesigned in Germany. Manufactured under ISO9000 certified management system

4

ULTRACURVE PRO DEQ2496

FOREWORD

Dear Customer,

welcome to the team of ULTRACURVE PROusers and thank you very much for expressing your confidence in us by purchasing the DEQ2496.

Writing this foreword for you gives me great pleasure, because it represents the culmination of many months of hard work delivered by our engineering team to achieve a very ambitious goal: to offer you a high-qualitydevice whose flexibility makes it suitable for studio and live applications. The

task of designing our new ULTRACURVE PRO DEQ2496 certainly meant a great deal of responsibility which we assumed by focusing on you, the discerning user and musician. Meeting your expectations also meant a lot of work and night shifts. But it was fun, too. Developing a product usually brings a lot of people together, and what a great feeling it is when all who participated in such a project can be proud of what they’ve achieved.

It is our philosophy to share our enjoyment with you, because you are the most important member of the BEHRINGER team. With your highly competent suggestions for new products you’ve made a significant contribution to shaping our company and making it successful. In return, we guarantee you uncompromising quality as well as excellent technical and audio properties at an extremely reasonable price. All of this will enable you to give free rein to your creativity without being hampered by budget constraints.

We are often asked how we manage to produce such high-qualitydevices at such unbelievably low prices. The answer is quite simple: it’s you, our customers! Many satisfied customers mean large sales volumes enabling us to get better purchasing terms for components, etc. Isn’t it only fair to pass this benefit on to you? Because we know that your success is our success too!

I would like to thank all of you who have made the ULTRACURVE PRO possible. You have all made your own personal contributions, from the developers to the many other employees at this company, and to you, the BEHRINGER user.

My friends, it’s been worth the effort!

Thank you very much,

Uli Behringer

TABLE OF CONTENTS

1. INTRODUCTION .........................................................

6

1.1

Before you get started ...................................................

6

 

1.1.1

Shipment ...............................................................

6

 

1.1.2

Initial operation ......................................................

6

 

1.1.3

Warranty ..............................................................

6

1.2

About this manual ...........................................................

6

2. CONTROL ELEMENTS ...............................................

6

2.1

Front panel ......................................................................

6

2.2

Rear panel ......................................................................

7

3. MENUSTRUCTURE AND EDITING .............................

8

3.1

General operation and display structures .....................

8

3.2

Equalizer modules ..........................................................

8

 

3.2.1 GEQ menu ............................................................

8

 

3.2.2 PEQ menu .............................................................

8

 

3.2.3 DEQ menu .............................................................

9

 

3.2.4 FBD menu ...........................................................

10

3.3

WIDTH menu .................................................................

11

3.4

DYN menu .....................................................................

11

 

3.4.1 LIMITER menu .....................................................

12

3.5

UTILITY menu ................................................................

12

3.6

I/O menu ........................................................................

13

3.7

BYPASS menu ..............................................................

14

3.8

RTA menu (Real-TimeAnalyzer) ..................................

14

 

3.8.1 AUTO EQ function (AEQ) ...................................

15

3.9

MEMORY menu .............................................................

15

3.10 METER menu ...............................................................

16

3.11 RTA/MIC input ..............................................................

16

 

3.11.1Connecting a measurement microphone ...........

16

 

3.11.2Connecting a line signal .....................................

16

4. APPLICATIONS ........................................................

17

4.1

Sum-signalequalizer for live applications ...................

17

4.2

Equalizer in the monitor path ........................................

18

4.3

Using the ULTRACURVE PRO in the studio ..................

18

4.4

Using the ULTRACURVE PRO as a delay unit .............

18

5. CONNECTIONS ........................................................

19

5.1

MIDI connections ..........................................................

19

5.2

Analog connections .....................................................

19

5.3

Digital connections (AES/EBU and S/PDIF) ..................

19

5.4

WORDCLOCK connection ............................................

20

6. OPERATINGSOFTWARE..........................................

20

7. SPECIFICATIONS .....................................................

20

7.1

MIDI implementation .......................................................

21

8. WARRANTY ..............................................................

22

5

ULTRACURVE PRO DEQ2496

1. INTRODUCTION

Thank you very much for expressing your confidence in BEHRINGER products by purchasing the ULTRACURVE PRO DEQ2496, an extremely high-qualityDSP-baseddigital audio processor withbuilt-in24-bit/96kHz A/D and D/A converters, making it an ideal tool for both live and studio applications.

The ULTRACURVE PRO gives you a variety of EQs (graphic, parametric and dynamic) plus a real-timeanalyzer with Auto EQ function, dynamics processors such as compressor, expander and peak limiter and a complete set of analog and digital interface options.

With these and many more features the DEQ2496 is an absolutely all-purposedevice for your recording or mastering studio and will definitely upgrade your live equipment.

+This manual first describes the terminology used, so that you can fully understand the DEQ2496 and its functions. Please read the manual carefully and keep it for future reference.

1.1Before you get started

1.1.1 Shipment

The ULTRACURVE PRO was carefully packed at the factory and the packaging is designed to protect the unit from rough handling. Nevertheless, we recommend that you carefully examine the packaging and its contents for any signs of physical damage which may have occurred during transit.

+If the unit is damaged, please do NOT return it to BEHRINGER, but notify your dealer and the shipping company immediately. Otherwise claims for damage or replacement may not be granted.

1.1.2 Initial operation

Be sure that there is enough space around the unit for cooling and, to avoid overheating, do not place the DEQ2496 on top of power amps or near radiators, etc.

+Blown fuses must be replaced by fuses of the same type and rating. Please refer to the “SPECIFICATIONS” for further details.

The mains connection is made using the enclosed power cord and a standard IEC receptacle. It meets all of the international safety certification requirements.

+Please make sure that all units have a proper ground connection. For your own safety, never remove or disable the ground conductor from the unit or the AC power cord.

1.1.3 Warranty

The DEQ2496’s serial number is located on its top cover. Please take the time to fill in and return the warranty card within 14 days after the date of purchase, so as to benefit from our extended warranty. Or register online at www.behringer.com.

1.2 About this manual

This manual has been designed so that you can get a clear overview of all control elements and at the same time find detailed information on how to use them. If you need more information on specific topics, please visit our web site at www.behringer.com, where we explain effects processing and power amp applications.

2.CONTROL ELEMENTS

2.1Front panel

Fig. 2.1: LED meter and menu keys

The LED METER indicates the DEQ2496’s input signal. The top CLIP LED lights up as soon as the input signal level is too high or the peak limiter in the Dynamics menu (see chapter 3.4) has been activated.

Use the METER key to select the METER menu (see chapter 3.10).

The DEQ2496 features a built-inreal-timeanalyzer displaying the entire frequency range. Use theRTA key to select the corresponding menu and adjust the various settings (see chapter 3.8).

Depending on the currently selected menu, the COMPARE key allows you to compare either complete presets or individual modules. The following table shows how the COMPARE key works in each module:

 

COMPARE

COMPARE

 

(complete

 

(module only)

 

preset)

 

 

 

 

GEQ

 

 

X

PEQ

 

 

X

DEQ

 

 

X

FBD

X

 

 

WIDTH

 

 

X

DYN

 

 

X

UTIL

X

 

 

I/O

 

 

X

BYPASS

X

 

 

RTA

 

not active

MEMORY

X

 

 

METER

 

not active

 

 

 

 

Tab. 2.1: COMPARE function for individual ULTRACURVE PRO modules

Press the MEMORY key to select the MEMORY menu (see chapter 3.9). Here, you can save or recall complete presets or individual modules from one preset (e.g. GEQ, PEQ etc.). The MEMORY LED lights up as soon as the parameter values of the preset selected in the MEMORY menu differ from currently active settings.

Fig. 2.2: Keys, display and rotary controls

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2. CONTROL ELEMENTS

ULTRACURVE PRO DEQ2496

The PAGE key allows you to select the various pages within one menu.

The functions performed by the keys A andB depend on the selected menu and are indicated in the display.

This is the LC display of your ULTRACURVE PRO.

The DEQ2496 has three DATA WHEELS, which can be used to select and edit variousparameters—againdepending on the currently selected menu. Often, they perform a dual function, i.e. you can edit by turning and pressing a data wheel. Pressing the data wheels also changes the scaling of many parameters (step width) or confirms/resets previously made entries.

Fig. 2.3: The menu keys of the DEQ2496

With the menu keys you can select the individual menus of the various modules. They can also be used to select specific pages from these menus (like PAGE key). Each of these keys has a built-inLED, which lights up when the corresponding module starts modifying the sound. When the DEQ2496 receives MIDI data, the LED of the UTILITY key lights up briefly. Keep this key pressed for about 1 s to bypass active modules orre-activatedisabled ones. This function refers only to those modules which can be edited in the BYPASS menu (see chapter 3.7).

Use the POWER switch to put the DEQ2496 into operation. This switch should be set to “Off” before you connect the unit to the mains.

2.2 Rear panel

Fig. 2.4: Mains, MIDI and wordclock connectors

The FUSE HOLDER holds the mains fuse of the DEQ2496. Blown fuses must be replaced by fuses of the same type and rating. Please see the “SPECIFICATIONS” for further details.

The mains connection is made using the enclosed power cord and a standard IEC receptacle.

The MIDI jacks enable the DEQ2496 to communicate with a computer or other MIDI equipment. Incoming MIDI data are received on the MIDI IN, outgoing MIDI data are sent via theMIDI OUT. Received MIDI data are also present at theMIDI THRU jack, so as to pass them on unmodified to other devices.

Use the WORDCLOCK input to synchronize your DEQ2496 to external equipment via a wordclock signal. This connector is on a BNC coaxial jack.

Fig. 2.5: Digital interfaces and RTA microphone input

Your DEQ2496 features a digital optical interface for the transmission/reception of data in both AES/EBU and S/PDIF formats.

The digital AES/EBU interface (XLR connectors) also sends/receives AES/EBU or S/PDIF signals.

The AUX OUT phone jack is an additional stereo output, which allows you to tap the audio signal present at the digital outputs in analog form.

The RTA/MIC IN XLR connector can be used to connect a measurement microphone providing an input signal for thereal-timeanalyzer or SPL meter. This connector has a switchable +15 V phantom power supply for condenser microphones and can be set to microphone or line sensitivity (see chapter 3.11).

The MAX switch raises the maximum level present at the MAIN inputs/outputs from +12 dBu to +22 dBu.

Fig. 2.6: Input and output connectors

These balanced XLR connectors provide the analog output signal of the DEQ2496.

These balanced XLR inputs are used to connect analog input signals.

2. CONTROL ELEMENTS

7

ULTRACURVE PRO DEQ2496

3. MENU STRUCTURE AND EDITING

This chapter provides you with detailed information on how too use the various functions on each menu page. We recommend that you keep this user’s manual available while working with the DEQ2496, so as to use it as a reference in case of any problems.

3.1 General operation and display structures

When you select a menu with the GEQ, PEQ, DYN, etc. keys, the display indicates the respective menu structure. To the left and right along the display you will find functions and parameters for preset editing, which are assigned to the A and B keys (left) and the three data wheels (right) and can be used for editing as required.

Most of the menus comprise several pages. The actual number of pages is shown in the top left part of the display, below the menu name. Use the corresponding menu key or the PAGE key to the left of the display to switch from one page to the next and back again.

As the functions performed by the A and B keys and the data wheels depend on the currently selected menu, all operating steps are described in full detail below. All menus are dealt with one after the other, and all functions and parameters are explained explicitly.

+Please note that the left and right channels will be edited simultaneously in STEREO LINK mode.

3.2Equalizer modules

3.2.1 GEQ menu

Press the GEQ key to enter the GEQ menu. This menu has just one page and allows you to set all filters as desired.

Fig. 3.1: GEQ menu

Turn the upper data wheel to select a frequency band for editing with the FREQ parameter. 31 bands are available comprising the entire frequency spectrum from 20 Hz to 20 kHz. With the large data wheel (GAIN) you can boost or cut the level of the selected band. The setting range is from -15to +15 dB.

VPQ (Virtual Paragraphic Equalizer) function

The lower data wheel (BW/OCT) additionally assigns the required bandwidth to the filters. This means that the frequency bands have a peaking boost/cut characteristic around their center frequency. The number of adjacent frequency ranges influenced by this is determined by the bandwidth. The setting range is from 1/3 too 59/3.

As soon as this parameter has been modified, the RESET GEQ message (left bottom part of display) changes to ACCEPT VALUES. Now, when you press the B key (or the large data wheel), the current value is stored and you can continue to enter the filter settings as required.

When you press the lower data wheel, the BW/OCT parameter changes to MODE. Turn the wheel to select a HIGH or LOW shelving filter. In this case, the GAIN parameter changes to dB/OCT. Use the large data wheel to adjust the filter slope from -15to +15 dB/oct. In HIGH mode, all frequency bands above the selected frequency are now raised or lowered in level. In LOW mode, all frequency bands below that frequency are modified. Confirm your entries with the B key (ACCEPT VALUES).

The A key to the left of the display can be used in DUAL MONO mode to alternate between the left and right-channelaudio signal. Keep the key pressed for some time to display the settings of both sides and edit them simultaneously. In STEREO LINK mode both channels are always processed simultaneously.

The B key allows you to reset the filter settings (RESET EQ). Hit it briefly to reset the currently selected frequency band to 0.0 dB gain. Press it for about 1 s to resetall frequency bands. Single frequency bands can be reset by pressing the large data wheel.

3.2.2 PEQ menu

Press the PEQ key to use parametric EQs for signal processing. On each stereo side, you have ten EQs available, which can be set to PEQ or FBD mode (Feedback Destroyer: see chapter 3.2.4). In addition to the band-passfilters, this menu offers filters of the shelving type (high or low), with a slope of 6 or 12 dB/oct.

Fig. 3.2: PEQ menu (page 1)

This menu comprises two pages, as can be seen in the top left part of the display. Similar to the GEQ menu, page 1 of the PEQ menu provides a graphic representation of the entire frequency range. Parameter changes can be effected with the corresponding controls (FREQ: upper data wheel, GAIN: large data wheel, BW/OCT: lower data wheel).

To reset the selected PEQ, keep the B key to the left of the display pressed for about 1 s. Or hit it briefly to select the parametric filters.

Fig. 3.3: PEQ menu (page 2)

Press the PAGE or PEQ key to select the second menu page. If no parametric EQ was selected before, page 2 will be displayed immediately, providing a list of the ten available locations with all relevant parameters. Single filters can be selected either by turning the lower data wheel or by pressing the lower and upper data wheels (UP/DOWN). MODE allows you to activate the selected filter with the large data wheel (press or turn) (PARAM). This will display the associated parameters FREQ, BW(OCT) and GAIN, which can be selected by turning the upper data wheel. Value changes must be entered with the large data wheel. The GAIN setting range is from -15to +15 dB, the frequency range (FREQ) is from 20 to 20,000 Hz. The FREQ parameter can be adjusted with two scales. The first scrolls faster through the frequency ranges (1/6 oct. per step), the second uses much finer increments (1/60 oct. per step). Press the large data wheel to alternate between these two scales.

The parameter BW(OCT) adjusts the bandwidth of the bandpass filter. The “width” of the peaking characteristic (1/10 oct. to 10 oct.) is determined by this value. Additionally, you can select shelving filters here with a slope of 6 or 12 dB/oct. (e.g. L=Low, 6 dB / H=High, 12 dB, etc.)

Explanation:

The low-shelving filter raises (positive gain) or lowers (negative gain) the level of the frequency bandbelow the adjusted frequency.

8

3. MENU STRUCTURE AND EDITING

ULTRACURVE PRO DEQ2496

The high-shelving filter, on the other hand, raises (positive gain) or lowers (negative gain) the level of the frequency bandabove the adjusted frequency.

The band-pass filter raises or lowers the level of the frequency rangearound the center frequency.

The GAIN and BW(OCT) values can be reset by pressing the large data wheel.

In this menu too, the A keys selects the left and right-channelsignals. If STEREO LINK modes has been selected in the UTILITIES menu (chapter 3.5), the parameter values refer to both sides.

+At least one filter must be activated on page 2 to be able to recall the first page of the PEQ menu.

3.2.3 DEQ menu

Press the DEQ key to select the DEQ menu. Due to their complexity, the Dynamic EQs have their parameters split up on three pages.

Explanation:

A Dynamic EQ influences a defined frequency range of a signal, based on the volume level. It can either raise or lower the level of a specific frequency, depending on the GAIN setting chosen by the user.

When the GAIN setting selected causes the frequency range to be lowered in level, and when the signal exceeds apre-definedTHRESHOLD, the EQ starts processing the sound andcuts the level of the respective frequency range. The amount of attenuation applied is determined by the RATIO parameter. When the signaldrops below the THRESHOLD, the frequency range is “smoothed out” again, i.e. the Dynamic EQ stops processing the frequency range.

When the GAIN setting selected causes the frequency range to be raised in level, this boost depends on the volume level. As soon as the level of the selected frequency rangedrops below apre-definedTHRESHOLD, this results in a signalboost determined by the RATIO parameter. If the signalexceeds the threshold again, the Dynamic EQ stops processing the sound.

On pages 1 and 2 of the DEQ menu you can adjust the necessary settings to determine the threshold and the way of sound processing. Additionally, you will find a graphic representation of the control curve with regard to THRESHOLD, GAIN and RATIO. In the center of the display, the LEVEL meter (left) indicates the filtered DEQ input level (control signal), while the GAIN meter (right) shows how much boost/cut is applied to the signal.

Page 3 includes a frequency diagram showing the filter curves with regard to frequency and threshold. The current DEQ input level can be seen from the LEVEL meter on the right.

Fig. 3.4: DEQ menu (page 1)

The make-upgain parameterM-GAINon page 1 allows you to set the amount of boost/cut for the filter with the upper data wheel. The setting range is from-15to +15 dB. THRESHOLD (large data wheel) defines the threshold as of which the filter function is activated. If the filter has been set to attenuate the signal(M-GAIN< 0), then the desired frequency range (see page 3) will belowered in level as soon as itexceeds the threshold. If boost is required(M-GAIN> 0), the frequency range will beraised in level as soon as the signaldrops below the threshold. The RATIO parameter (lower data wheel) determines the amount of boost/cut applied to the respective frequency range, if the signal exceeds or drops below the threshold. The setting range is from 1:2 to 1:100.

Fig. 3.5: DEQ menu (page 2)

On the second page of the DEQ menu (accessed by pressing the DEQ or PAGE key), you can define two additional dynamics parameters.

ATTACK (upper data wheel) determines how fast the dynamic EQ starts processing when the signal exceeds or drops below the threshold. The ATTACK times available range from 0 to 200 milliseconds. Press this control to select a coarse or fine adjustment scale.

The RELEASE parameter (lower data wheel) lets you adjust the time needed by the EQ to “release” the sound after the signal has exceeded or dropped below threshold (depending on the GAIN setting). The RELEASE times available range from 20 to 4,000 milliseconds. Here, too, you can press the control to select a coarse or fine adjustment scale.

It is on this page that you can also edit the THRESHOLD value (large data wheel), so as to be able to make some readjustments without having to change to another page.

Fig. 3.6: DEQ menu (page 3)

As mentioned before, page 3 includes a frequency diagram and the gain reduction meter. MODE (upper data wheel) defines the filter type, and you can choose from high-shelving,lowshelving andband-passfilters.

The FREQUENCY parameter determines the center frequency of the filter (large data wheel). In the case of low-shelvingandhigh-shelvingfilters, this is thecut-offfrequency as of which the low or high frequencies are processed. The entire frequency spectrum ranges from 20 to 20,000 Hz. Press the data wheel to select a coarse (1/6 oct. per step) or fine adjustment scale (1/60 oct. per step).

If you selected “bandpass” under MODE, the parameter BW(OCT) appears in the lower right part of the display. Here, you can use the lower data wheel to adjust the bandwidth of your choice and thus determine the “width” of the filter curve (1/10 oct. to 10 oct.).

The B key selects which of the dynamic EQs is displayed. Three EQs are available for each stereo side. Keep the key pressed to reset the settings of the currently selected DEQ.

This table shows an example with extreme settings, thus illustrating how a dynamic EQ works:

 

 

 

BP

 

1.00 kHz

 

+15 dB > continuous line

 

0 dB > broken line

 

-15dB > dotted line

 

0.1

 

-40dB

 

1:100

Tab. 3.1: Bandpass with extreme settings (see also fig. 3.7)

3. MENU STRUCTURE AND EDITING

9

ULTRACURVE PRO DEQ2496

Fig. 3.7: Filter curves with signal above/below the threshold

3.2.4 FBD menu

The DEQ2496 features a “Feedback Destroyer” function, which corresponds largely to the PEQ menu as far as operation and choice of parameters are concerned. However, the FBD menu has some additional functions and therefore comprises three pages rather than just two.

The Feedback Destroyer allows you to apply heavy attenuation (no boost) to specific frequency ranges, so as to remove certain frequencies that are liable to cause feedback. With its extermely narrow-bandfilters it hardly affects the overall sound at all.

Fig. 3.8: FBD menu (page 1)

The first page shows a graphic representation of the filters. It is structured and operated in the same way as the first page in the PEQ menu. Since this menu can only be used to cut signals, the 0 dB line is located in the upper part of the display. The differences here are the settings ranges for the GAIN and BW(OCT) parameters. In order to achieve extremely narrowband filters with high attenuation factors, the bandwidth ranges from 1/10 to 1/60 oct. and the GAIN from 0 to -60dB.

+At least one filter must be activated on page 2 to be able to access the first page of the FBD menu.

Fig. 3.9: FBD menu (page 2)

Page 2 provides a table showing the ten memory locations available. If parametric EQs have been activated in the PEQ menu, these will be shown here too, because the memory locations are intended for both FBD and PEQ settings.

+Any parametric EQs activated in the PEQ module cannot be edited in the Feedback Destroyer menu (FBD)—andvice versa.

In general, you can select two types of feedback filters: SNGL mode (single shot) and AUTO mode. To be able to identify feedback frequencies, the Feedback Destroyer splits up the entire frequency spectrum (20 Hz to 20 kHz) into bands of 1/60 octave and measures their respective levels. The resulting values are then referenced to the level of the complete signal. The difference between these levels determines whether a filter is activated or not. As soon as a filter is set to AUTO or SNGL mode, the unit automatically tracks feedback frequencies and assigns the active filters to them.

AUTO mode

Microphones that are moved around during a performance (e.g. vocal mics) often suffer from varying feedback frequencies as a result of the changing positions on stage. This kind of feedback is best suppressed in AUTO mode. A filter in AUTO mode automatically identifies the optimum parameter settings for feedback suppression. If the feedback frequencies change, the AUTO filter can track them and keep suppressing them. It always selects the respective frequencies and a very narrow-bandfilter configuration to affect the wanted signal as little as possible. When all filters are locked in to a specific frequency, and a “new” feedback frequency occurs, then the filter with the “oldest” or first feedback frequency detected is released and used for the new one. If new feedback occurs very close to or even at an already identified frequency, the parameters of the filter already in use will be adapted, for example by widening its bandwidth or raising the amount of signal attenuation.

SNGL mode

Filters in SNGL mode (single shot) also searches feedbacks automatically. If feedback is identified, the filter parameters are configured optimally for feedback suppression. Contrary to filters in AUTO mode, filters in SNGL mode lock in firmly to the identified frequency (LOCK FBD), however, their width and depth are still being adapted to changes in the feedback frequencies. The bandwidth is enlarged, if the feedback frequency shifts slightly, and the amount of attenuation is raised if feedback persists. To prevent a feedback frequency from recurring, the amount of attenuation is not reduced. Thus, SNGL mode is ideally suited to suppress constant feedback frequencies, as they are typically produced by fixed or permanently installed microphones.

Use the LOCK FBD function (B key in the left bottom part of the display) to lock the frequency of the SNGL filter manually (SNGL Ï). This means that the filter can only be modified in its bandwidth and amount of attenuation. With UNLOCK FBD (B key) it can be unlocked again.

Fig. 3.10: FBD menu (page 3)

The third page provides three additional dynamics parameters for all FBD filters.

SENS (upper data wheel) allows you to determine the point of onset for feedback suppression (describes the difference between feedback signal and overall level). When a signal reaches this difference, it gets reduced in level. The setting range here is from -3.0to-9.0dB. Use THRESHOLD (large data wheel) to select the threshold from which a certain frequency is considered to be feedback. The MAX. DEPTH parameter below determines the maximum attenuation of a filter(-18to-60dB) in 6 dB steps, and thus the GAIN setting range as displayed on the first and second page (lower data wheel).

LEARN MODE is activated with the A key. This function generates additional short pulses and raises the overall gain to provoke feedback. Subsequently, the feedback signals arrive at the input of the DEQ2496, are identified and suppressed. LEARN MODE is ideal for use before a live event, for example to automatically configure the SNGL filters (“tuning-in”of a P.A. system).

The following symbols inform you about the current status of the filters:

;In this setting, an AUTO or SNGL filter is “on duty” (RUN) to react to the incoming signal and effect the necessary settings.

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3.MENU STRUCTURE AND EDITING