Reference Manual
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Table Of Contents Introduction ..................................................................3 Welcome!...................................................................................................... 3 DEQ830 Key Features .................................................................... 4 How to Use This Manual................................................................ 5 Important Safety Instructions..................................7 Important Safety Instructions (English) ..............
Table Of Contents Basic operation: Edit mode........................................................... 34 Basic operation: Store mode......................................................... 41 Basic operation: Save Curve mode ............................................. 41 Basic operation: Retrieve Curve mode ...................................... 41 Basic operation: Channel Level mode........................................ 42 Basic operation: Link mode..................................................
Introduction Welcome! Thank you for purchasing the Alesis DEQ830. It is a versatile product, and whether it becomes a part of your studio or finds its place in your live setup, we know it will serve you well. Since 1984, we’ve been designing and building creative tools for the audio community. We believe in our products, because we've heard the results that creative people like you achieve with them. One of the goals of Alesis is to make high-quality music technology available to everyone.
Introduction DEQ830 Key Features 1. Offers the best of digital technology and analog-style control: a graphic display with instant editing of any band or combination of bands, plus the ability to store programs 2. 100 user-definable programs, each of which holds 8 channels of EQ settings 3. 100 user-definable curves, each of which holds 30 bands of EQ settings 4. 48 KHz sampling rate, 24-bit A/D/A, 28-bit internal processing 5. Eight channels of equalization, independent or linkable 6.
Introduction How to Use This Manual This manual is divided into the following sections describing the various functions of and applications for the DEQ830. While it's a good idea to read through the entire manual once carefully, those having general knowledge about audio equipment should use the table of contents to look up specific functions. Chapter 1: Quick Start Guide. If you're already familiar with equalization, this will get you started using the DEQ830 right away.
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Important Safety Instructions Important Safety Instructions (English) Safety symbols used in this product This symbol alerts the user that there are important operating and maintenance instructions in the literature accompanying this unit. This symbol warns the user of uninsulated voltage within the unit that can cause dangerous electric shocks. This symbol warns the user that output connectors contain voltages that can cause dangerous electrical shock.
Important Safety Instructions 12. Use only with a cart, stand, bracket, or table designed for use with professional audio or music equipment. In any installation, make sure that injury or damage will not result from cables pulling on the apparatus and its mounting. If a cart is used, use caution when moving the cart/apparatus combination to avoid injury from tip-over. 13. Unplug this apparatus during lightning storms or when unused for long periods of time. 14.
Important Safety Instructions Instructions de Sécurité Importantes (French) Symboles utilisés dans ce produit Ce symbole alèrte l’utilisateur qu’il existe des instructions de fonctionnement et de maintenance dans la documentation jointe avec ce produit. Ce symbole avertit l’utilisateur de la présence d’une tension non isolée à l’intérieur de l’appareil pouvant engendrer des chocs électriques.
Important Safety Instructions 12. N’utilisez qu’avec un stand, ou table conçus pour l’utilisation d’audio professionnel ou instruments de musique. Dans toute installation, veillez de ne rien endommager à cause de câbles qui tirent sur des appareils et leur support. 13. Débranchez l’appareil lors d’un orage ou lorsqu’il n’est pas utilisé pendant longtemps. 14. Faites réparer par un personnel qualifié.
Important Safety Instructions Lesen Sie bitte die folgende Sicherheitshinweise (German) Sicherheit Symbole verwendet in diesem Produkt Dieses Symbol alarmiert den Benutzer, daß es wichtige Funktionieren und Wartung Anweisungen in der Literatur gibt, die diese Maßeinheit begleitet. Dieses Symbol warnt den Benutzer der nicht isolierten Spannung innerhalb der Maßeinheit, die gefährliche elektrische Schläge verursachen kann.
Important Safety Instructions 12. Verwenden Sie ausschließlich Wagen, Ständer, oder Tische, die speziell für professionelle Audio- und Musikinstrumente geeignet sind. Achten Sie immer darauf, daß die jeweiligen Geräte sicher installiert sind, um Schäden und Verletzungen zu vermeiden. Wenn Sie einen Rollwagen benutzen, achten Sie darauf, das dieser nicht umkippt, um Verletzungen auszuschließen. 13.
Important Safety Instructions CE Declaration of Conformity See our Web site at: http://www.alesis.com FCC Compliance Statement This device complies with Part 15 of the FCC rules. Operation is subject to the following two conditions: (1) This device may not cause harmful interference and (2) this device must accept any interference received, including interference that may cause undesired operation.
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1 Quick Start Guide If you can’t wait to get started… The Alesis DEQ830 is a unique product, but its basic hookup and operation are similar to other equalizers in most respects. If you're experienced with signal processors, this chapter is a “shorthand” guide for those who want to start using the DEQ830 right away. If you have questions about any of the features, don’t worry – all the details will be covered in later chapters.
1 Quick Start Guide Step 2: Try some equalization Play some signal into the unit While learning the unit, you should play a CD or a multitrack source into the equalizer. Choose a song or musical passage with a fairly consistent level, so you can take your time experimenting with the different features. 1. Put the mixer’s main faders all the way down so you don’t distort the unit by sending it too much signal. 2. Select program 00 on the DEQ830.
Quick Start Guide 1 Step 4: Save an EQ Curve In addition to being able to save entire programs, you can also save the settings for an individual EQ curve. Here’s how to do this: 1. Select the curve you wish to save by pressing that channel’s [CHANNEL SELECT] button. 2. Press the [SAVE CURVE] button to enter Save Curve mode. 3. Use the [VALUE] encoder to select the new location for the edited curve.
1 Quick Start Guide DEQ830 Diagram 18
2 Connections Unpacking and Inspection Your DEQ830 was packed carefully at the factory. The shipping carton was designed to protect the unit during transit. Please keep this carton in the highly unlikely event that you need to return the DEQ830 for servicing.
2 Connections AC Power Hookup The DEQ830 has what’s known as a “switching power supply.” This means it will detect any standard line voltage from 90 to 230 volts, 50-60 Hz, and adapt itself to that. All you need is the proper AC cable for the country in which you find yourself. Just plug the "female" end of the power cable into the DEQ830’s POWER receptacle and the “male” end into a good quality, noise-free AC power source.
Connections 2 Connecting Inputs and Outputs Connecting to the Channel or Main Inserts of a mixing console Unbalanced I/O Most mixing consoles have insert jacks near the main outputs and for each channel as well. These are typically Tip-Ring-Sleeve (TRS) jacks with the send and return on the same jack. To use the DEQ830 as an effects insert device, you will need an insert cable (not included). This cable splits the TRS insert jack into two unbalanced mono connectors.
2 Connections Mono connections This example shows how to connect the DEQ830 to one mono source. You can use this method to connect eight mono sources to the DEQ830. You would need eight insert cables to make all of these connections. Stereo connections Use two insert cables to connect the DEQ830 to the main L/R bus in the same way you would connect it to a pair of channel inserts.
Connections 2 Connecting to the inserts on an instrument amplifier Unbalanced I/O The insert sends on a guitar or bass amp are usually labeled “effects send and return” or “insert send and return.” This allows your instrument to be boosted to line level before the signal is sent to the equalizer, processed, and returned to the power amp. If you are using a two-piece system, another method would be to insert the DEQ830 between the preamp and the power amp.
2 Connections Analog Signal In, Digital Signal Out In this configuration, the DEQ830 can be used to “translate” an analog signal to the digital domain. A likely scenario would be using the DEQ830 as an analog-to-digital converter between your submix outputs and an Alesis ADAT. In addition to acting as a “gateway,” the DEQ830 would allow you to shape the sound and send it to the ADAT digitally, without the additional noise that can be added by an analog EQ.
Connections 2 About Audio Cables The connections between the DEQ830 and your studio are your music’s lifeline, so use only high quality cables. These should be low-capacitance shielded cables with a stranded (not solid) internal conductor and a low-resistance shield. Although quality cables cost more, they do make a difference. Route cables to the DEQ830 correctly by observing the following precautions: • Do not bundle audio cables with AC power cords.
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3 Basics of Equalization This section will describe how equalization works and explain the functions of the DEQ830’s controls. What is equalization? An equalizer boosts or cuts a frequency range. The DEQ830 is a graphic equalizer, which means it has many fixed frequency bands that can be cut or boosted. The term “graphic” is appropriate because the combined settings of the bands often resemble a curve, or “graph.
3 Basics of Equalization Description of the Front Panel This section will give you an overview of the front panel’s features. Not all features are labeled, so you may want to refer to the diagram of the DEQ830 on page 18 as you read this section. Band Select There are 31 buttons side-by-side on the left half of the DEQ830’s front panel. The first 30 are the [BAND SELECT] buttons. Above each of the [BAND SELECT] buttons is a number like “25” or “8k.
Basics of Equalization 3 the original signal so you can decide if you like the edit you made. Press the button again to get out of Bypass mode and hear the effect. Bypass All (ALL) This button is located just above the [BYPASS] button. It will toggle the Bypass status of all eight channels at once. The first press of the [ALL] button will cause any unbypassed channels to enter Bypass mode. Subsequent presses will toggle the Bypass status of all eight chanels together.
3 Basics of Equalization Program If you want to cancel any action in progress and return to Program mode, just press the [PROGRAM] button. Value Encoder (VALUE) On far right side you’ll find a knob marked [VALUE], which is used to edit the gain amount of the frequency you have selected with the [BAND SELECT] buttons. (It is also possible to select and edit several frequencies at once, as you’ll see later.
Basics of Equalization 3 Description of the Basic Modes Program mode When this manual refers to Program mode, we mean the very top level of functionality of the DEQ830. In program mode, turning the [VALUE] encoder will let you select between the 100 userdefinable preset programs in the unit. A program consists of more than just EQ settings.
3 Basics of Equalization works well for male vocals. Say you have two or three channels of male vocals feeding into the DEQ830. To EQ these, just retrieve the curve from the Curve Bank, apply it to each male-vocal channel and modify it slightly to fit each particular vocal. Curve 00 is a “flat” curve. We recommend that you leave Curve 00’s gain settings at 0 so that you may use it as a “clean slate” for building new curves from the ground up. For information on how to do this, see page 41.
Basics of Equalization 3 Link mode In this mode, you can link multiple channels so that their EQ settings are locked together. To experiment with this, first select a channel with recognizable settings. Next, press and hold down the [LINK] button. You can then select channels to link to the original channel by pressing their [CHANNEL SELECT] buttons. You will see the Band Gain LEDs for each linked channel change to match the settings of the currently selected channel.
3 Basics of Equalization Basic operation: Program mode Program mode is where to be if you want to call up another program, or if you just want to know the number of the program you are using. The DEQ830 has 100 programs in all. Programs 0024 contain factory presets that you can use as starting points for your own programs. You can overwrite any of the 100 programs. Navigation in Program mode is a breeze. First, if you’re not in Program mode, get there by pressing the [PROGRAM] button.
Basics of Equalization 3 Band Solo The DEQ830 has a handy feature called Band Solo that allows you to “isolate” a given frequency while you are editing. This can help you determine exactly which band you need to highlight or deemphasize. It’s simple to do: 1. Select a band by pressing and holding its [BAND SELECT] button. 2. Press the [VALUE] encoder. You’ll see the LED for that band jump to +12 dB. 3. Press the [VALUE] encoder again. The LED for that band will jump to –12 dB. 4.
3 36 Basics of Equalization LED Gain Change + 12 dB 11.5 – 12.0 dB + 10 dB 9.5 – 11 dB + 8 dB 7.5 – 9.0 dB + 6 dB 5.5 – 7.0 dB + 4 dB 3.5 – 5.0 dB + 2 dB 0.5 – 3.0 dB 0 dB 0 dB - 2 dB 0.5 – 3.0 dB - 4 dB 3.5 – 5.0 dB - 6 dB 5.5 – 7.0 dB - 8 dB 7.5 – 9.0 dB - 10 dB 9.5 – 11 dB - 12 dB 11.5 – 12.
Basics of Equalization 3 Multiple Band Edit Selecting an Edit Group Pressing a [BAND SELECT] button puts the DEQ830 into Edit mode. And until you turn the [VALUE] encoder to boost or cut the gain, you can keep pressing [BAND SELECT] buttons until you have several of them selected simultaneously. This is called selecting an Edit Group. An Edit Group can be made up of any number of bands. Another way to select an edit group is to hold down a [BAND SELECT] button and turn the encoder.
3 Basics of Equalization (see fig. 1 on page 38). But it won't stop at 12; it will keep racing upward until it reaches 24. This is because that’s how far the band that was set to -12 dB had to travel until it hit the “ceiling,” or + 12 dB (see fig. 2). But what about the band that was set to 0 dB originally...was it boosted to +24 dB? The answer is, “Yes and no.
Basics of Equalization 3 One important note, though: Proportional Gain Memory is only temporary. If you run one or more bands “past” the +/-12 dB limit and then you exit Edit mode for any reason (such as to store the program), the gain value of those bands will be remembered as +/-12 dB (whichever was the value that was last reached for those bands). The limits of Relative Gain There will be times when the Relative Gain display will not go all of the way up or down to a value of 24.
3 Basics of Equalization Likewise, if the lowest gain setting of any band in this same Edit Group is -4 dB, then the largest number you will see in the Relative Gain display going all the way up is 16 (see fig. 5). So if you run the Relative Gain display up and down repeatedly with this Edit Group, the display will hit the "ceiling" at 16 and bottom out at 18.
Basics of Equalization 3 Basic operation: Store mode Once you have created a program you would like to save, press the [STORE] button to enter Store mode. This will cause the Numerical LED Display to blink with the number of the current program. Turning the [VALUE] encoder allows you to choose a program number between 00-99 as the destination for your edited program. Once you have chosen the location you want, press the [STORE] button again or just press the [VALUE] encoder.
3 Basics of Equalization Copying settings between channels You can use the Link function while editing to help set up identical curves on multiple channels. But at some point the curves may need to diverge slightly (or significantly). Rather than unlinking the channels and starting all over again, you can use the Curve Bank to “bounce” the settings from one channel to another. Then you can begin diversifying the settings of the channels to match the needs of the incoming audio.
Basics of Equalization 3 Remember that a non-primary channel is “mirroring” the settings of the primary channel. When you perform an edit on a nonprimary channel, you aren’t actually editing that channel; you are actually changing the primary channe, and the audio for all linked channels will be affected by the edit. But whatever settings existed on the non-primary channel before it was linked will still be there when you unlink it.
3 Basics of Equalization Metering modes The DEQ830 allows you to choose how the Band Gain LEDs will respond in RTA mode. This is done in Utility mode, where you can use the [VALUE] encoder to select between the four different settings of the Peak Mode function, as shown in the chart below. Displayed Setting Name Description 0 No Hold Peaks are not held. 1 1 Second Peaks are held for one second. 2 2 Seconds Peaks are held for two seconds.
Basics of Equalization Basic operation: Utility mode This is where you will find some of the features that govern the way the DEQ830 operates in the other modes. They are what you would call “global” settings, in that their status is not stored with a program. No matter which program you call up, these settings will not change. Press the [UTILITY] button to access Utility mode. Pressing it repeatedly will cycle through all of the functions that you may edit in this mode.
3 Basics of Equalization When a hot line level signal comes in, the DEQ830 has plenty of headroom to deal with it. But if you perform some radical equalization on this signal, it is possible that the combination of the incoming hot signal plus the equalization you have done may put the signal “over the top” and within clipping range. The Master Level function allows you to reduce the level of the equalized signal before it reaches the final output stage of the DEQ830.
Basics of Equalization 3 There are pros and cons to both ways of working. So, experiment with this feature and see which way works best for you. To enable or disable the Release Edit Group feature from this Utility mode page, just turn the [VALUE] encoder. Edit Time Out (On/Off) The Edit Time Out function serves as an “auto-exit” feature. When it is enabled, if you do not change the gain value of any band or Edit Group for 30 seconds, the DEQ830 will exit automatically to Program mode.
3 Basics of Equalization command is initiated (Button 11), the sys-ex data will be sent in either case. Internal Clock Sample Rate Select (44.1/48) The DEQ830 automatically senses an incoming digital signal through its ADAT Optical input and slaves its internal clock to that, whether the rate is 44.1k or 48k. But if you need the DEQ830 to serve as an A/D converter, then it will need to be the master clock for the receiving device. You may prefer to record the output of the DEQ830 at either 44.1k or 48k.
Basics of Equalization 3 This process is not affected by the setting of the MIDI Out/Thru Select function. When you instruct the unit to Transmit, the sys-ex data will be sent whether the MIDI jack is set to Out or Thru. Receiving System Exclusive bulk dumps The DEQ830 is always ready to receive a new bank of programs and curves into its internal memory. Once an external device begins sending the proper sys-ex data, the DEQ830 will display the message “Rcving,” short for “receiving.
3 Basics of Equalization The "Hidden" Modes There are a couple of sub-levels of operation that can be accessed by pressing different buttons. We covered a number of modes on the preceding pages; here are two more “hidden” modes: Demonstration mode Sometimes it’s fun to have a lot of little lights flashing from the stage or in the studio. The DEQ830 has a special key combination that will activate a “fireworks display” for the entertainment of your clients, audience, or children.
Basics of Equalization 3 Equalization Artifacts When you apply a lot of EQ (6dB or more), you may hear some consequences on the output. Here are a few common side effects to applying a lot of equalization and some ways to avoid them. Distortion If you boost too many frequencies too high, you will distort the output. If this happens, the channel’s red CLIP LED will light. To avoid this, turn down the signal being sent to the DEQ830.
3 Basics of Equalization Constant Q vs. Variable Q What makes the DEQ830 unique? Early graphic equalizers relied solely on a form of equalization known as “Variable Q.” The DEQ830, on the other hand, is what is known as a “Constant Q” equalizer. This method of equalization is a relatively recent development in the history of sound reinforcement and recording technology.
Basics of Equalization 3 Variable Q In the next illustration, the wider and more gradual curve represents a lower gain setting for a Variable Q equalizer. The narrower and more steep curve represents a higher gain setting at the same frequency: The previous illustration has been exaggerated somewhat to make the point, but you can see how a lower gain setting also boosts frequencies that overlap to some extent into the regions affected by the next highest and lowest frequency band controls.
3 Basics of Equalization Multi-band application and results So far we have only dealt with cutting or boosting single frequency bands. The differences between the Constant Q and Variable Q methods become more “graphic,” if you will, when adjacent frequency bands are involved. In this example, three adjacent bands are used.
Basics of Equalization 3 To further illustrate the differences, here is a pair of examples in which three adjacent bands have settings of + 3 dB, -3 dB, and + 3 dB, respectively: Remember that at lower gain settings, there is an even wider Q for a given frequency band on a Variable Q equalizer. The center frequency band needs to be edited even more drastically in order for any noticeable reduction of frequencies in its range.
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4 Applications This section is designed to get you started with the DEQ830 by giving some sample settings. These are merely suggested settings; experiment and find your own once you begin to hear what the DEQ830 does to your sound. In a way, it’s absurd to suggest EQ settings without knowing what the source sounds like. EQ is a tool that’s used to change the timbre of a sound, and it’s impossible to suggest an EQ setting that, for example, will make all guitars sound better.
4 Applications Eliminating Feedback During a live performance, you may experience feedback if a microphone is placed too close to a monitor. However, this feedback often occurs at one frequency before it happens at others. You can "ring out" the monitor by using EQ to cut the frequency that’s feeding back. The following is best to try when the band and audience are not present: 1. Insert the EQ between the mixer’s monitor output and the monitor amplifier. 2.
Applications 4 Comb filtering You'll understand how this effect process got its name once you see the way it looks when recreated on the DEQ830. This one works especially well with two channels that carry the left and right signals from a stereo audio source: 1. Starting from the far left of the band spectrum, press every other [BAND SELECT] button and take those bands all the way down to -12 dB. Then select the unedited bands and boost them +6 dB.
4 60 Applications
5 Troubleshooting Line Conditioners and Protectors Although the DEQ830 is designed to tolerate typical voltage variations, in today’s world the voltage coming from the AC line may contain spikes or transients. These can cause audible noises, and they can stress your gear and, over time, possibly cause a failure. There are two main ways to protect against this, listed in ascending order of cost and complexity: • • Line spike/surge protectors.
5 Troubleshooting Troubleshooting Index Symptoms No audio at outputs. Cause No input audio. Bad cables. Destination is turned down. Weak output signal. Input level weak. Output level weak. Clip LED lights often. (Decide which is the case by pressing the Bypass button.) Input level too high. Output level too high. (Decide which is the case by pressing the Bypass button.) 62 Can’t select new program, display keeps blinking. Program Fast is set to “Off.” Can’t edit program, can’t select new program.
Troubleshooting 5 Refer All Servicing to Alesis We believe that the DEQ830 is one of the best signal processors that can be made using current technology, and should provide years of trouble-free use. However, should problems occur, DO NOT attempt to service the unit yourself unless you have training and experience. Service on this product should be performed only by qualified technicians. NO USER-SERVICEABLE PARTS INSIDE.
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Specifications Rear Panel I/O (switchable) Analog: Input Connectors: Output Connectors: 8 balanced 1/4” TRS jacks 8 balanced 1/4” TRS jacks Digital: Input Connector: Output Connector: 1 ADAT Optical 1 ADAT Optical Switch set to +4: Nominal input level: Maximum input level: +4dBu (-15dBFS) +19dBu (6.9 Vrms) Nominal Output Level: Maximum Output Level: +4dBu (-15dBFS) +19dBu (6.9 Vrms) Switch set to –10: Nominal input level: Maximum input level: -10dBV (-16dBFS) +6dBV (2.
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Warranty / Contact Alesis Limited Warranty ALESIS CORPORATION ("ALESIS") warrants this product to be free of defects in material and workmanship for a period of one (1) year for parts and for a period of one (1) year for labor from the date of original retail purchase. This warranty is enforceable only by the original retail purchaser and cannot be transferred or assigned. For the most effective service, the purchaser should register the purchase on the ALESIS website at http://www.alesis.
Warranty/Contact Alesis Contact Information Alesis Distribution, LLC Los Angeles, CA USA E-mail: Website: support@alesis.com http://www.alesis.com Alesis DEQ830 Reference Manual Revision A by Randy Lee, Taiho Yamada and Edwin Erdmann Revision B by Bret Victor Copyright 2003, Alesis Distribution, LLC. All rights reserved Reproduction in whole or in part is prohibited. Specifications subject to change without notice.
