Helpful tips and advice are highlighted in a shaded box like this.
The names of specific buttons on the DEQ830 are printed in a bold font and bracketed: e.g., the [BYPASS] button.
When something important appears in the manual, an exclamation mark (like the one shown at left) will appear with some explanatory text. This symbol indicates that this information is vital when operating the DEQ830.
This page intentionally left blank.
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.
Please follow these precautions when using this product:
Read these instructions. Keep these instructions. Heed all warnings. Follow all instructions. Do not use this apparatus near water. Clean only with a damp cloth. Do not spray any liquid cleaner onto the faceplate, as this may damage the front panel controls or cause a dangerous condition. 7. 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-type plug. 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. When 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, convenience receptacles, and the point where they exit from the apparatus. 11. Use only attachments or accessories specified by the manufacturer. Continued next page 1. 2. 3. 4. 5. 6.
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. Refer all servicing to qualified service personnel. Servicing is required when the apparatus has been damaged in any way, such as when the power-supply cord or plug is damaged, liquid has been spilled or objects have fallen into the apparatus, the apparatus has been exposed to rain or moisture, does not operate normally, or has been dropped. 15. This unit produces heat when operated normally. Operate in a well-ventilated area with at least six inches of clearance from peripheral equipment. 16. This product, in combination with an amplifier and headphones or speakers, may be capable of producing sound levels that could cause permanent hearing loss. Do not operate for a long period of time at a high volume level or at a level that is uncomfortable. If you experience any hearing loss or ringing in the ears, you should consult an audiologist. 17. Do not expose the apparatus to dripping or splashing. Do not place objects filled with liquids (flower vases, soft drink cans, coffee cups) on the apparatus. 18. WARNING: To reduce the risk of fire or electric shock, do not expose this apparatus to rain or moisture. 19. The unit is an audio device, whose power supply may be subject to surrounding electronic interference. Once installed, if you find that the unit is malfunctioning, the problem may be solved by resetting the unit, relocating the unit, or by installing a line-conditioner.

If your mixer does not have insert jacks available at its main outputs, simply connect the main outputs of your nonpowered mixer to the inputs of the DEQ830, then connect the outputs of the equalizer to the inputs of your mixdown recorder or amplified monitoring system.

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. Simply connect one insert cable to the left main insert of the mixer, and connect the two mono jacks to the Channel 1 input and output of the DEQ830. Use another insert cable to connect the right main insert to the Channel 2 input and output of the DEQ830. You can also simply connect the balanced main outputs of the mixer to the inputs of the DEQ830, then connect the outputs of the equalizer to the inputs of your mixdown recorder, monitor system, etc.
Since the DEQ830 has eight channels, you can connect eight independent sources. For example, you could use Channel 1 to EQ the rhythm guitar, Channel 2 to EQ the bass guitar, Channels 3 and 4 to EQ the left and right outputs of a keyboard, and so on.
Never place the equalizer between the power amp and the speakers, as the highpowered levels created by the power amp will damage the DEQ830.

Balanced I/O

Some recording consoles have separate balanced jacks for the sends and returns instead of a single TRS jack. If your recording console has these connections, use a balanced TRS cable to connect the insert send to the input of the equalizer, and another balanced TRS cable to connect the equalizer output to the insert return.
Modern production values sometimes lead to the heavy use of compression during the mastering process. When processing CD audio, you may find it necessary at times to lower the Channel Level of the active program so as to avoid clipping the output stage of the DEQ830. This will allow additional headroom for more extensive equalization. See pg. 32 for details on the Channel Level function.

Basics of Equalization

Description of the Front Panel
This section will give you an overview of the front panels 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 DEQ830s front panel. The first 30 are the [BAND SELECT] buttons. Above each of the [BAND SELECT] buttons is a number like 25 or 8k. These stand for the audio frequencies, measured in Hertz (Hz), which are selected for editing by the [BAND SELECT] buttons below them. The 31st button is the [CHANNEL LEVEL] button, which is explained below.

Channel Level

The [CHANNEL LEVEL] button is used to set the level of the currently selected channel or Link Group. This setting is post-EQ and pre-Master Level.
For details on the relationship between Master Level and Channel Level, see page 32.

Real Time Analyzer (RTA)

This button will put the DEQ830 into Real Time Analyzer mode, in which the unit serves as a visual aid for analyzing the audio signal. In this mode, the Band Gain LEDs dance to the music, displaying the relative strengths of the various frequency ranges passing through the DEQ830. For more on this mode, see page 43.

Channel Select

To the right of the [POWER] button, youll see the [CHANNEL SELECT] buttons. These eight buttons are used for selecting a channel for which the EQ settings will be displayed on the 30 Band Gain LEDs. The [CHANNEL SELECT] buttons are also used for creating Link Groups.
Monitor Select (INPUT/OUTPUT)
This button, located immediately above the [BYPASS] and [ALL] buttons, toggles between INPUT and OUTPUT to determine whether the Channel Meters and RTA display the input or output levels. The green LEDs above this button indicate which monitoring method is currently selected.

Bypass

When you press this button, a red LED will light immediately above the currently selected channel, indicating that this channel is in Bypass mode. As long as this LED is lit, incoming audio will pass through this channel without being affected by its EQ settings. Also, if youre on a linked channel when you press the [BYPASS] button, all of the linked channels will bypass at the same time. Bypass mode is useful for comparing the equalized signal with
Bypass mode hides the effect of the EQ and Channel Level controls on the audio. However, the Master Level function from Utility mode is unaffected by the [BYPASS] button. For more information about the relationship between Channel Level and Master Level, see page 32.
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.

Numerical LED Display

The three-digit LED display you see to the left of the [VALUE] encoder is always showing either a value or an abbreviated name. To help you know at a glance what sort of information the display is giving you, there are three green LEDs immediately below the Numerical LED Display: PROG If this LED is lit, this means the value in the display is a program number. You will see this when the unit is in Program mode or Store mode. When lit, this LED indicates that the number in the display is telling you which curve has been chosen. This LED tells you that the value in the display pertains to a gain change.
The only time that none of these LEDs will be lit is when the DEQ830 is in Utility mode.
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. The things stored in memory and recalled when you select a program are: The gain settings of all 30 bands for channels The Link status of all 8 channels The actual gain settings for all non-primary channels in a Link Group. These are merely hidden by the Link function. The individual Channel Level settings for channels 1 8
If the DEQ830 has been in some other mode, pushing the [PROGRAM] button will return it to Program mode. If the LED above the [STORE] button is flashing, that means the program has been edited. If youve made any changes that you would like to keep, be sure to save them before switching to another program! To learn how to store an edited program, turn to page 41.

Edit mode

While in Program mode, pushing one of the [BAND SELECT] buttons will take you to Edit mode. You can tell you are in Edit mode when one or more of the LEDs above the [BAND SELECT] buttons are blinking. The bands with blinking LEDs are the ones that will be boosted or cut when you turn the [VALUE] encoder. After you have edited a frequency or an Edit Group (a group of frequencies), pushing the [PROGRAM] button will return you to Program mode. If youve made any changes, the LED above the [STORE] button will be flashing. Be certain to save any changes that you would like to keep! This is where Store mode comes in.

Store mode

Pressing the [STORE] button takes you to Store mode. From here you can decide which of the 100 program locations will become the new home for the edited program. For information on how to perform this procedure, see page 41.

Save Curve mode

Pressing the [SAVE CURVE] button takes you to Save Curve mode. This lets you save an edited EQ curve to one of the 100 memory locations in the DEQ830s curve bank. These curves can be recalled later and applied to any channel of any program. You can use the Curve Bank to save templates for all possible EQ applications. For example, you can save an EQ curve that generally
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. For information on how to do this, see page 41.
Curve 00 is a flat curve. We recommend that you leave Curve 00s gain settings at 0 so that you may use it as a clean slate for building new curves from the ground up.

Retrieve Curve mode

This mode allows you to take a stored EQ curve from the Curve Bank and place it into the currently selected channel or Link Group. For information on how to do this, see page 41.

Bypass mode

This mode is nearly as simple as it soundspushing the [BYPASS] button will let you hear the non-equalized audio. But theres a bit more to it than that. There are also two gain adjustment stages that can be used to compensate for a reduction or increase in signal level caused by the equalization curve being used. The value for one of these stages, Channel Level, is saved along with the EQ settings when the program is stored; the value for the other stage, Master Level, is not. So what Bypass mode really is doing is causing the audio to pass by the processing stages that are stored as a part of the program. The following diagram shows the relationship between each of the stages in the DEQ830s signal processing chain.
Youll find a description of Channel Level mode further down on this page. For a description of the Master Level function, turn to page 44.

Channel Level mode

When you run a number of different instruments into the DEQ830, each channel may experience drastically different signal levels. Channel Level mode can be used to adjust the output of each channel independently. This mode is also useful when processing a stereo signal. If the combination of the source material and extreme EQ settings is causing the output of the DEQ830 to clip, Channel Level mode can be used to adjust the output of two stereo channels simultaneously. To do this, the two channels must be linked. See page 42 for more details on Link mode.

Just as Program 00 is a flat program, Curve 00 is a flat curve. We strongly recommend that you leave Curve 00s gain settings at 0 so that you may use it as a clean slate for building new curves from the ground up.

Single Band Edit

Pressing a [BAND SELECT] button puts the DEQ830 into Edit mode. The Numerical LED Display will now display the gain value in decibels (dB) of the band you just selected. In addition, one of the Band Gain LEDs above that [BAND SELECT] button will start blinking. If the gain value of that band is 0 dB, the green LED will blink. This means there is no gain change occurring in this frequency range. If it is higher or lower than that, one of the yellow LEDs will blink. This indicates that some amount of cut or boost is happening. Use the [VALUE] encoder to change the gain value of that band. Turning the [VALUE] encoder left will lower the gain value, or cut the chosen frequency; turning it right will raise the gain value, or boost the frequency. There is an overall range of +/- 12 dB of gain change available.
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. Its simple to do: 1. Select a band by pressing and holding its [BAND SELECT] button. 2. Press the [VALUE] encoder. Youll 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. Release the [BAND SELECT] button, and the value of that band will be returned to its original setting. This only works with one band at a time, but youll find it to be a very helpful feature. To exit Edit mode, press the [PROGRAM] button. This will return the DEQ830 to Program mode. Band Gain Cut/Boost Ranges Whether you are cutting or boosting a band, gain change happens in 0.5 dB increments. As you make the change, the Numerical LED Display will show you the magnitude of the gain: 0.5, 1.0, 1.5, 2.0,. up to 12.0. Because its not possible to show a minus sign in the LED display for negative gain values, youll see the same sequence as you turn the encoder to the left. But if theres any doubt in your mind about which way youre going, the Band Gain LED will clue you in. As soon as you move 0.5 dB away from 0, the LED for that band will change from green to yellow. If you are cutting the frequency, youll see a yellow light below the center line. If you are boosting it will be above. Since the front panel only has thirteen gain LEDs to represent the 49 possible levels of gain in each band, you may not see the LED change when you make small adjustments to the gain. The table on the following page shows the amount of change in dB it takes to light each of the Band Gain LEDs:

When you enter Save Curve mode, RTA mode is exited. When you finish saving the curve, you have to re-enter RTA mode manually.
[BYPASS] and [ALL] work the same in RTA mode as they do in Program mode. When you hit one of these buttons, the Bypass status of the channels will change as described on pages 28 and 29.
If you were in Program mode when you entered RTA mode, turning the [VALUE] encoder will change the program number and the DEQ830 will exit RTA mode. If you were in Edit mode when you entered RTA mode, the encoder will edit the bands you had selected.
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.
Held peaks may be reset at any time by pressing the [RTA] button and holding it for about a second.

Displayed Setting

No Hold 1 Second 2 Seconds Infinite

Description

Peaks are not held. Peaks are held for one second. Peaks are held for two seconds. Peaks are held until cleared, or until you exit RTA mode.
If you want to reset the peaks while they are being held, press and hold the [RTA] button for about a second.
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. An alternate selection method is to press and hold [UTILITY] and turn the [VALUE] encoder in either direction. The following table shows the functions that are available in Utility mode:

Function

Master Level Release Edit Group Edit Time Out MIDI Channel MIDI Program Chg MIDI Out/Thru Select Sample Rate Select Force Analog Input Fast Program Select Peak Mode Sys-Ex Transmit
To return to Program mode from Utility mode, press the [PROGRAM] button.
In Utility mode, the Band Gain LEDs will spell out an abbreviated form of the name of each function, as shown in the Displayed column in the table on this page.

Displayed

If you are likely to edit only one or two bands at a time when constructing a new curve, set the Release Edit Group function to On. This will enable you to move more quickly across the audio spectrum.
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. We have included this feature so the DEQ830 can mold itself as seamlessly as possible into your working style. If you prefer not to have the unit continue reminding you it is still in Edit mode by blinking its LEDs (vying for your attention, as it were, with the VU meters on your mixer), then Edit Time Out is a feature you will appreciate. On the other hand, if you prefer to have the DEQ830 remain in Edit mode so you will not lose your chosen Edit Group when the unit returns to Program mode, you may want keep the Edit Time Out function off. The default setting for this function is "Off"; to enable it turn the [VALUE] encoder. MIDI Channel (ALL, 1-16) The setting for this function determines which MIDI channel the DEQ830 will use to send and receive program changes. The ALL setting means program changes will be received regardless of which channel they are on. When ALL is selected, program changes will be sent only on channel 1. Use the [VALUE] encoder to select the desired setting. MIDI Program Change (On/Off) This function determines whether the DEQ830 responds to MIDI Program Change messages. The default setting for the MIDI Program Change function is On. If you want the DEQ830 not to respond to program changes, use the [VALUE] encoder to change it to Off. MIDI Out/Thru Select (Out/Thru) Sometimes it is necessary to daisy-chain MIDI devices so the MIDI data from one unit will be passed through one or more other pieces of MIDI gear until it is able to reach the last unit in the chain. The DEQ830 will allow you to do that; just toggle this functions setting from Out to Thru (displayed as thr). The setting on this page will not affect whether or not the DEQ830 will send its memory out the MIDI Out jack. When that

Warning! Sending a sys-ex bank into the DEQ830 will overwrite the internal memory. Make sure you have backed up internal memory before you load in a new set of programs and curves.
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 its 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. In this mode the DEQ830 automatically cycles through the first 25 programs at a rate of 1 per second. To begin the pyrotechnics, first make sure you are in Program mode. Once you are, simultaneously press the [UTILITY] button and the [CHANNEL SELECT] button for Channel 6. To help prevent an accidental exit from Demonstration mode, only a few controls are active in this mode. The [MONITOR SELECT], [BYPASS] and [BYPASS ALL] buttons work the same way they do in Program mode (audio is bypassed by default). The [CHANNEL SELECT] buttons can be used to switch channels. To exit Demonstration mode, press the [PROGRAM] button.

Lock mode

To access Lock mode, first you must turn off the DEQ830. Then turn the unit back on, wait until you see the letters DEQ830 in the display, and then hold down the [UTILITY] button. After a couple of seconds you will see the word "Lock" appear in large letters above the [BAND SELECT] buttons. This mode allows you to do one simple thinglock the DEQ830s controls. To do this, use the [VALUE] encoder to select On for the Lock function. Default is Off, of course. This function enables you to choose a particular program as the only one that can be selected once the DEQ830 is powered on. After this has been done, pressing any button besides the [POWER] button will cause the Numerical LED Display to show Lo for locked. This is handy for environments in which the DEQ830 is used for tuning a room, for example, or whenever you don't want someone calling up a different program, editing the current program, and/or storing a different program on top of the one you have created for a particular application. It's simple to restore the DEQ830 to full functionality (i.e., unlock it). Just turn the unit off and power it up in Lock mode again (turn the unit on and then hold the [UTILITY] button). Then use the encoder to turn this feature off. The next time you power up the DEQ830, it will operate normally.

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. As you will see illustrated in the charts in this section, the Constant Q method allows for a higher degree of control over the sound being processed because of its significantly greater accuracy. Before we go any further, its time for some definitions: Q Variable Q The range of frequencies affected by a band A process in which the range of frequencies affected by a band changes as the amount of gain is cut/boosted A process in which the range of frequencies affected by a band stays the same as the amount of gain is cut/boosted

Constant Q

It may help to define these terms visually as well. In the following illustration, we see the three basic terms that govern the operation of a single band. The vertical bar of the graph represents decibels of cut/boost, and the horizontal bar represents frequency in Hz. The dotted line leading to the center of the curve indicates the frequency at which this band is set. You can see that in this example, Q covers a range of frequencies from about 200 Hz to about 5 KHz.
In the next illustration, the difference between a narrow Q and a wide Q is seen:
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. Constant Q In contrast, a Constant Q equalizer has a more consistent range of frequencies under its control throughout its cut/boost range, as illustrated below:
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. They have settings of + 6 dB, 0 dB, and + 6 dB, respectively:
You can see how the 0 dB setting on the Variable Q equalizer merely serves to round off the top of the curve; in actuality, this translates into a boost in the range of frequencies under that band's control. You would have to cut the gain on that band significantly to reduce the unintended consequences of boosting the other two frequency ranges. The Constant Q equalizer, on the other hand, has more precise control over each of the frequency bands. As you can see in this example, the effect on the center band is significantly lower:

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. The corresponding illustration for the Constant Q equalizer speaks for itself:
We offer this information regarding the differences between Constant Q and Variable Q equalizers not as an attempt to persuade the world to reject Variable Q equalizers out of hand; in some applications either would do the job nicely. But when a greater degree of control over the program material is needed, a Constant Q equalizer like the DEQ830 offers a significant advantage.

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, its absurd to suggest EQ settings without knowing what the source sounds like. EQ is a tool thats used to change the timbre of a sound, and its impossible to suggest an EQ setting that, for example, will make all guitars sound better. So the goal of this section is to give you some ideas for using EQ on your own tracks.

General EQ tips

Rock Kick Drum
A rock and roll kick drum is usually EQd quite a bit to make it sound the way it does on the radio. Usually an engineer will choose to cut some of the woofy low-midrange, while boosting the highend "slap" and maybe even some of the lows. Here is a setting to try on a close-miked kick drum: Select all frequencies below 80Hz and boost 3dB Cut 500Hz by 8dB Boost all frequencies above 5kHz by 4dB You may also want to apply some compression and gating with the Alesis CLX-440.

Vocal Air

A popular effect on vocals is to boost the high frequencies to add "air" to the vocal. This is an especially popular effect on ballads sung by R&B divas. This effect is achieved by boosting the high frequencies: Boost 16 kHz by 6dB Boost 20 kHz by 6dB

Tape Hiss Removal

If a recording has a lot of tape hiss, such as one transferred from cassette, you can usually get rid of it by dropping the high frequencies a bit: Select all frequencies from 8kHz up and cut them by 6dB Adjust the gain of different bands to compromise between keeping the high end of the recording and eliminating tape hiss.

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 thats feeding back. The following is best to try when the band and audience are not present: 1. Insert the EQ between the mixers monitor output and the monitor amplifier. 2. Slowly and carefully raise the monitor level to the point of feedback. Notice that it always feeds back at the same frequency unless the mic is moved a lot. As soon as you hear feedback, turn the monitor level down, but not off. 3. Select a band that is near where you think the feedback is occurring. For example, if youre getting high-frequency feedback, try 6.3 kHz. 4. Slowly raise the 6.3 kHz Band Gain level while listening for feedback. If you hear feedback, cut that frequency because you guessed right. 5. If you dont hear feedback, return that band to 0 and repeat this procedure with another frequency band. Once you hear feedback, cut that frequency. If you dont hear feedback at any frequency using this method, try boosting the monitor level a little more.
This procedure can be an effective tool in isolating and eliminating feedback in the main or house system as well.

Filtering effects

The answering machine
A popular vocal effect is to filter the voice to a limited frequency range. This telephone effect can be used on any instrument or mix. Heres how to get that sound on the DEQ830: 1. Press all of the [BAND SELECT] buttons in the ranges from 25 Hz to 630 Hz and from 6.3 kHz to 20 kHz on the channel you are using. Or you can hold down a [BAND SELECT] button and turn the [VALUE] encoder to select these frequency ranges. 2. Use the [VALUE] encoder to reduce all of these frequencies until their LEDs are at -12 dB. 3. Select all of the unedited frequencies and boost them as high as you can without clipping the signal. 4. Be sure to toggle the [BYPASS] button to compare the result with the original.

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. When youre done, look at the LEDs on the DEQ830 and remember the comb analogy. The bands set to +6 dB are the teeth of the comb, and those set to 12 dB are the spaces between the teeth. 2. For an even more interesting effect, unlink the first channel from the channel carrying the other side of the stereo spectrum and create the exact opposite settings. In other words, take the odd bands on the second channel to +6 dB this time and the even bands to 12 dB. Be sure to toggle the [BYPASS] and [LINK] status of each channel to get an idea of what is being done to the signal as it passes through the DEQ830. 3. Experiment with different sized "teeth" and "spaces." Put two adjacent frequencies down and the next one up, repeating the pattern. Try "broken" teeth (i.e., boosting some frequencies more than others)! Adjust which frequencies to emphasize/deemphasize to suit the incoming audio.

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. 7-51-0138-C 05/09/2003

PRODUCT OVERVIEW 2008

www.alesis.com

DEQ830

DEQ830 8-Channel Digital Graphic EQ
30 bands of extremely graphic EQ. It wouldnt be a stretch to call Alesis The Graphic EQ Company. Our MEQ230 is a standard in sound installations and studios, and the DEQ series now carries the torch with a groundbreaking approach to digital graphic EQs for every application and budget thats taking engineers by storm. The DEQ830 is the worlds most affordable 8-channel 1/3-octave digital graphic EQ. Though it fits in a compact one-space rack, we didnt skimp on connections or features. Sonic performance is superb, with 1/4 TRS balanced and ADAT Optical I/O. Change any of 30 bands on eight discrete channels with the press of a button. Get instant, sliderstyle visual feedback rather than squinting at a tiny LCD. And store your changes in 100 user programs, with 50 curve templates to get you started in any room. From tweaking project studio acoustics to tuning a concert hall to balancing a mix, Alesis graphic EQs give you more features and better audio performance than any units in their price range. Music by you. Graphic design by Alesis.

FEATURES:

>> 8 independent 1/3-octave digital graphic equalizers >> Enhanced 24-bit sound quality, 28-bit internal processing >> 8 channels of balanced 1/4 (+4/10 switchable) inputs and outputs, 8 channels of ADAT Optical in and out, MIDI in and out >> At-a-glance display lets you quickly check settings for each band and channel. Locking feature prevents unwanted changes >> 100 user programs, 50 curve templates for rapid setup >> Independent 10-segment level LEDs for each channel >> Bypass, compare, and channel A-B link controls >> 1U rackmount with internal power supply

Tech Specs:

>> Analog or Digital: Digital >> Programmable: Yes >> Type/Bandwidth: Graphic >> # of Channels/# of Bands: 8/30 >> Frequency Range (parametric, kHz): 120 Hz-20 kHz >> Constant Q: Yes >> Filter Type (HP, LP, etc.): HP; LP >> Analog I/O #/Type: (8) 1/4 TRS >> Digital I/O #/Type: (8) ADAT optical >> Maximum Boost/Cut: 12 dB >> Hard Bypass: yes >> Dynamic Range (dB): >97 dB
All information is preliminary and subject to change.
P: [401] 658.5760 // F: [401] 658.3640