How to Use This Manual

This manual is divided into the following sections describing the various functions of and applications for the DEQ230. 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 DEQ230 right away. It's a short guide to the essential elements of hooking it up and using it for the first time. Chapter 2: Connections. This section gives detailed instructions for connecting the DEQ230 to a variety of typical audio systems. Chapter 3: Basics of Equalization. This section explains what an equalizer does and explains the function of each of the controls. Chapter 4: Applications. Skip to this section for tips on using the DEQ230 in a variety of settings. Chapter 5: Program Charts. Here you will find the names for all 60 Factory Programs, with a brief description of each and a small graphic representation of the front panel settings. Chapter 6: Troubleshooting. Near the end of the manual you will find troubleshooting tips and a complete list of the DEQ230s specifications.
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 DEQ230. Helpful tips and advice are highlighted in a shaded box like this.
The names of specific buttons on the DEQ230 are printed in a bold font and bracketed: i.e., the [BYPASS] button.
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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.
Please follow these precautions when using this product:
1. 2. 3. 4. 5. 6. 7. 8. 9. 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. Install in accordance with the manufacturer's instructions. Do not install near any heat sources such as radiators, heat registers, stoves, or other apparatus (including amplifiers) that produce heat. 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. Protect the power cord from being walked on or pinched, particularly at plugs, convenience receptacles, and the point where they exit from the apparatus. Use only attachments or accessories specified by the manufacturer. Continued next page

10. 11.

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.
Instructions de Scurit Importantes (French) Symboles utiliss dans ce produit
Ce symbole alrte lutilisateur quil existe des instructions de fonctionnement et de maintenance dans la documentation jointe avec ce produit.
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Ce symbole prvient l'utilisateur de la prsence de tensions sur les raccordements de sorties, reprsentant un risque d'lectrocution.
Veuillez suivre ces prcautions lors de lutilisation de lappareil:
1. 2. 3. 4. 5. 6. 7. 8. 9. Lisez ces instructions. Gardez ces instructions. Tenez compte de tous les avertissements. Suivez toutes les instructions. Nutilisez pas cet allareil proximit de leau. Ne nettoyez quavec un chiffon humide. Il est potentiellement dangereux d'utiliser des pulvrisateurs ou nettoyants liquides sur cet appareil. Installez selon les recommandations du constructeur. Ne pas installer proximil de sources de chaleur comme radiateurs, cuisinire ou autre appareils (dont les amplificateurs) produisant de la chaleur. Ne pas enlever la prise de terre du cordon secteur. Une prise murale avec terre deux broches et une troisirme relie la terre. Cette dernire est prsente pour votre scurit. Si le cordon secteur ne rentre pas dans la prise de courant, demandez un lectricien qualifi de remplacer la prise. Evitez de marcher sur le cordon secteur ou de le pincer, en particulier au niveau de la prise, et aux endroits o il sor de lappareil. Nutilisez que des accessoires spcifis par le constructeur. Suite de la page suivante

Remember: if one or both of the red LEDs light up, that means the signal is clipping. To prevent this, reduce the level being sent to the proper channel.
Step 3: Try some filtering effects

The answering machine

A popular vocal effect is to filter the voice to a limited frequency range. This telephone effect is also called futzing, and can be used on any instrument or mix. Heres how to get that sound on the DEQ230: 1. Follow the instructions for items 1 and 2 from Step 2. 2. 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. 3. Use the [DOWN] BUTTON to reduce all of these frequencies until their LEDs are at -12 dB. 4. Select all of the unedited frequencies and boost them as high as you can without clipping the signal.
If the Numeric LED Display shows Li when you press [BAND SELECT] buttons on Channel B, it means the channels are linked. Either make the edits on Channel A, or return to Program mode and press [LINK/EXIT] to unlink the channels.
5. 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 DEQ230: 1. Follow the instructions for items 1 and 2 from Step 2. 2. Starting from the far left of Channel A, 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 DEQ230 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. 3. For an even more interesting effect, press the [LINK/EXIT] button to unlink the bands on Channel B from Channel A and create the exact opposite settings. In other words, take the odd bands on Channel B to +6 dB this time and the even bands to 12 dB. Be sure to toggle the [BYPASS] and [LINK/EXIT] buttons to get an idea of what is being done to the signal as it passes through the DEQ230. 4. 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. You'll be glad you have 30 User program locations for saving the results (see below).
Note: depending on the incoming audio, it may be necessary to reduce the gain on some bands to prevent clipping.
There are preset programs similar to the ones used in these examples. You may find it interesting to compare the results of the different settings used in program 08 ("Comb filter - 125 Hz") and program 14 ("Telephone").

[BYPASS]

When this button is first pressed, a red LED will light. This means the DEQ230 is in Bypass mode. As long as this LED is lit, incoming audio will pass through the unit without being affected by the DEQ230. This is useful for comparing the "equalized" signal with 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 mode hides the effect the EQ and Channel Level controls have on the audio. However, the Master Level function from Setup mode is unaffected by the [BYPASS] button. For more information about the relationship between Channel Level and Master Level, see page 42.

[STORE]

Once you have made an edit you would like to keep, press this button to enter Store mode. From there you can decide which of the 30 User locations will become the new home for the edited Program. You can also copy the settings from Channel A to Channel B as you store a program. For more information on this function, see page 36.

[LINK/EXIT]

This button serves a dual purpose: 1. While in Program mode, pressing this button will cause the settings for Channel B to "mirror" the settings for Channel A. Any further edits you make to a band on Channel A will also happen to that same band on Channel B. This is useful for quickly setting up a program without having to make independent adjustments for each channel. 2. If youre in the middle of some other activity, such as editing or storing, pressing this button will allow you to "exit" to Program mode.
It is possible to copy the settings from Channel A to Channel B during the Store process so they are not merely mirrored. See page 36 for further details.
Description of the Basic Modes

Program Mode

When this manual refers to Program mode, we mean the very top level of functionality of the DEQ230. Program mode is where you are when it is possible to use the [DOWN/UP] buttons to select between the different programs that reside in the unit. In this mode, you have access to the 30 Preset programs and 30 User programs. A Program consists of all of the settings on the front panel, with the exception of the status of the [BYPASS] button. The things stored in memory and recalled when you select a program are: The gain settings of all 30 bands for both channel A and channel B The status of the [LINK/EXIT] button The gain settings for all 30 bands of channel B, even if the Link function is active. They are merely "hidden" by the Link function. The individual Channel Level settings for channels A and B

Youll find a description of Channel Level mode further down on this page. For a description of the Master Level function, turn to page 42.

Audition mode

Audition mode allows you to choose specific programs and place them into the Audition List. From there you can more easily audition only those programs you want to hear for a particular audio source and "jump over" the ones you do not. To learn how to use this mode, see page 38.

Channel Level mode

If you are running two different instruments into channels A and B, you may be experiencing drastically different signal levels in each Channel. Channel Level mode allows you to adjust the output of channels A and B 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 DEQ230 to clip, Channel Level mode allows you to adjust the output of channels A and B simultaneously. Unlike the Master Level function in Setup mode, the settings for Channel Level mode are stored with each program. To learn how to use this mode, see page 40.
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 DEQ230 has 60 programs in all: 30 Preset programs and 30 User programs. The Preset programs are the ones numbered 00-29, while the User programs are numbered 3059. You can use the Preset programs as starting points for your own programs, but you cannot store your creations back on top of a Preset program. That's what the User programs are for. Navigation in Program mode is a breeze. First, if you're not in Program mode, get there by pressing the [LINK/EXIT] button. The large LED readout will show you the number of the current program. All you have to do to call up a new Program is press one of the [DOWN/UP] buttons. If you hold down one of the [DOWN/UP] buttons for a few seconds, the DEQ230 will begin to race through the programs. That's one way to get from Program 10 to Program 40 more quickly, for example. You'll also notice that it doesn't matter whether you go up or down; you can get from Program 10 to Program 40 going either direction. But there's a way to get around Program mode even more quickly. If you press and hold the [UP] button while you press the [DOWN] button, the DEQ230 will jump to Program 00. If you keep pressing the [DOWN] button, the DEQ230 will jump backward through the programs in increments of 10 (50, 40, 30, etc.). Likewise, if you press and hold the [DOWN] button while you press the [UP] button, the DEQ230 will jump to Program 00. And if you keep pressing the [UP] button, the DEQ230 will jump forward through the programs in increments of 10 (10, 20, 30, etc.). Once you get the hang of those two methods of navigation, you can reach any program in the unit's memory in two seconds or less.

In Multiple Band Edit mode, pressing the [DOWN/UP] buttons at the same time will reset the Relative Gain Display to 0. This resets the bands within the Edit Group back to their original values. From this point you can change the Relative Gain of the Edit Group in 2 dB increments by holding one of the [DOWN/UP] buttons and pressing the other one repeatedly.
For maximum preservation of fidelity of the input signal, the largest number of bands in a channel should be set to 0 dB. For example, if you have more than half of your bands set to some cut amount and the majority of those cut frequencies are at -4 dB, then select all bands and compensate by +4 dB.
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." It was, in the sense that the DEQ230 keeps track of the proportional values of the bands, even if they exceed the +/-12 dB limit of gain change for a frequency. But the audible audio gain is limited to +/-12 dB. The reason the DEQ230 keeps track of the gain relationship between the bands in the Edit Group is simple. It's so you can change your mind, pull them back down to values within the +/12 dB limit, and still have them be the same distance apart! For example: let's say you decided these frequencies have been boosted too much, and you cut them by 12 dB. At this point the Relative Gain display would read "12," with band one's Gain LED at +12 dB and band two's Gain LED at 0 dB (as in fig. 1). So far you haven't really reduced the gain of the first band, because it's still at +12 dB. You still want to bring it down a bit, so you take both frequencies down another 3 dB. So now the Relative Gain display would read "9," with band one's Gain value at +9 dB and
Remember, pressing the [DOWN/UP] buttons at the same time will reset the Relative Gain Display to 0. From this point you can change the Relative Gain of the Edit Group in 2 dB increments by holding one of the [DOWN/UP] buttons and pressing the other one repeatedly. This can be a real time-saver if you want to get from a Relative Gain value of +24 to a value of 24!
band two's Gain value at -3 dB. And now you can see that the gain relationship between the two bands was preserved; they're still 12 dB apart. One important note, though; Proportional Gain Memory is only temporary. If you have 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. This is because the DEQ230 takes into account the gain setting of all of the bands when an Edit Group is formed. If the highest gain setting of any band in the Edit Group is + 6 dB, then from there down to -12 dB is only 18 dB. So this is the largest number you will see in the Relative Gain display if you run the relative gain value all the way down (see fig. 3 and 4).

Channel Copy

You can use the Link function while editing to help set up identical curves on both channels. But at some point the curves may need to diverge slightly (or significantly). Rather than unlinking the channels and starting all over again on Channel B, we have included a handy feature called Channel Copy as a subset of Store mode. The Channel Copy feature is a real time-saver. It will allow the settings from Channel A to be stored over whatever settings are in Channel B, so that after the completion of the Store process there will be no difference between the settings of Channels A and B for that program. Then you can begin to diversify the settings of the channels to match the needs of the incoming audio. The process is simple, but it is subtly different from the normal Store procedure. Pay close attention to the following steps: 1. 2. 3. 4. 5. 6. 7. Before storing the program, unlink the channels. That way youll be able to begin editing Channels A and B independently as soon as you complete step 7. Press and hold the [STORE] button to enter Store mode. The Numeric LED Display will begin to flash. While holding the [STORE] button, press the [LINK/EXIT] button. This will cause the Link LED to begin flashing also. Release both buttons. Select the location for the new program using the methods described on the previous page. To abort the Store procedure, press the [LINK/EXIT] button. The settings for Channel A will not have been copied over to Channel B. To store the program, press the [STORE] button a second time. The settings for Channel A will have been duplicated on Channel B. To confirm this, toggle the [LINK/EXIT] button. You should see no difference between the settings of the channels. Even the Channel Level settings of Channel B should match that of Channel A.
Basic operation: Audition mode
No doubt there will be times when you want to switch back and forth between different programs to determine which one is best suited for the audio source. But as easy as it is to navigate between the DEQ230's programs in Program mode, it's still difficult to focus on what's happening to the audio when you're making sure you land on the right program. Audition mode provides the solution. It allows you to specify any of the 60 programs within the DEQ230 as members of the Audition List. This is like a series of bookmarks, allowing you to jump over programs that are not intended for a particular audio source and only call up the ones that are. To enter Audition mode, first be sure the DEQ230 is in Program mode. After that, press and hold the [LINK/EXIT] button and then press the [DOWN] button. You will see four more LEDs light up over one of the [BAND SELECT] buttons, in addition to the Band Gain LEDs that were already lit for the current program. These four LEDs indicate that the [BAND SELECT] button beneath them now represents the active program in the Audition List. You will also see the number of the active program in the Numeric LED Display. As you know, the DEQ230 has 60 programs. Conveniently, it also has 60 [BAND SELECT] buttons. So in Audition mode the [BAND SELECT] buttons represent a "map" of the Preset and User programs, and are used to select the programs that will be auditioned. For example, if you entered Audition mode while you were on Preset program 04, then the stack of lit LEDs would be above the 63 Hz band on Channel A. If you want to toggle between that program and Preset program 10, count six [BAND SELECT] buttons to the right and press the 250 Hz button. You will notice that now there are four LEDs lit above the 250 Hz [BAND SELECT] button and only two LEDs lit above the 63 Hz band. As you recall, the four LEDs indicate which of the programs is active. The presence of two lit LEDs indicates that a program is part of the Audition List, but is not currently the active program. You may add as many programs as you like to the Audition List. If you no longer want a given program to be part of the Audition List, simply press its [BAND SELECT] button again briefly. Its LED will turn off, indicating that this program will be skipped over the next time you cycle through the Audition List. To exit Audition mode, press the [LINK/EXIT] button again, or deselect all programs from the Audition List.

Be sure to store any edits you want to keep prior to entering Audition mode. The Audition list only uses Preset programs or programs that have been stored to the User locations.
The [BYPASS] button is also available in Audition mode. You can use it to audition the original signal manually, or you can use program 00 Flat in the Audition list to automate theDEQ230s return to the unprocessed audio signal.
Remember, the very first program is program 00. So if you want to include program 01 in the Audition list, you will need to select the second [BAND SELECT] button from the left. This is because program 01 is the second program in the DEQ230s memory.
If you cant remember what factory curves correspond to each program number, refer to the Program Charts in Chapter 5.

Audition Automation

There are two ways to toggle between the programs in the Audition List: manually and automatically. The DEQ230 defaults to the automatic method, which we call Audition Automation. Once you have finished adding programs to the Audition List, the DEQ230 begins cycling through the programs from left to right. It will start with the currently active program, pause for several seconds, and move on to the next. When it reaches the last program in the Audition List, it will start over again from the first one on the left. Remember that the stack of four LEDs will indicate which program is currently the active one. Also note that you can edit the Audition List by adding or removing programs during the Audition Automation cycle. Its possible to shorten or lengthen the amount of time spent on each program in the Audition List during Audition Automation. Use the [DOWN/UP] buttons for this purpose. The time range is from 1-25 seconds in increments of one second. You will see the value briefly in the Numeric LED Display as you change it, and then the display will resume showing the number of the current program in the Audition List. The Audition Automation time value you select will be remembered even after turning the DEQ230 off and on again. Audition Automation override If you want to hear a certain program again without having to wait for the DEQ230 to cycle through the entire Audition List, simply press and hold that program's [BAND SELECT] button. This will call up that program immediately. And as long as you hold down that [BAND SELECT] button, the DEQ230 will suspend the Audition Automation cycle and stay on that program. Once you release the button, the next program in the Audition List will be called up and the cycle will continue from there.

When changing the time value for the Audition Automation, keep in mind that the choices wrap; i.e., you can reach a value of 25 from a value of 01 with a single press of the [DOWN] button.

Manual Audition

If you prefer to call up each program in the Audition List at your own pace, then you must turn off the Audition Automation feature. To do this, you will need to enter Setup mode and toggle the setting for the AUD AUTO function. For information on how to do this, see page 43. Once you have turned off the Audition Automation feature, navigation through the Audition List is handled by the [DOWN/UP] buttons. Pressing the [DOWN] button will move you leftward through the Audition List, and pressing the [UP] button will move you rightward through the list. If you have a lot of programs in the Audition List, hold down one of those buttons and after a couple of seconds the DEQ230 will begin to scroll through them more quickly.
If you want to audition programs in a specific order, save them to locations in the User area (programs 30-59) in the order youd like to hear them. Then select them in Audition mode.
Basic operation: Channel Level mode
Channel Level mode allows you to adjust the output level of channels A and B independently or simultaneously. Use this feature to compensate for a reduction or increase of signal level due to the equalization curve you have selected. To enter this mode you must start from Program mode. Once you are there, you can enter Channel Level mode in one of two ways: On Channel A, press and hold the 16 kHz button and then press the 20 kHz button, or vice versa On Channel B, press and hold the 25 Hz button and then press the 31.5 Hz button, or vice versa. (This option only works when the channels are not linked.) Note: If you press only one Band Gain button, you won't enter Channel Level mode--you may have entered Band Edit mode by mistake.
Once you are in Channel Level mode, you must press both of the appropriate Band Gain buttons on one or the other side of the Numeric LED Display in order to select or deselect one of the channels. If you press only one Band Gain button, the channel selection will not change.

Once the DEQ230 is in Channel Level mode, you will see the Band Gain LEDs go completely dark except for the ones over the buttons mentioned in the two steps above. From this point onward, Channel Level mode operates exactly like Band Edit mode: the settings for Release Edit Group and Edit Time Out are in effect; if you select both channels A and B for editing, you have selected an Edit Group; the Relative Gain Display and Proportional Gain Memory will govern the gain adjustments made to the Edit Group. The only real difference between the way this mode and Edit mode operate is in the amount of boost that is allowed to occur in Channel Level mode. The DEQ230 will allow each channel to be boosted up to +6 dB, with an allowable cut range of -12 dB. If you want another 6 dB of gain (for a total of 12 dB), you will find that in the Master Level function in Setup mode. But remember, the settings for Channel Level mode are stored with each program. The settings for the Master Level function are not. To exit Channel Level mode and return to Program mode, deselect both channels or press the [LINK/EXIT] button.
For information on selecting an Edit Group, see page 32. For information on the Release Edit Group function, see page 42. For information on the Edit Time Out feature, see page 43. For information on the Relative Gain Display, see page 32. For information on Proportional Gain Memory, see page 32.
The "Hidden" Modes
There are several sub-levels of operation that can be accessed from Program mode by pressing different buttons:

Demonstration mode

Sometimes its fun to have a lot of little lights flashing from the stage or in the studio. The DEQ230 has a special key combination that will activate a light show for the entertainment of your clients, audience, or children. To begin the pyrotechnics, first make sure you are in Program mode. Once you are, hold down the [LINK/EXIT] button and press the [UP] button. To exit Demonstration mode, press the [LINK/EXIT] button.
Being in Demonstration mode is something like being in Audition mode; the DEQ230 will cycle automatically through all 60 programs one after the other. The main difference is that while in Demonstration mode, the audio signal is bypassed.

Setup mode

This is where you will find some of the features that govern the way the DEQ230 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. And since they make such a big difference in how the unit works, they have been "tucked away" so they wont be altered accidentally. To access Setup mode, first you must turn off the DEQ230. Then turn the unit back on, wait until you see the letters DEQ230 in the display, and then hold down the [STORE] button. After a couple of seconds you will see the word "SETUP" appear in large letters above Channel As [BAND SELECT] buttons. Then the LEDs over Channel A will read "M. LVL," and the LEDs over Channel B will read "+00." The first five [BAND SELECT] buttons of Channel A are used to select between the different functions in Setup mode. They are:

Instruments usually sound better when you cut the problem frequencies instead of boosting the frequencies you want to feature.
Constant Q vs. Variable Q
What makes the DEQ230 unique?
At their inception, graphic equalizers relied solely on a form of equalization known as "Variable Q." The DEQ230, 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, it's time for some definitions: 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

Variable Q

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 Now we're ready for a visual definition of the term 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:

Rap Drums Hype

If you've got a drum machine or drum mix that calls for woof and hot treble, send it through this curve.

Sizzle Cymbals

Reduce any live drum bleed-through and emphasize the cymbals' place at the high end of the mix.

Cardboard Tube

Remember when you were a kid and you had a friend speak to you through a cardboard tube?

Bathtub

Do you like the sound of singing in the shower?

Mild Comb

This is a variant on the comb-filter effect that is not as drastic as some of the other comb filter presets.

Resonance (125Hz)

This setting is meant to emphasize 125Hz and all its harmonics such as 250Hz, 500Hz, 1kHz, 2kHz, etc.
45 11kHz Sample Rate If you want to digitize your signal at a very low sample rate like 11kHz for effect, bandlimiting it to half the sample rate (approximately 5kHz) will help you avoid some nasty sounding artifacts of the sampling process.

Next Door Neighbor

This is what it sounds like when there's a party going on next door.
Note for programs 47-49 These three following programs are for DJ's to squash the response of the music in order to create a temporary effect or to announce over.
47 High DJ Isolation See note for programs 47-49

Mid DJ Isolation

See note for programs 47-49

Low DJ Isolation

This response boosts the frequencies that most mix or live sound engineers cut because these are the frequencies that are hollow and honking.
51 Proximity Effect This curve is meant to mimic the physics phenomenon that the closer your ear (or a microphone) gets to a sound source, the more the bass is emphasized.

Presence

This curve gives the signal a little more life when you want to get the listener's attention.

Distance

Sometimes you want the signal to not be so much of an attention grabber.

Combfilter Combo

This is just whacky. This is what happens when you send a stereo signal through two different comb filter curves--Channel A using a resonant base of 125Hz while Channel B uses a resonant base of 50Hz.
Store one of your programs here.

6 Troubleshooting

Restoring the Factory Programs & Defaults
There is a power-up button combination that will restore the DEQ230's User programs to the factory default programs. This same combination of buttons will reset all of the Setup functions to their default values. This procedure is called "reinitializing." To reinitialize the DEQ230, follow these steps: 1. Make sure you really want to erase every program you have stored. That is what reinitializing the unit does. 2. If you haven't already, turn off the DEQ230. 3. Turn the unit on while pressing the [DOWN/UP] buttons. 4. When you see the word "RESET" in large letters over the [BAND SELECT] buttons, you may let go of the [DOWN/UP] buttons. After a couple of seconds, the DEQ230 will return to Program mode.

WARNING! Following the procedures in this section will ERASE ALL OF YOUR USER PROGRAMS and replace them with the User programs that shipped with the DEQ230. Please be certain this is what you want to do before going through these steps.
Line Conditioners and Protectors
Although the DEQ230 is designed to tolerate typical voltage variations, in todays 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 three main ways to protect against this, listed in ascending order of cost and complexity: Line spike/surge protectors. Relatively inexpensive, these are designed to protect against strong surges and spikes, acting somewhat like fuses in that they need to be replaced if theyve been hit by an extremely strong spike. Line filters. These generally combine spike/surge protection with filters that remove some line noise (dimmer hash, transients from other appliances, etc.). A good example is the Isobar series from Tripp Lite.

Care and Maintenance

Cleaning
Disconnect the AC power supply, then use a damp cloth to clean the DEQ230s metal and plastic surfaces. For heavy dirt, use a non-abrasive household cleaner such as Formula 409 or Fantastik. DO NOT SPRAY THE CLEANER DIRECTLY ONTO THE FRONT OF THE UNIT AS IT MAY DESTROY THE LUBRICANTS USED IN THE SWITCHES AND CONTROLS! Spray onto a cloth, and then use the cloth to clean the unit.
Do not spray cleaning solution of any sort onto the front panel of the DEQ230. If a cleaning becomes necessary, spray a recommended cleaning solution onto a cloth first, and use the cloth to clean the front panel.

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. (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.) Cant edit program, cant select new program. Numeric LED Display keeps flashing Li. DEQ230 is locked. Channel B is linked to Channel A. Solution Test with a known good input. Replace the cables. Check the connections and the level of the mixer or amp to which the DEQ230 is connected. Increase level from source into DEQ230. Boost channel levels of quiet program. Boost Master Level in Setup mode. Reduce input level at source. Reduce gain of problem bands within program. Reduce channel levels of that program. Reduce Master Level in Setup mode. Unlock DEQ230 in Setup mode. Refer to page 43. Edit Channel A Unlink the Channels to allow independent edits to Channel B. Unlock DEQ230 in Setup mode. Refer to page 43. Set Release Edit Group function to On in Setup mode. Turn on power first, then hold down [STORE] button to enter Setup mode. Turn on power first, then press [DOWN/UP] buttons to re-initialize.

DEQ230D only: 22. Real-time Analysis (RTA) mode for visual feedback of incoming audio signal, with selectable metering modes 23. S/PDIF input/output, auto-senses incoming digital audio 24. Clock selectable between 44.1k and 48k sampling rates 25. MIDI in/out for program changes and sys-ex storage 26. Balanced input/output (TRS) 27. +4/-10 operating level switch (rear panel) For full operating specifications, see page 75.

How to Use This Manual

This manual is divided into the following sections describing the various functions of and applications for the DEQ230. 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 DEQ230 right away. It's a short guide to the essential elements of hooking it up and using it for the first time. Chapter 2: Connections. This section gives detailed instructions for connecting the DEQ230 to a variety of typical audio systems. Chapter 3: Basics of Equalization. This section explains what an equalizer does and explains the function of each of the controls. Chapter 4: Applications. Skip to this section for tips on using the DEQ230 in a variety of settings. Chapter 5: Program Charts. Here you will find the names for all 60 Factory Programs, with a brief description of each and a small graphic representation of the front panel settings. Chapter 6: Troubleshooting. Near the end of the manual you will find troubleshooting tips and a complete list of the DEQ230s specifications.
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 DEQ230. Helpful tips and advice are highlighted in a shaded box like this.
The names of specific buttons on the DEQ230 are printed in a bold font and bracketed: i.e., the [BYPASS] button.
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Important Safety Instructions
Important Safety Instructions (English) Safety symbols used in this product

Installing in a Rack

The DEQ230 may be simply set on a table, or installed in a standard 19" audio equipment rack.
Thermal Considerations in Rack Mounting
The DEQ230 can be mounted in an equipment rack (occupying one rack space) or placed on a table or shelf. When you install it, keep in mind that heat is the greatest enemy of electronic equipment. Please observe the following: The DEQ230 is designed to perform properly over a range of ambient temperatures from 10 C to +40 C (50 F to 104 F), in up to 80% non-condensing humidity. These are not absolute limits, but Alesis cannot guarantee that the DEQ230 will meet its published specs or remain reliable if operated outside of these ranges. Always allow adequate ventilation behind the DEQ230. Do not seal any enclosure that holds this unit. It is not necessary to leave an empty rack space above or below the DEQ230. However, if your environment is unusually warm and not air conditioned, space between units will help the units run cooler.

Connections

AC Power Hookup
The DEQ230D has whats 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 A/C cable for the country in which you find yourself. Just plug the "female" end of the power cable into the DEQ230Ds POWER receptacle and the male end into a good quality, noise-free A/C power source. The DEQ230 will work with any standard line voltage from 100 to 240 volts as long as the appropriate detachable power supply adapter is used. The DEQ230 has been shipped with the suitable adapter for the line voltage in your area. Plug the "barrel" end of an approved power supply adapter into the DEQ230s POWER 9V AC jack and the transformer end into a good quality, noise-free AC power source of the proper rating.
To use the DEQ230 in another country:
Your DEQ230 was supplied with the correct power supply adapter for your country or local area. If you plan to travel with it to another country, obtain an Alesis AC power supply adapter compatible with the outlets used in the other country and use it in place of the supplied adapter. These can be obtained through your Alesis dealer or through the Alesis Parts department.
The DEQ230 is specifically designed to be powered by the power supply adapter we have included. Do not substitute any other type of power supply adapter. If a replacement is needed, one may be purchased from your Alesis dealer or from the Alesis Parts department.

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 DEQ230 as an effects insert device, you will need an insert cable (not included).
When connecting audio cables and/or turning power on and off, please make sure that your amplifiers are turned off or down to prevent damage to your speakers.
This cable splits the TRS insert jack into two unbalanced mono connectors. Usually, the tip is wired to the "Send" connector, which plugs into one INPUT of the equalizer, and the ring is wired to the "Return" connector, which plugs into the corresponding OUTPUT of the equalizer. However, the wiring of the insert jacks is different on some recording consoles, which means that the input/output relationship may be reversed. Check your mixers Reference Manual to be sure, or just try it both ways this wont damage the DEQ230.
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 DEQ230, 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 DEQ230 to one mono source. You can use this method to connect two mono sources or one stereo source to the DEQ230. You would need two insert cables to make both of these connections. Stereo connections Use two insert cables to connect the DEQ230 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 CHAN A INPUT and OUTPUT of the DEQ230. Use another insert cable to connect the right main insert to the CHAN B INPUT and OUTPUT of the DEQ230. You can also simply connect the balanced main outputs of the mixer to the inputs of the DEQ230, then connect the outputs of the equalizer to the inputs of your mixdown recorder, monitor system, etc.
Since the DEQ230 has two channels, A and B, you can connect two independent sources. For example, you could use channel A to EQ the rhythm guitar and channel B to EQ the bass guitar. Or use channel A on the kick drum and channel B for the snare drum.

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.

Basics of Equalization

Description of the Controls
There are thirty buttons side-by-side on each channel of the DEQ230. These are the [BAND SELECT] buttons. Above each button 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. Situated between the [BAND SELECT] buttons for Channel A and Channel B you will find three larger buttons. The one in the very middle is the [POWER] button. On either side of that are the [DOWN] and [UP] buttons, which are 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; more about this later.) The [DOWN/UP] buttons are also used to select programs in Program mode. Directly above these three buttons are three more buttons: the [BYPASS], [STORE], and [LINK/EXIT] buttons. Their functions are as follows:

[BYPASS]

When this button is first pressed, a red LED will light. This means the DEQ230 is in Bypass mode. As long as this LED is lit, incoming audio will pass through the unit without being affected by the DEQ230. This is useful for comparing the "equalized" signal with 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 mode hides the effect the EQ and Channel Level controls have on the audio. However, the Master Level function from Setup mode is unaffected by the [BYPASS] button. For more information about the relationship between Channel Level and Master Level, see page 45.

[STORE]

Once you have made an edit you would like to keep, press this button to enter Store mode. From there you can decide which of the 30 User locations will become the new home for the edited Program. You can also copy the settings from Channel A to Channel B as you store a program. For more information on this function, see page 38.

[LINK/EXIT]

This button serves a dual purpose: 1. While in Program mode, pressing this button will cause the settings for Channel B to "mirror" the settings for Channel A. Any further edits you make to a band on Channel A will also happen to that same band on Channel B. This is useful for quickly setting up a program without having to make independent adjustments for each channel. 2. If youre in the middle of some other activity, such as editing or storing, pressing this button will allow you to "exit" to Program mode.

Pressing the [STORE] button takes you into Store mode. From here you can decide which of the 30 User Programs will become the new location for the edited program. You may also instruct the DEQ230 to copy the settings from Channel A to Channel B during the Store process. For information on how to perform either of these procedures, see page 38.

Bypass mode

This mode is nearly as simple as it sounds: push the [BYPASS] button and the DEQ230 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. Here is a diagram that shows the relationship of each of the stages in the DEQ230s 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 45.

Audition mode

Audition mode allows you to choose specific programs and place them into the Audition List. From there you can more easily audition only those programs you want to hear for a particular audio source and "jump over" the ones you do not. To learn how to use this mode, see page 40.

Channel Level mode

If you are running two different instruments into channels A and B, you may be experiencing drastically different signal levels in each Channel. Channel Level mode can be used to adjust the output of channels A and B 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 DEQ230 to clip, Channel Level mode can be used to adjust the output of channels A and B simultaneously. Unlike the Master Level function in Setup mode, the settings for Channel Level mode are stored with each program. To learn how to use this mode, see page 42.
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 DEQ230 has 60 programs in all: 30 Preset programs and 30 User programs. The Preset programs are the ones numbered 00-29, while the User programs are numbered 3059. You can use the Preset programs as starting points for your own programs, but you cannot store your creations back on top of a Preset program. That's what the User programs are for. Navigation in Program mode is a breeze. First, if you're not in Program mode, get there by pressing the [LINK/EXIT] button. The large LED readout will show you the number of the current program. All you have to do to call up a new Program is press one of the [DOWN/UP] buttons. If you hold down one of the [DOWN/UP] buttons for a few seconds, the DEQ230 will begin to race through the programs. That's one way to get from Program 10 to Program 40 more quickly, for example. You'll also notice that it doesn't matter whether you go up or down; you can get from Program 10 to Program 40 going either direction. But there's a way to get around Program mode even more quickly. If you press and hold the [UP] button while you press the [DOWN] button, the DEQ230 will jump to Program 00. If you keep pressing the [DOWN] button, the DEQ230 will jump backward through the programs in increments of 10 (50, 40, 30, etc.). Likewise, if you press and hold the [DOWN] button while you press the [UP] button, the DEQ230 will jump to Program 00. And if you keep pressing the [UP] button, the DEQ230 will jump forward through the programs in increments of 10 (10, 20, 30, etc.). Once you get the hang of those two methods of navigation, you can reach any program in the unit's memory in two seconds or less.

In Multiple Band Edit mode, pressing the [DOWN/UP] buttons at the same time will reset the Relative Gain Display to 0. This resets the bands within the Edit Group back to their original values. From this point you can change the Relative Gain of the Edit Group in 2 dB increments by holding one of the [DOWN/UP] buttons and pressing the other one repeatedly.
For maximum preservation of fidelity of the input signal, the largest number of bands in a channel should be set to 0 dB. For example, if you have more than half of your bands set to some cut amount and the majority of those cut frequencies are at -4 dB, then select all bands and compensate by +4 dB.
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." It was, in the sense that the DEQ230 keeps track of the proportional values of the bands, even if they exceed the +/-12 dB limit of gain change for a frequency. But the audible audio gain is limited to +/-12 dB. The reason the DEQ230 keeps track of the gain relationship between the bands in the Edit Group is simple. It's so you can change your mind, pull them back down to values within the +/12 dB limit, and still have them be the same distance apart! For example: let's say you decided these frequencies have been boosted too much, and you cut them by 12 dB. At this point the Relative Gain display would read "12," with band one's Gain LED at +12 dB and band two's Gain LED at 0 dB (as in fig. 1). So far you haven't really reduced the gain of the first band, because it's still at +12 dB. You still want to bring it down a bit, so you take both frequencies down another 3 dB. So now the Relative Gain display would read "9," with band one's Gain value at +9 dB and band two's Gain value at -3 dB. And now you can see that the gain relationship between the two bands was preserved; they're still 12 dB apart.
Remember, pressing the [DOWN/UP] buttons at the same time will reset the Relative Gain Display to 0. From this point you can change the Relative Gain of the Edit Group in 2 dB increments by holding one of the [DOWN/UP] buttons and pressing the other one repeatedly. This can be a real time-saver if you want to get from a Relative Gain value of +24 to a value of 24!

Channel Copy

You can use the Link function while editing to help set up identical curves on both channels. But at some point the curves may need to diverge slightly (or significantly). Rather than unlinking the channels and starting all over again on Channel B, we have included a handy feature called Channel Copy as a subset of Store mode. The Channel Copy feature is a real time-saver. It will allow the settings from Channel A to be stored over whatever settings are in Channel B, so that after the completion of the Store process there will be no difference between the settings of Channels A and B for that program. Then you can begin to diversify the settings of the channels to match the needs of the incoming audio. The process is simple, but it is subtly different from the normal Store procedure. Pay close attention to the following steps: 1. 2. 3. 4. 5. 6. 7. Before storing the program, unlink the channels. That way youll be able to begin editing Channels A and B independently as soon as you complete step 7. Press and hold the [STORE] button to enter Store mode. The Numeric LED Display will begin to flash. While holding the [STORE] button, press the [LINK/EXIT] button. This will cause the Link LED to begin flashing also. Release both buttons. Select the location for the new program using the methods described on the previous page. To abort the Store procedure, press the [LINK/EXIT] button. The settings for Channel A will not have been copied over to Channel B. To store the program, press the [STORE] button a second time. The settings for Channel A will have been duplicated on Channel B. To confirm this, toggle the [LINK/EXIT] button. You should see no difference between the settings of the channels. Even the Channel Level settings of Channel B should match that of Channel A.
Basic operation: Audition mode
No doubt there will be times when you want to switch back and forth between different programs to determine which one is best suited for the audio source. But as easy as it is to navigate between the DEQ230's programs in Program mode, it's still difficult to focus on what's happening to the audio when you're making sure you land on the right program. Audition mode provides the solution. It allows you to specify any of the 60 programs within the DEQ230 as members of the Audition List. This is like a series of bookmarks, allowing you to jump over programs that are not intended for a particular audio source and only call up the ones that are. To enter Audition mode, first be sure the DEQ230 is in Program mode. After that, press and hold the [LINK/EXIT] button and then press the [DOWN] button. You will see four more LEDs light up over one of the [BAND SELECT] buttons, in addition to the Band Gain LEDs that were already lit for the current program. These four LEDs indicate that the [BAND SELECT] button beneath them now represents the active program in the Audition List. You will also see the number of the active program in the Numeric LED Display. As you know, the DEQ230 has 60 programs. Conveniently, it also has 60 [BAND SELECT] buttons. So in Audition mode the [BAND SELECT] buttons represent a "map" of the Preset and User programs, and are used to select the programs that will be auditioned. For example, if you entered Audition mode while you were on Preset program 04, then the stack of lit LEDs would be above the 63 Hz band on Channel A. If you want to toggle between that program and Preset program 10, count six [BAND SELECT] buttons to the right and press the 250 Hz button. You will notice that now there are four LEDs lit above the 250 Hz [BAND SELECT] button and only two LEDs lit above the 63 Hz band. As you recall, the four LEDs indicate which of the programs is active. The presence of two lit LEDs indicates that a program is part of the Audition List, but is not currently the active program. You may add as many programs as you like to the Audition List. If you no longer want a given program to be part of the Audition List, simply press its [BAND SELECT] button again briefly. Its LED will turn off, indicating that this program will be skipped over the next time you cycle through the Audition List. To exit Audition mode, press the [LINK/EXIT] button again, or deselect all programs from the Audition List.

Be sure to store any edits you want to keep prior to entering Audition mode. The Audition list only uses Preset programs or programs that have been stored to the User locations.
The [BYPASS] button is also available in Audition mode. You can use it to audition the original signal manually, or you can use program 00 Flat in the Audition list to automate theDEQ230s return to the unprocessed audio signal.
Remember, the very first program is program 00. So if you want to include program 01 in the Audition list, you will need to select the second [BAND SELECT] button from the left. This is because program 01 is the second program in the DEQ230s memory.
If you cant remember what factory curves correspond to each program number, refer to the Program Charts in Chapter 5.

Audition Automation

There are two ways to toggle between the programs in the Audition List: manually and automatically. The DEQ230 defaults to the automatic method, which we call Audition Automation. Once you have finished adding programs to the Audition List, the DEQ230 begins cycling through the programs from left to right. It will start with the currently active program, pause for several seconds, and move on to the next. When it reaches the last program in the Audition List, it will start over again from the first one on the left. Remember that the stack of four LEDs will indicate which program is currently the active one. Also note that you can edit the Audition List by adding or removing programs during the Audition Automation cycle. Its possible to shorten or lengthen the amount of time spent on each program in the Audition List during Audition Automation. Use the [DOWN/UP] buttons for this purpose. The time range is from 1-25 seconds in increments of one second. You will see the value briefly in the Numeric LED Display as you change it, and then the display will resume showing the number of the current program in the Audition List. The Audition Automation time value you select will be remembered even after turning the DEQ230 off and on again. Audition Automation override If you want to hear a certain program again without having to wait for the DEQ230 to cycle through the entire Audition List, simply press and hold that program's [BAND SELECT] button. This will call up that program immediately. And as long as you hold down that [BAND SELECT] button, the DEQ230 will suspend the Audition Automation cycle and stay on that program. Once you release the button, the next program in the Audition List will be called up and the cycle will continue from there.
When changing the time value for the Audition Automation, keep in mind that the choices wrap; i.e., you can reach a value of 25 from a value of 01 with a single press of the [DOWN] button.

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.
If the Release Edit Group feature is off, the next [BAND SELECT] button you press after you have changed the level of the Edit Group will simply add that band to the Edit Group. The upside of this is the convenience of being able to edit three frequencies +3 dB, for example, and then add another frequency to the pile and edit them all another +2 dB without having to reselect the first three. The downside is that you will have to deselect all four bands if you want to grab one more frequency and edit it by itself. 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 Setup mode page, press one of the [DOWN/UP] buttons. Button 3: Audition Automation (On/Off) This setting determines whether or not the Audition Automation function is active. When it is, the DEQ230 will cycle automatically through the programs in the Audition List. When it is not, the user must cycle through the Audition List manually. To enable or disable this function, press one of the [DOWN/UP] buttons. For a more extensive explanation of how to use Audition mode, turn to page 40. Button 4: Edit Time Out (On/Off) The Edit Time Out function serves as an "auto-exit" feature. When it is enabled, if you have not changed the gain value of any band or Edit Group for 30 seconds, the DEQ230 will exit automatically to Program mode. We have included this feature so the DEQ230 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 DEQ230 remain in Edit mode so you will not lose your chosen Edit Group when the unit returns to Program mode, you may want to turn the Edit Time Out function off. The default setting for this function is "Off;" to enable it press one of the [DOWN/UP] buttons. Button 5: Lock (On/Off) This function enables you to choose a particular program as the only one that can be selected once the DEQ230 is powered on. After this has been done, pressing any button besides the [POWER] button will cause the Numeric LED Display to show Lo for locked. This is handy for environments in which the DEQ230 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. Before you try this feature, make sure you're happy with the program you had selected prior to turning the unit off. It will be the program you are "stuck" with when you turn the unit back on after enabling the Lock feature. If you're already in Setup mode, all you have to do to enable this feature is press the fifth [BAND SELECT] button and then press one of the [DOWN/UP] buttons. You should see the LEDs over Channel B change from "OFF" to "ON." Then turn the unit off and on again. Your DEQ230 is now locked. (No fair using this knowledge to play tricks on your salesperson!) It's simple to restore the DEQ230 to full functionality (i.e., "unlock" it). Just turn the unit off and power it up in Setup mode again (turn the unit on and then hold down the [STORE] button). Then press the fifth [BAND SELECT] button and press one of the [DOWN/UP] buttons to turn this feature off. The next time you power up the DEQ230 it will operate normally.

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 is also called futzing, and can be used on any instrument or mix. Heres how to get that sound on the DEQ230: 1. Follow the instructions for items 1 and 2 from Step 2. 2. 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. 3. Use the [DOWN] BUTTON to reduce all of these frequencies until their LEDs are at -12 dB. 4. Select all of the unedited frequencies and boost them as high as you can without clipping the signal. 5. Be sure to toggle the [BYPASS] button to compare the result with the original.

Do not spray cleaning solution of any sort onto the front panel of the DEQ230. If a cleaning becomes necessary, spray a recommended cleaning solution onto a cloth first, and use the cloth to clean the front panel.

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. (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.) Cant edit program, cant select new program. Numeric LED Display keeps flashing Li. DEQ230 is locked. Channel B is linked to Channel A. Solution Test with a known good input. Replace the cables. Check the connections and the level of the mixer or amp to which the DEQ230 is connected. Increase level from source into DEQ230. Boost channel levels of quiet program. Boost Master Level in Setup mode. Reduce input level at source. Reduce gain of problem bands within program. Reduce channel levels of that program. Reduce Master Level in Setup mode. Unlock DEQ230 in Setup mode. Refer to page 46. Edit Channel A Unlink the Channels to allow independent edits to Channel B. Unlock DEQ230 in Setup mode. Refer to page 46. Set Release Edit Group function to On in Setup mode. Turn on power first, then hold down [STORE] button to enter Setup mode. Turn on power first, then press [DOWN/UP] buttons to re-initialize. Change Force Analog Input setting in Setup mode. Ditto.

Clip LED lights often.

Numeric LED Display keeps flashing Lo. Must de-select all bands in order to edit a single band. DEQ230 wont turn on/wont go into Setup mode DEQ230 wont turn on/wont re-initialize Analog input is ignored Digital input is ignored
DEQ230 is locked. Release Edit Group function set to Off. Holding down buttons when turning on power Holding down buttons when turning on power Digital signal present at S/PDIF Input Force Analog Input is set to Analog in Setup mode.
Refer All Servicing to Alesis
We believe that the DEQ230 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.

Obtaining Repair Service

Before contacting Alesis, check over all your connections, and make sure youve read the manual. Customers in the USA and Canada: If the problem persists, contact Alesis and request the Technical Support department. Make sure you have the units serial number with you. Talk the problem over with one of our technicians; if necessary, you will be given a return authorization (RA) number and instructions on how to return the unit. All units must be shipped prepaid and COD shipments will not be accepted. For prompt service, indicate the RA number on the shipping label. Units without an RA will not be accepted. If you do not have the original packing, ship the unit in a sturdy carton, with shockabsorbing materials such as Styrofoam pellets (the kind without CFCs, please) or "bubble-pack" surrounding the unit. Shipping damage caused by inadequate packing is not covered by the Alesis warranty. Tape a note to the top of the unit describing the problem, including your name and a phone number where Alesis can contact you if necessary, as well as instructions on where you want the product returned. Alesis will pay for standard one-way shipping back to you on any repair covered under the terms of this warranty. Next day service is available for a surcharge. Field repairs are not authorized during the warranty period, and repair attempts by unqualified personnel may invalidate the warranty. Customers outside the USA and Canada: Contact your local Alesis distributor for any warranty assistance. The Alesis Limited Warranty applies only to products sold to users in the USA and Canada. Customers outside of the USA and Canada are not covered by this Limited Warranty and may or may not be covered by an independent distributor warranty in the country of sale. Do not return products to the factory unless you have been given specific instructions to do so. Internet Address: Important information and advice is available on our web site: http://www.alesis.com Email may be addressed to Support@alesis.com.

Specifications

DEQ230D
Analog I/O (switchable) Input connectors: Output Connectors: Switch set to +4: Nominal input level: Maximum input level: Nominal Output Level: Maximum Output Level: Switch set to 10: Nominal input level: Maximum input level: Nominal Output Level: Maximum Output Level: Input impedance: Output Impedance: 2 balanced 1/4 TRS jacks 2 balanced 1/4 TRS jacks +4dBu (-15dBFS) +19dBu (6.9 Vrms) +4dBu (-15dBFS) +19dBu (6.9 Vrms) -10dBV (-16dBFS) +6dBV (2.0 Vrms) -10dBV (-16dBFS) +6dBV (2.0 Vrms) 10k 220

All measurements done over a 22 Hz - 22 kHz range with 1 kHz sine wave at -1dBFS input. Impedances are measured at 1 kHz.

DEQ230

Input connectors: Output Connectors: Nominal input level: Maximum input level: Nominal Output Level: Maximum Output Level: Input impedance: Output Impedance: 2 balanced 1/4 TRS jacks 2 impedance-balanced 1/4 TRS jacks -10dBV (-18dBFS) +8dBV (2.5 Vrms) -10dBV (-18dBFS) +8dBV (2.5 Vrms) 10k 220

Audio Performance

Signal To Noise Ratio: THD+N: Frequency Response: Power Consumption: >96 dB A-Weighted, Analog In to Analog Out <0.005%, Analog In to Analog Out 22-22kHz 0.50dB, Analog In to Analog Out 15 Watts Max (100-240 VAC / 50-60 Hz)

Mechanical

Size: Rack Spaces: Weight: 1.75" H x 19.0" W x 5" D 1 Space 3.0 lbs. (1.4 kg)

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.com/support/warranty.htm. During the warranty period ALESIS shall, at its sole and absolute option, either repair or replace free of charge any product that proves to be defective on inspection by ALESIS or its authorized service representative. In all cases disputes concerning this warranty shall be resolved as prescribed by law. To obtain warranty service, the purchaser must first call or write ALESIS at the address and telephone number available on the Alesis Website to obtain a Return Authorization Number and instructions concerning where to return the unit for service. All inquiries must be accompanied by a description of the problem. All authorized returns must be sent to ALESIS or an authorized ALESIS repair facility postage prepaid, insured and properly packaged. Proof of purchase must be presented in the form of a bill of sale, canceled check or some other positive proof that the product is within the warranty period. ALESIS reserves the right to update any unit returned for repair. ALESIS reserves the right to change or improve design of the product at any time without prior notice. This warranty does not cover claims for damage due to abuse, neglect, alteration or attempted repair by unauthorized personnel, and is limited to failures arising during normal use that are due to defects in material or workmanship in the product. THE ABOVE WARRANTIES ARE IN LIEU OF ANY OTHER WARRANTIES OR REPRESENTATIONS WHETHER EXPRESS OR IMPLIED OR OTHERWISE, WITH RESPECT TO THE PRODUCT, AND SPECIFICALLY EXCLUDE ANY IMPLIED WARRANTIES OF FITNESS FOR A PARTICULAR PURPOSE OR MERCHANTABILITY OR OTHER IMPLIED WARRANTIES. Some states do not allow limitations on how long an implied warranty lasts, so the above limitation may not apply to you. IN NO EVENT WILL ALESIS BE LIABLE FOR INCIDENTAL, CONSEQUENTIAL, INDIRECT OR OTHER DAMAGES RESULTING FROM THE BREACH OF ANY EXPRESS OR IMPLIED WARRANTY, INCLUDING, AMONG OTHER THINGS, DAMAGE TO PROPERTY, DAMAGE BASED ON INCONVENIENCE OR ON LOSS OF USE OF THE PRODUCT, AND, TO THE EXTENT PERMITTED BY LAW DAMAGES , FOR PERSONAL INJURY. Some states do not allow the exclusion or limitation of incidental or consequential damages, so the above limitation or exclusion may not apply to you. THIS CONTRACT SHALL BE GOVERNED BY THE INTERNAL LAWS OF THE STATE OF CALIFORNIA WITHOUT REFERENCE TO CONFLICTS OF LAWS. This warranty gives you specific legal rights, and you may also have other rights required by law which vary from state to state. This warranty only applies to products sold to purchasers in the United States of America or Canada. The terms of this warranty and any obligations of Alesis under this warranty shall apply only within the country of sale. Without limiting the foregoing, repairs under this warranty shall be made only by a duly authorized Alesis service representative in the country of sale. For warranty information in all other countries please refer to your local distributor.