ACP-22 Two Channel Stereo Compressor/Limiter/Gate User's Manual VERSION 1.
PreSonus Limited Warranty PreSonus Audio Electronics Inc. warrants this product to be free of defects in material and workmanship for a period of one year from the date of original retail purchase. This warranty is enforceable only by the original retail purchaser. To be protected by this warranty, the purchaser must complete and return the enclosed warranty card within 14 days of purchase.
TOC Table of Contents 1 Overview 1.1 Introduction 1.2 Features 2 Controls & Connections 2.1 Front Panel Basic Layout 2.2 Compressor Controls 2.3 Gate Controls 2.4 Gain 2.5 Bypass & Link 2.6 Patch Panel 2.7 Power 3 Basic Setup & Applications 3.1 Some Basic Patching 3.2 Basic Applications 4 Technical 4.1 Specifications A Appendix A word about compression...
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Overview 1.1 Introduction Thank you for purchasing the PreSonus ACP-22 dual channel/stereo dynamics processor with full featured gates. This processor was designed using state of the art components to deliver crystal clear compression and noise gating for an infinite period of time. We believe that it is an exceptional sounding unit as well as an exceptional value. Feel free to contact us at 1-800-750-0323 anytime for any reason whatsoever.
Overview close range. The gate close range is useful for creating a more natural, acoustic sounding blend or mix. · Stereo Channel Linking. Using the Link function, you can link together both channels of the ACP-22 for stereo operation. When linked, both processors follow the setting of channel one which becomes the master. · Separate Bypass and Gain for Both Channels.
Overview To Get Help... Call Us: 1-800-750-0323, 9AM to 5PM, CST Visit our World Wide Web site: http://www.presonus.com Email Us: presonus@presonus.
Controls & Connections 2.1 Front Panel Basic Layout Notice that the front panel is divided into two identical sections. These are the two signal processing channels of the ACP-22. Each channel contains: · Compressor/Limiter; · Noise Gate; · Gain (output control); · Link & Bypass Control. 2.2 Compressor Controls Threshold The Compressor threshold sets the level at which the onset of compression begins. When the signal is above the threshold setting, it becomes 'eligible' for compression.
Controls & Connections Ratio Ratio sets the compression slope. This can be defined as the output level versus the input level. For example, if you have the ratio set to 2:1, any signal levels above the threshold setting will be compressed at a compression ratio of 2:1. This means that for every ldB of level increase into the compressor, the output will only increase 1/2dB, thus producing a compression gain reduction of 0.5dB. As you increase the ratio, the compressor gradually becomes a limiter.
Controls & Connections The Release control is only active when the Auto button is not pushed in. When the auto button is pushed in, the compressor automatically determines the appropriate release time for compression. Soft The Soft button selects from soft knee and hard knee compression curves. When this button is pushed in, soft knee compression curves are used, otherwise hard knee compression curves are used.
Controls & Connections 'CLOSE' LED above the threshold knob indicates when the gate is closed (the signal level is below the threshold). If the threshold is set fully counter-clockwise, the gate is turned off (always open), allowing all signals to pass through unaffected. Attack The gate attack time setting determines the rate at which the gate opens. Faster attack times are normally useful for gating percussive instruments such as drums, etc.
Controls & Connections frequencies at -12dB per octave. This feature is extremely useful when gating drums where it would be great to stop the cymbals from opening up the tom-tom gates, etc. 2.4 Gain Gain When compressing a signal, gain reduction usually results in an overall reduction of level. The gain control allows you to restore the loss in level due to compression. (Like readjusting the volume.) 2.
Controls & Connections 2.6 Patch Panel (Back) Input The input jacks are unbalanced tip/sleeve connectors or balanced XLR connectors. The input can handle up to +24dBu unbalanced or up to +18dBu balanced signal levels. Output The output jacks accept balanced XLR or unbalanced tip/sleeve connectors. The output will deliver up to +24dBu in signal level, balanced or unbalanced.
Controls & Connections +4/-10 Switch This switch adjusts the internal operating level of your ACP-22 when it is connected to line level (0dB = -10dBV) gear. With the switch in the '-10' position, the signal is raised internally so that it is processed at the lower noise floor of your ACP-22's internal circuitry. The signal level is lowered on the way out to match up with your line level gear's input.
Controls & Connections 2.7Power Power Connection The power jack on your ACP-22 accepts a standard IEC cord like those found on most computers and professional recording equipment. Your ACP22 contains a custom built in power supply, no wall wart. (We can't stand them either.) This way you can be assured of clean power combined with rugged construction that has been designed to last! Power Selection Before powering on your ACP-22 for the first time, be sure to check the position of the power selector.
Controls & Connections Notes...
Basic Setup & Applications 3.1 Some Basic Patching Inserting into your mixers insert points, unbalanced. After your mixers main outputs, balanced.
Basic Setup & Applications Between multi-track recorder inputs/outputs to mixer outputs/inputs, unbalanced. Sidechain insertion of an equalizer, for de-essinq specific frequency gating applications.
Basic Setup & Applications 3.2 Basic Applications Example setup compressing a voice or vocal track. Probably the most common use of a compressor is to limit the dynamic range of a vocalist during a live performance or a recording. It is almost always necessary to compress a vocal take during a recording session.
Basic Setup & Applications your mixer or multi-tracks meters read 0dB (in the case of some digital recorders this is -14dB). This would be a basic, very simple but useable setting for recording a vocal. Things to vary to suit your taste might be: adjusting the ratio and threshold for more/less dynamic range. Push the Soft button in and check out the Soft Knee compression curve. Take the compressor out of Auto mode and adjust the Attack and Release times to taste. Get a new vocalist (just kidding).
Basic Setup & Applications of the speakers and slap you in the face. This is more accentuated when using digital reverberation on the snare. Now you can adjust the Gate on the snare to stop those other drums from 'bleeding' through the snare mic: Turn the gate release knob to about the middle position, turn the gate attack knob to fully counter-clockwise, set the gate range to -60dB, adjust the gate threshold slowly clockwise until you begin to hear those other drums disappearing.
Basic Setup & Applications lots of other instruments such as distorted guitar, compressing the life out of your guitar will help you later in the mix. If the guitar is recorded as a solo instrument or part of an acoustic ensemble, you should experiment with less compression because you don't want to severely limit the natural acoustic dynamic range of a good sounding guitar. Start by using the setup described in the vocal section... De-essing using an inserted equalizer into the sidechain.
Basic Setup & Applications will eliminate all gain reduction and effectively turn off the gain reduction meters. The gain reduction is of course being derived from the master channel.
Technical 4.1 Specifications Number of Channels .............................................................................2 Dynamic Range..........................................................................>115dB Signal to Noise Ratio ...................................................................>95dB Headroom ..............................+24dBu, Unbalanced; +22dBu Balanced Frequency Response ......................................................10Hz to 50kHz Crosstalk ........................
Appendix A Word About Compression .... Punch, apparent loudness, presence.., just three of many terms used to describe the effects of compression/limiting. Compression and limiting are forms of dynamic range (volume) control. Audio signals have very wide peak to average signal level ratios (sometimes referred to as dynamic range which is the difference between the loudest level and the softest level).
Appendix compression destroys the acoustical dynamic response of a performance. ('Over compression', however, is used by some engineers as an effect, and with killer results!) Compressor/limiters are commonly used for many audio applications. A kick drum can get lost in a wall of electric guitars. No matter how much level is increased, the kick drum stays 'lost in the mud'. Add a touch of compression and tighten up that kick drum sound allowing it to 'punch' through without having to crank the level way up.
