Page 1
ACP-22 Two Channel Stereo Compressor/Limiter/Gate User's Manual VERSION 1.1...
Page 2
14 days of purchase. During the warranty period PreSonus shall, at its sole and absolute option, either repair or replace, free of charge, any product that proves to be defective on inspection by PreSonus or its authorized service representative.
Overview 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.
Page 6
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.
Page 7
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.com...
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); ·...
Page 9
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.
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.
Page 11
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.
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.
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.
Page 14
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.
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 ACP- 22 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...
Basic Setup & Applications 3.1 Some Basic Patching Inserting into your mixers insert points, unbalanced. After your mixers main outputs, balanced.
Page 18
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.
LED's above the threshold knob of the channel you're using flashing when you talk into the microphone. Make sure that the channel on the ACP22 has the following setup: Link button is out, Bypass is out, Auto is in, Soft is out, Gate Threshold knob is fully counter-clock wise, Compressor Ratio knob is set to 1:1 (fully counter clockwise).
Page 20
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.
Page 21
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.
Page 22
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.
Page 23
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 ...............>82db @ 10kHz Compression Threshold Range .......-40dBu to +20dBu Compression Ratio ..............1:1 to 20:1 Compressor Attack Time ..........0.1 ms to 200ms Compressor Release Time ..........0.05sec to 3sec Auto Attack and Release ........Program Dependent Gate Attack Range ............10uS to 100mS...
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).
Page 26
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'.