SMART COMPRESSOR USERS MANUAL Version 2.0 © 1997, PreSonus Audio Electronics, Incorporated. All rights reserved. Updated by J-Luck 2004 WARRANTY 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. 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. To obtain warranty service, the purchaser must first call or write PreSonus at the address and telephone number printed below to obtain a Return Authorization Number and instructions of 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 the PreSonus repair facility postage prepaid, insured and properly packaged. PreSonus reserves the right to update any unit returned for repair. PreSonus reserves the right to change or improve the 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. Any implied warranties, including implied warranties of merchantability and fitness for a particular purpose, are limited in duration to the length of this limited warranty. 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 PreSonus be liable for incidental, consequential 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 of limitation of incidental or consequential damages, so the above limitation or exclusion may not apply to you. This warranty gives you specific legal rights, and you may also have other rights which vary form state to state. This warranty only applies to products sold and used in the United States of America. For warranty information in all other countries please refer to your local distributor. PreSonus Audio Electronics, Inc. 501 Government St. Baton Rouge, LA 70802 (504) 344-7887 © 1997, PreSonus Audio Electronics, Incorporated. All rights reserved. TABLE OF CONTENTS 1. Overview A Word about Compression 1.1 Introduction 1.2 Features 2. Controls & Connections 2.1 Front Panel Basic Layout 2.2 Back Panel Basic Layout 2.3 Presets 3. Basic Setup & Operation 3.1 Quick Start 3.2 Basic Connections 3.3 Basic Operating Procedures 4. Technical 4.1 Specifications 1. OVERVIEW 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). The peak signal can cause overload in the audio recording or reproduction chain resulting in signal distortion. A compressor/limiter is a type of amplifier in which gain is dependent on the signal level passing through it. You can set the maximum level a compressor/limiter allows to pass through, thereby causing automatic gain reduction above some predetermined signal level or threshold. Compression refers basically to the ability to reduce the output level of an audio signal by a fixed ratio relative to the input. It is useful for lowering the dynamic range of an instrument or vocal, making it easier to record without distorting the recorder. It also assists in the mixing process by reducing the amount of level changes needed for a particular instrument. Take, for example, a vocalist who moves around in front of the microphone while performing, thus making the output level vary up and down unnaturally. A compressor can be applied to the 1 signal to help correct this recording problem by reducing the `louder' passages enough to be compatible with the overall performance. How severely the compressor reduces the signal is determined by the compression ratio and compression threshold. A ratio of 2: 1 or less is considered mild compression, reducing the output by two for signals greater than the compression threshold. Ratios above 10:1 are considered hard limiting. Limiting refers to the point at which the signal is restrained from going any louder at the output. The level of input signal at which the output is reduced is determined by the compression threshold. As the compression threshold is lowered, more and more of the input signal is compressed (assuming a nominal input signal level). Care must be taken not to `over compress' a signal. Too much 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. A vocal performance usually has a wide dynamic range. Transients (the very loudest portion of the signal) can be far outside the average level of the vocal signal. It is extremely difficult to ride the level with a console fader. A compressor/limiter automatically controls gain without altering the subtleties of the performance. A solo guitar can seem to be masked by the rhythm guitars. Compression can make your `lead' soar above the track without shoving the fader through the roof. Bass guitar can be difficult to record. A consistent level with good attack can be achieved with proper compression. Your bass doesn't have to be washed out in the low end of the mix. Let the compressor/limiter give your bass the punch it needs to drive the bottom of the track. 1.1 INTRODUCTION Thank you for purchasing the PreSonus Blue Max smart compressor/limiter with presets. Your Blue Max was designed with you, the end user in mind. As far as we know, it is the only compressor in the world with built-in compression presets. The presets were created not only to assist in setting up the compressor but to offer you the experience of professional engineers in using compression. If this is your first compressor, you will instantly gain valuable insight into what can be a confusing experience. The experienced user will gain a few tricks of the trade usually kept in the arsenal of professional engineers. This dynamics processor was built with state of the art components to deliver crystal clear compression for an infinite period of time. We believe the Blue Max to be an exceptional sounding unit at an exceptional price. We hope you agree. Feel free to contact us at 1-800750-0323 anytime for any reason. We value your comments and suggestions. Please pay close attention to how you connect your Blue Max to your system. Improper grounding is the most common cause of noise problems in both live and studio applications. We suggest you look at the connection diagrams which are part of this manual to insure optimum operation. 2 1.2 FEATURES The following is a summary of the features of the Blue Max: . . . . . . . . . PRESETS. There are 15 studio proven settings for voice, percussion, fretted instruments, keyboards, stereo processing and effects. VARIABLE INPUT CONTROL. In addition to normal stereo inputs the input control allows low signal levels such as direct output of electric guitars and basses to be increased to optimum levels. MANUAL MODE. Full operator control of ratio, attack and release is offered in manual mode. STEREO INPUTS/OUTPUTS. ¼ inch unbalanced stereo inputs (left side mono) and ¼ inch unbalanced stereo outputs (left side mono) for stereo recording and mix down use. FULL METERING. Full metering for input and output levels are available as well as separate meters for gain reduction. VARIABLE OUTPUT. Output control allows gain changes from - 20dB to +20dB. SIDECHAIN INSERT. Sidechain insert allows the Blue Max to be used for special processing applications such as de-essing and ducking. +4dBu OR -10dBV OPERATION. Internal operating levels are switchable from +4dBu to -10db V for system matching requirements. INTERNAL POWER SUPPLY. No Wall Wart! 2. CONTROLS & CONNECTIONS 2.1 FRONT PANEL BASIC LAYOUT The front panel on the Blue Max is divided into three sections. These are: 3 1. Presets: Fifteen detented preset positions and Manual select. The Presets for the Blue Max are controlled by this sixteen position rotary encoder. As the encoder is rotated, parameters are digitally switched, simultaneously controlling attack, release, ratio and threshold. 2. Controls: & Meters Input The Input control adjusts the gain on the input amplifiers for both channels. Amplification gain varies widely from -20dB to +40dB. The large range is necessary to amplify instruments such as guitar. Thus the input stage to the Blue Max is actually a pre-amp. Note: The input control is always active, even in manual mode. Ratio Ratio sets the compression slope. This is 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 (note: threshold is a preset parameter in the Blue Max) will be compressed at a compression ration 4 of 2:1. This simply means that for every 1dB 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. A limiter is defined as a processor that limits the level of a signal to the compression threshold. For example, if you have the ratio set to 20: 1, input set at 0dB, the output of the Blue Max will be limited to the internal threshold of the compressor, which is set to 10dB in manual mode. Note: The ratio control is only active in manual mode. Attack and Release Attack sets the speed at which the compressor `acts' on the input signal. A slow attack time (fully clockwise) allows the beginning envelope of a signal (commonly referred to as the initial transient) to pass through the compressor uncompressed, whereas a fast attack time (fully counter-clockwise) immediately subjects the signal to the ratio and threshold settings of the compressor. Release sets the length of time the compressor takes to return the gain reduction back to zero (no gain reduction). Very short release times can produce a very choppy or `jittery' sound, especially in low frequency instruments such as a bass guitar. Very long release times can result in an over compressed sound, sometimes referred to as `squashing' the sound. All ranges of release can be useful at different times however and you should experiment to become familiar with the different sound possibilities. Note: The Attack and Release controls are only active in Manual mode. Input / Output Meter The Input/Output meter shows the signal level being processed by the Blue Max. Input refers to the signal level being processed by the Blue Max before processing. Output refers to the signal level after processing. `0dB' on the meter is referenced to the +4/-10 switch on the rear of the unit. In +4 mode, 0dB = +4dBu. In -10 mode, 0dB = -l0dBV. Gain Reduction Meter The Gain Reduction meter indicates the amount of gain being reduced by the compressor in dB. 5 3. Output & Pushbuttons Output Level Control The Output control is used to set the desired output of the Blue Max. It is sometimes referred to as `gain makeup' control. This term is derived from the fact that as the compressor lowers the output level during gain reduction, the overall signal level is lowered, requiring the user to `makeup' the gain thereby restoring the original signal level. Input / Output Meter Select This button selects the function of the Input/Output meter. Pushed in, the meter gives you the level of the input signal. Pushed out, the meter gives you the level of the signal after compression; the output level. Process In/Out The Process button is similar to a bypass button except that the signal is still effected by the Input of the Blue Max. Pushed in, the Blue Max is processing the signal (compressing). Pushed out, th ...