User manual ALESIS M1ACTIVE

[. . . ] TM REFERENCE MANUAL © 2001-2005 ALESIS CORPORATION Alesis M1 Active Mk2 Reference Manual © Copyright 2001-2005, Alesis Studio Electronics, Inc. "M1 Active Mk2" and "Superport" are trademarks of Alesis Studio Electronics, Inc. ALESIS CONTACT INFORMATION Alesis Studio Electronics, Inc. E-Mail: Website: info@alesis. com http://www. alesis. com Contents/Safety Warnings CONTENTS Introduction 2 IMPORTANT SAFETY INSTRUCTIONS. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3 Safety symbols used in this product 3 Instructions de Sécurité Importantes (French) 5 Information to the User for Class A Digital Device (FCC Part 15, Class A) 7 CE Declaration of Conformity 8 ABOUT THE M1 ACTIVE MK2 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9 Unpacking and Inspection Inside your new speakers About Nearfield monitoring Avoiding reflections in the studio Stereo nearfield placement of the M1 Active Mk2 Connections Setting the Input Level control 9 10 15 17 20 26 28 SPEAKER INSTALLATION. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 17 SURROUND SOUND . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . [. . . ] Proper tweeter orientation is toward the stereo image center (the middle) as shown. This setup will promote a strongly focused center image such as for the vocalist. And because the (vocal) image width will be narrower than if the speakers are placed vertically, it will be possible to place the vocalist with great precision at stage center. In this orientation there will be much less chance of first reflections from either sidewalls or the console coloring your mix. M1 Active Mk2 Reference Manual 21 Speaker Installation VERTICAL PLACEMENT RECOMMENDATION Vertical placement of the M1 Active Mk2 as shown in Figure 3 is highly recommended. This position will simulate the soundfield that will be heard in most consumers' homes and (to a great extent) their cars. For this reason, even if the M1 Active Mk2s are positioned horizontally for all of the mixing, the vertical position should always be used in the final "playback check" mode. (See next section) There are a couple of possible drawbacks to vertical placement of a nearfield monitor relating mostly to room interaction effects. Vertical placement allows the M1 Active Mk2s to portray your mix with the widest and deepest soundstage possible, so many people in the control room have an image of the "sweet spot". However, this wide a dispersion pattern in a control room with walls in too-close proximity to the speakers can add strong reflections to the sound you hear, muddying your mix. Page 29 shows the control room placement/ distance recommendations, which should help you determine if your available recording space would work well with the M1 Active Mk2s set up vertically. 22 M1 Active Reference Manual Speaker Installation PLAYBACK CHECK MODE (VERTICAL MID-FIELD) After you've got your mix just right it's always good practice to perform a "playback check" by standing the M1 Active Mk2s vertically and making the listening triangle larger. The purpose of the playback check is to simulate what your masterpiece will sound like in a "typical" home listening environment. It is in this configuration that the imaging specificity of your mix can best be evaluated. Generally, in the playback check mode you want to arrange the speakers in the same equilateral listening triangle that you do in a nearfield setup, but instead of each side of the triangle being about 3 feet long, the distances between stereo speakers and to your listening position should be between 7 and 12 feet. When setting the left and right speakers vertically, place the tweeters toward the center with the ports toward the outside. In this vertical position, the M1 Active Mk2 becomes a "line source" speaker which is the most common home set up. (A 12" three-way with woofer on bottom, midrange in the center and tweeter at the top is a line source, as are most forms of tower speakers. ) When the M1 Active Mk2 is set vertically in its "column" configuration, the horizontal dispersion (left and right) of the speaker is widest, and the vertical dispersion (up and down) is narrowest. Unfortunately a vertical setup will also increase room effects, so there are minimum recommended setup distances from side and back walls: the speakers should be a minimum of 2. 5 feet from the side walls and 3 feet from the rear walls. After you've got the requisite distances from the side and back walls, it's often helpful to adjust the 7 to 12 foot equilateral listening triangle distances. What you want to find is the maximum distance that you can separate the two speakers while still holding a solid center image. If you get this placement correct and you've done a good job in the mix, you should be rewarded with a soundstage that accurately places the musicians in the width and depth perspective in which they were recorded. The sound should be very similar to what you heard at your mixing board, with possibly a little more ambience contributed by the listening room. The "other" playback check mode, sometimes considered of greater importance than the home environment, is to listen to your mix over a car audio system. [. . . ] Dampened linear rubber surround with moderate internal damping and constant linear displacement Nomex spider. Dual magnet structure uses top magnet in opposed ("bucking") configuration for magnetic shielding. HIGH FREQUENCY DRIVER: 1" silk soft-dome tweeter with special wave guide baffle. Low-viscosity ferrofluid cooling extends power handling while retaining impulse response capability. Dual magnet structure uses top magnet in opposed ("bucking") configuration for magnetic shielding. 42 M1 Active Reference Manual Specifications CROSSOVER SECTION Crossover type: Input Impedance: Low Frequency Filter: 4th-order, 24dB/octave Linkwitz-Riley @ 2000Hz 20k balanced 10k unbalanced 4th order optimal Q high pass filter at 48Hz with +3 dB equalization AMPLIFIER SECTION LOW FREQUENCY AMPLIFIER Rated power output: Distortion: Slew rate: Signal-to-Noise ratio: 75 watts, 6 load <0. 02% THD @ 30 watts/8 20Hz-20kHz 19V/µsec >110dB referenced to 60 watts @ 8, "A" weighted, 1kHz HIGH FREQUENCY AMPLIFIER Rated Power Output: Distortion: Slew rate: Signal-to-Noise ratio: 25 watts, 4 load 0. 025% THD @ rated power 9V/µsec >112dB @ rated output ACOUSTIC SECTION Free-Field Frequency Response: ±2dB, 50Hz to 20KHz Lower Cutoff Frequency: 40Hz -10dB Upper Cutoff Frequency: 23. 5KHz ­10dB Maximum Peak SPL per pair: 118dB SPL @ 1m Maximum short term SPL: 80Hz to 3. 0KHz 105dB SPL @ 1m GENERAL Power Consumption: AC Dropout Voltage: Weight: Dimensions (H x W x D): 120 watts with musical program, loud mix 12 watts quiescent (idle) 120V AC version: 80V AC 240V AC versions: 160V AC 19. 5 lbs. 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