User manual ALESIS M1 ACTIVE MKII REFERENCE MANUAL

[. . . ] 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 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 2 9 10 15 17 20 26 28 ABOUT THE M1 ACTIVE MK2 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9 SPEAKER INSTALLATION. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 17 SURROUND SOUND . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . [. . . ] Bear in mind that an expertly designed car audio system can approach the imaging and soundstaging capabilities of an optimally setup studio or living room, but most times this is NOT the case. The inherent limitations of an always-off-axis listening position and the variables of speaker placement, bass coupling (boost) in the small interior and numerous other factors make the car environment highly suspect. So, understand the sonic capabilities (and deficiencies) of your (or other) car audio systems, and evaluate your mix accordingly. M1 Active Mk2 Reference Manual 23 Speaker Installation PLUGGING THE PORTS TO ADJUST FOR ROOM ACOUSTICS The low frequency response of the M1 Active Mk2s can be custom tailored by plugging the ports. If the speakers must be placed less than one foot from a front wall, or if they are too close to a corner, then the bass may become exaggerated and inaccurate. The rules of thumb for these situations are as follows: a) less than 1 foot from a front wall but away from any corner: plug one port b) less than 1 foot from a front wall and a corner: plug both ports The "plug" can be wad of cloth to completely block the port(s) or a more porous material like fiberfill which will give less bass attenuation. The bass output of the M1 Active Mk2 is thus easily variable depending on in-room positioning and/or personal preference. If the M1 Active Mk2s are to be used in a system with a subwoofer, the proper blend of the two systems is critical if low-bass accuracy is to be maintained. If the subwoofer (such as the Alesis Point One) or preamplifier has 80Hz high-pass filters built-in for connection to the other amplifiers, then no port plugging is necessary. In the absence of an 80Hz high-pass filter feeding the M1 Active Mk2s, you'll need to experiment with various degrees of port plugging to minimize the cancellations and nodes that can occur from bass sources placed several feet apart in a room. In practice we've found that a single port plugged with cloth is usually the best compromise. It shows the approximate bass attenuation that can be expected with one port plugged. 24 M1 Active Reference Manual Speaker Installation M1 Active Mk2 Reference Manual 25 Speaker Installation CONNECTIONS The M1 Active Mk2 has been designed to be as simple as possible to set up and use. However, please follow the instructions to ensure that you get the best possible performance from your monitors. Before connecting the speakers, make sure the power switches of the M1 Active Mk2s and any equipment they will be connected to are turned OFF. AC POWER CABLE READ ALL SAFETY WARNINGS IN THE PREVIOUS SECTION OF THIS MANUAL TO ENSURE SAFE OPERATION OF THESE UNITS. Connect the M1 Active Mk2s to the specified power using the AC cables supplied. If the distance to your AC outlet is longer or shorter than the supplied cable, you may substitute an approved standard NEMA-to-CEE power cable of the correct length, available from most electronics stores. GROUNDING CONNECT THE M1 ACTIVES TO A PROPERLY GROUNDED OUTLET ONLY. DO NOT USE ADAPTERS WHICH REMOVE THE SAFETY GROUND PROTECTION OR CUT OFF THE GROUNDING PRONG ON THE POWER CORD. If you experience 60-cycle hum in your sound system as a result of different ground potentials between different units in your system, plug all units into the same AC circuit (if the total power load allows) and make sure other devices in the system are properly grounded themselves. The M1 Active features balanced inputs, so if it is properly connected to other balanced units, AC ground potentials will not affect the audio. If you cannot get rid of ground loops, consult a professional electrician familiar with sound system power designs. USE CLEAN POWER The M1 Active Mk2's internal power supply is designed to filter out most AC line noise. However, it is still good practice to plug your sound equipment into an AC circuit that is not shared with lighting dimmers, refrigerators, air conditioning units, or other appliances that may induce noise into the power system. 26 M1 Active Reference Manual Speaker Installation POWER SWITCH The POWER switch is located on the back panel. A blue power indicator lamp is on the front panel. INPUT CONNECTIONS Almost any conventional line-level source may be plugged into the M1 Active Mk2's LINE INPUT jack. The Line Input jack accepts both XLR and 1/4" input plugs wired either balanced or single-ended (unbalanced). [. . . ] Customers in the USA and Canada: If the problem persists, call Alesis USA at 1-800-5-ALESIS and request the Technical Support department. Talk the problem over with one of our technicians; if necessary, you will be given a return order (RO) number and instructions on how to return the unit. All units must be shipped prepaid and COD shipments will not be accepted. If you do not have the original packing, ship the M1 Active Mk2 in a sturdy carton, with shock-absorbing materials such as styrofoam blocks or "bubble-pack" surrounding the unit. [. . . ]