Alesis Monitor One Active MK2 manuel d'utilisation

REFERENCE MANUAL ©2001 A LESIS C ORPORATION ™[...]

Alesis M1 Active Mk2 Reference Manual © Copyright 2001, Alesis Studio Electronics, Inc. All rights reserved. Reproduction in whole or in part is prohibited. “M1 Active Mk2” and “Superport” are trademarks of Alesis Studio Electronics, Inc. ALESIS CONTACT INFORMATION Alesis Studio Electronics, Inc. 1633 26th Street Santa Monica, CA 90404 USA[...]

Contents/Safety Warnings M1 Active Mk2 Reference Manual 1 C ONTENTS Introduction 2 I MPORTANT S AFETY I NSTRUCTIONS ...................................................... 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 Declaratio[...]

Contents/Safety Warnings 2 M1 Active Reference Manual I NTRODUCTION Thank you for purchasing the Alesis M1 Active Mk2 Biamplified Reference Monitors. To take full advantage of the M1 Active Mk2’s operation, and to enjoy long and trouble-free use, please read this user’s manual carefully. We value any comments you may have about this monitor sys[...]

Contents/Safety Warnings M1 Active Mk2 Reference Manual 3 I MPORTANT S AFETY I NSTRUCTIONS S AFETY SYMBOLS USED IN THIS PRODUCT This symbol alerts the user that there are important operating and maintenance instructions in the literature accompanying this unit. P LEASE FOLLOW THESE PRECAUTIONS WHEN USING THIS PRODUCT : 1. Read these instructions. 2[...]

Contents/Safety Warnings 4 M1 Active Reference Manual 10. Protect the power cord from being walked on or pinched, particularly at plugs, convenience receptacles, and the point where they exit from the apparatus. 11. Use only attachments or accessories specified by the manufacturer. 12. Use only with a cart, stand, bracket, rack, or table designed f[...]

Contents/Safety Warnings M1 Active Mk2 Reference Manual 5 I NSTRUCTIONS DE S ÉCURITÉ I MPORTANTES (F RENCH ) S YMBOLES UTILISÉS DANS CE PRODUIT Ce symbole alèrte l’utilisateur qu’il existe des instructions de fonctionnement et de maintenance dans la documentation jointe avec ce produit. Ce symbole avertit l’utilisateur de la présence d?[...]

Contents/Safety Warnings 6 M1 Active Reference Manual B EIM B ENUTZEN DIESES P RODUKTES BEACHTEN S IE BITTE DIE FOLGENDEN S ICHERHEITSHINWEISE : (G ERMAN ) 1. Lesen Sie die Hinweise. 2. Halten Sie sich an die Anleitung . 3. Beachten Sie alle Warnungen. 4. Beachten Sie alle Hinweise. 5. Bringen Sie das Gerät nie mit Wasser in Berührung. 6. Verwend[...]

Contents/Safety Warnings M1 Active Mk2 Reference Manual 7 I NFORMATION TO THE U SER FOR C LASS A D IGITAL D EVICE (FCC P ART 15, C LASS A) This equipment has been tested and found to comply with the limits for a class A digital device pursuant to Part 15 of the FCC Rules. These limits are designed to provide reasonable protection against harmful in[...]

Contents/Safety Warnings 8 M1 Active Reference Manual CE D ECLARATION OF C ONFORMITY This product conforms to current applicable CE standards for safety. For a detailed description of the standards used, please see the web site Alesis.com.[...]

About the M1 Active Mk2 M1 Active Mk2 Reference Manual 9 C HAPTER 1 A BOUT THE M1 A CTIVE M K 2 U NPACKING AND I NSPECTION Your M1 Active Mk2 Biamplified Reference Monitors were packed carefully at the factory, and the shipping carton was designed to protect the speakers during shipping. Please retain this container in the highly unlikely event tha[...]

About the M1 Active Mk2 10 M1 Active Reference Manual I NSIDE YOUR NEW SPEAKERS ✪ If you’re in a hurry to get started, skip ahead to Chapter 2, “Speaker Installation”, for connection and placement tips. A BOUT POWERED MONITORS The M1 Active Mk2s combine a speaker and amplifiers in the same compact cabinet. Powered monitors are growing in po[...]

About the M1 Active Mk2 M1 Active Mk2 Reference Manual 11 T ONE Tonally, every effort has been made to create a powered monitor that is as linear as possible, representing a flat frequency response from 50Hz to 20KHz ± 2dB. ( see p. 21) Additionally, the use of electronic crossovers within the critical upper midrange frequencies has reduced phase [...]

About the M1 Active Mk2 12 M1 Active Reference Manual T HE M1 A CTIVE M K 2 BI - AMPLIFIERS & ELECTRONIC CROSSOVERS The M1 Active Mk2 uses a 75W woofer amp and a 25W tweeter amp along with 4 th order high and low pass electronic crossover filters centered at 2000Hz. Electronic crossovers, which separate the frequencies before being sent to the [...]

About the M1 Active Mk2 M1 Active Mk2 Reference Manual 13 T HE M1 A CTIVE M K 2 POWER SUPPLY The M1 Active Mk2 employs a regulated switching power supply. This type of supply has previously only been available in amplifiers sold at the very high end of the Pro Audio market. Most power amp customers are familiar with the large transformer and output[...]

About the M1 Active Mk2 14 M1 Active Reference Manual W HY THE TWEETERS ARE OFFSET The M1 Active Mk2 speakers have been developed as a mirror-imaged pair with dual front mounted ports and an offset tweeter. In some applications, an extremely wide dispersion tweeter, such as used in the M1 Active Mk2, will exhibit response dips if mounted exactly on[...]

About the M1 Active Mk2 M1 Active Mk2 Reference Manual 15 A BOUT N EARFIELD MONITORING In the early days of recording, most recording studios used big monitor speakers almost exclusively. Unfortunately, they also required high powered amplifiers and expensive acoustic treatment (often poorly done) of the entire control room. Still, a well-construct[...]

About the M1 Active Mk2 16 M1 Active Reference Manual[...]

Speaker Installation M1 Active Mk2 Reference Manual 17 C HAPTER 2 S PEAKER I NSTALLATION Like any speaker system, your M1 Active Mk2 speakers will work best when properly positioned in a suitable acoustic environment. Achieving proper speaker placement is usually straightforward, but even with nearfield monitors, speaker placement and the acoustics[...]

Speaker Installation 18 M1 Active Reference Manual Monitors placed on the console’ s meter bridge can directly radiate back onto the console control panel causing a strong delayed reflection at the listening position Direct Path Reflection This kind of speaker placement also couples acoustic energy from the speaker's cabinet more readily int[...]

Speaker Installation M1 Active Mk2 Reference Manual 19 Careful consideration should also be given to the physical spacing between the speakers. Alesis recommends that the distance between the speakers for stereo applications equal the distance between the listener and either speaker. In other words, the listener and the two speakers are at the thre[...]

Speaker Installation 20 M1 Active Reference Manual S TEREO NEARFIELD PLACEMENT OF THE M1 A CTIVE M K 2 NOTE: We recommend that the M1 Active Mk2 speakers be placed with the tweeters to the inside , not the outside, of the listening triangle. The “classic” studio monitor layout used to be that the tweeters be placed to the outside of a horizonta[...]

Speaker Installation M1 Active Mk2 Reference Manual 21 H ORIZONTAL P LACEMENT R ECOMMENDATION Traditionally, proper horizontal placement of speaker systems slightly behind (not on ) a meter bridge accomplished two purposes : it allowed both woofer and tweeter to be at ear level, and many times, it permitted the recording engineer to see over the sp[...]

Speaker Installation 22 M1 Active Reference Manual V ERTICAL P LACEMENT R ECOMMENDATION 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 posit[...]

Speaker Installation M1 Active Mk2 Reference Manual 23 P LAYBACK 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 maste[...]

Speaker Installation 24 M1 Active Reference Manual P LUGGING 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 inaccu[...]

Speaker Installation M1 Active Mk2 Reference Manual 25[...]

Speaker Installation 26 M1 Active Reference Manual C ONNECTIONS 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[...]

Speaker Installation M1 Active Mk2 Reference Manual 27 P OWER SWITCH The POWER switch is located on the back panel. A blue power indicator lamp is on the front panel. I NPUT C ONNECTIONS 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 wi[...]

Speaker Installation 28 M1 Active Reference Manual But do NOT plug the speaker output of an amplifier, receiver, or similar device into the LINE INPUT jack. Use only line-level sources. Plugging too loud of a signal into the LINE INPUT jack may damage the electronics. Balanced +4 dBu line level sources : Professional recording and processing equipm[...]

Speaker Installation M1 Active Mk2 Reference Manual 29 T O SET THE LEVEL WITH A MIXER : 1. Turn on all system components (the M1 Active Mk2s last) and turn the M1 Active Mk2’s INPUT LEVEL control all the way down. 2. Play program through the mixer and raise the mixer’s fader levels until its meter averages around “0 VU”. 3. Raise the Contro[...]

Speaker Installation 30 M1 Active Reference Manual A VOIDING DAMAGE The best protection against speaker failure is to mix at a reasonable listening level. With a +4 dBu input and the input level control set to “6”, the M1 Active Mk2 speakers produce a sound pressure level (SPL) of 85 decibels at 1 meter, which is a good working level for mixing[...]

Surround Sound M1 Active Mk2 Reference Manual 31 C HAPTER 3 S URROUND S OUND A BOUT SURROUND SOUND Surround sound is the term used for several different systems which use multiple channels of playback in the listening room to recreate a truly three- dimensional sound experience. The practice of recording music-only in surround sound is a fairly rec[...]

Surround Sound 32 M1 Active Reference Manual C ENTER SPEAKERS IN MUSIC MIXES In video applications, with left, center and right channels all set to deliver equal output, the ear tends to hear dialog as coming only from the center channel . (It’s a psychoacoustic effect because all right and all left channel signals are fed to the center.) In Dolb[...]

Surround Sound M1 Active Mk2 Reference Manual 33 P LACEMENT OF THE CENTER M1 A CTIVE M K 2 SPEAKER IN THE STUDIO The left, center and right speakers should all be placed in an arc so that the distance of all drivers to the listener is identical (see page 29). The equilateral listening triangle as described earlier for stereo (two-channel) playback [...]

Surround Sound 34 M1 Active Reference Manual P LACEMENT OF REAR SURROUNDS The following suggestions for optimal M1 Active Mk2 placement are derived from several sources: 1) Standard industry practice for home installations as recommended by the manufacturers of surround encoder/decoder units; 2) recommendations developed by Tom Holman for setting u[...]

Surround Sound M1 Active Mk2 Reference Manual 35[...]

Surround Sound 36 M1 Active Reference Manual W ALL MOUNTING Once your have located the general area for the horizontal and vertical position, you need to find a wall stud. Attach shelving brackets or other commercial speaker-mounting device into the wall stud, then attach the M1 Active Mk2s to the mount, allowing room for the rear-panel input and A[...]

Surround Sound M1 Active Mk2 Reference Manual 37 M IXING FOR DISCRETE SIX CHANNEL REPRODUCTION : MATCHED VS . SPECIALIZED SPEAKERS While most speaker systems for monitoring music in surround use the same speaker cabinet in all positions, both front and rear, keep in mind that most consumer video surround installations use a different speaker in the[...]

Surround Sound 38 M1 Active Reference Manual mid bass (about 80Hz) on up. In the rear go the subwoofers and sometimes, small full range drivers which provide “ fill ” . So, in essence, today ’ s best car audio systems are designed to produce an enveloping environment very similar to that of a home theater. The use of M1 Active Mk2s (or any mo[...]

Troubleshooting M1 Active Mk2 Reference Manual 39 C HAPTER 4 T ROUBLESHOOTING T ROUBLESHOOTING I NDEX If you experience problems while using the M1 Active/Surround systems, please use the following table to locate possible causes and solutions before contacting Alesis Technical Support for assistance. Symptom Cause Solution Hum or buzz Ground loop [...]

Troubleshooting 40 M1 Active Reference Manual M AINTENANCE C LEANING The cabinet surfaces of the M1 Active Mk2 are covered with a vinyl laminate. Clean these surfaces when necessary with a lint-free cloth dampened in warm soapy water. USE ONLY A DRY CLOTH ON THE BACK PANEL OF THE POWER AMPLIFIER. Do not attempt to clean the cabinet with a brush (wh[...]

Troubleshooting M1 Active Mk2 Reference Manual 41 the drivers will not be pressed on by the packing in shipment. Shipping damage caused by inadequate packing is not covered by the Alesis warranty. Tape a note to the top of the unit describing the problem, include your name and a phone number where Alesis can contact you if necessary, as well as ins[...]

Specifications 42 M1 Active Reference Manual S PECIFICATIONS E NCLOSURE M ATERIALS AND C ONSTRUCTION Front baffle painted in metallic charcoal-gray, one inch (1 ” ) thick MDF with radiused edges to minimize diffraction. Sides and rear baffle covered in metallic charcoal-gray vinyl laminate, over five-eighths inch (0.625 ” ) thick MDF. Dual port[...]

Specifications M1 Active Mk2 Reference Manual 43 C ROSSOVER SECTION Crossover type: 4 th -order, 24dB/octave Linkwitz-Riley @ 2000Hz Input Impedance: 20k Ω balanced 10k Ω unbalanced Low Frequency Filter: 4 th order optimal Q high pass filter at 48Hz with +3 dB equalization A MPLIFIER S ECTION L OW F REQUENCY A MPLIFIER Rated power output: 75 wa[...]

44 M1 Active Reference Manual I NDEX 1/4 ” input plugs, 27 AC cables, 26 AC power, 13, 26, 43 amplifiers, 10, 12, 43 balanced, 27 biamplified, 10 center channel, 32 crossover, 11, 43 frequency response, 43 with ports plugged, 24 front baffle, 42 fuse, 13 Ground loop, 39 grounding, 26 INPUT LEVEL, 28 detent, 29 interference, 7 LINE IN, 27 Magnetic[...]

M1 Active Mk2 Reference Manual 45 A LESIS L IMITED W ARRANTY ALESIS CORPORATION ("ALESIS") warrants this product to be free of defects in material and workmanship for a period of one (1) year for parts and for a period of one (1) year for labor from the date of original retail purchase. This warranty is enforceable only by the original re[...]

46 M1 Active Reference Manual[...]