Alesis Computer Monitor Monitor One User Manual

ALESIS  
Monitor One  
Reference Manual  
 
CHAPTER 1: ABOUT THE  
MONITOR ONE  
Your new Alesis Monitor One™ Studio Reference Monitors will  
deliver accurate mixes in near-field digital and analog studio  
monitoring applications. The Monitor Ones offer wide frequency  
response, accurate transient reproduction, clear imaging and high  
power handling capability and were designed by experts with  
decades of experience in professional loudspeaker design.  
This speaker system uses a proprietary 6.5" high-power low  
frequency driver with a special mineral-filled polypropylene cone,  
a highly damped linear rubber surround and a 1.5" diameter voice  
coil wound on a high-temperature Kapton former. The 1" high  
frequency driver employed has a soft natural silk dome and is  
ferrofluid cooled. The system's crossover network uses low  
dielectric loss non-polarized capacitors and an oversized low-loss  
low frequency inductor. Rear panel connections are made via 5-  
way binding posts suited to large diameter wires as well as  
banana plugs.  
The cabinet design uses Alesis' exclusive SuperPort™ speaker  
venting technology. Most small speakers used for near-field  
monitoring give disappointing results in their lowest frequency  
range. They are either sealed (which limits the amount of air the  
driver can move) or have an undersized vent whose function at  
low frequencies and high acoustic output is nullified by the effect  
of turbulence in the restricted port tube. The Monitor One's large  
folded SuperPort overcomes this limitation by minimizing vent  
turbulence at high air velocities, thereby ensuring that the  
enclosure tuning remains stable, the acoustic output remains  
linear during heavy low frequency attack transients, and that the  
reactive load above and below box resonance seen by the driving  
amplifier does not dynamically shift in frequency. This all  
translates to tighter bass with higher definition.  
The Monitor One's 4 ohm load impedance takes advantage of  
today's modern professional amplifiers which are generally capable  
of a 1-3 dB increase in output power with 4 ohm loads over their 8  
ohm ratings. The result is a similar increase in the Monitor One's  
acoustic output over conventional 8 ohm monitors.  
Reliable handling of this additional acoustic output is ensured by  
the Monitor One's substantial power handling capability. Typical  
near-field monitors are rated at 50-60 watts maximum whereas the  
Monitor One carries a 120 watt continuous power rating and has  
1
 
been successfully tested to over 200 watts using the industry  
standard EIA-426A method. This a rugged speaker system  
designed for serious professional use.  
Covered with a non-slip rubber textured laminate for stable  
mounting, the Monitor Ones come in a mirror image left/right pair  
for symmetrical horizontal mounting.  
1.0 A LITTLE HISTORY  
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-constructed big monitoring system really was impressive to  
listen to, a fact not overlooked by the studio owners who wanted to  
impress the record company executives who paid for the big  
studio's time. These big systems had big level control knobs, and  
clients enjoyed "cranking-up" the volume.  
Fortunately, recording engineers and producers eventually  
learned that this was not the best way to accurately mix music  
because it wasn't the way people listened to their radios, cassettes  
and CD players (metalheads excepted). Also, big monitor systems  
and the costs for the required control room acoustic treatments  
were going through the roof (no pun intended), particularly beyond  
the budget limits of smaller project and home studios which were  
growing in numbers. A new way of accurate monitoring was  
needed: near-field monitoring.  
Near-field monitors, by their definition, are intended for  
mounting close to the listener. The idea here is to improve the  
direct acoustic path between the speaker and the listener by  
making it shorter, thereby giving less opportunity for the always  
present indirect (reflected) sounds to get back in and muddle  
things up. With near-field monitoring, the surrounding acoustic  
environment becomes a much less significant factor in  
establishing the monitor system's sound character.  
A good set of small monitors properly placed in a reasonably  
non-reverberant room and powered by a 100-watt amplifier will  
yield surprisingly accurate results at budget prices. Carried to  
another studio, the same monitor should also provide repeatable  
results. In fact, some recording engineers carry their own  
speakers around because they know how they will sound in  
almost any room. Now, even the big studios use smaller speakers  
2
 
to augment their big monitoring systems, and near-field monitors  
have become proven tools in the recording business.  
3
 
CHAPTER 2: INSTALLATION  
Like any speaker system, your Monitor Ones will work best  
when properly positioned in a suitable acoustic environment.  
Achieving proper speaker placement is usually straightforward,  
but even with near-field monitors, speaker placement and the  
acoustics of the listening room itself are too often overlooked and  
can become significant contributors to an inaccurate and  
uninspiring monitoring environment.  
Please take a moment to read this information carefully. It will  
help you to get the most use and enjoyment from your new Alesis  
monitors.  
2.0 SPEAKER PLACEMENT  
While near-field monitors are more forgiving of the  
surrounding room acoustics, it is always prudent to optimize the  
listening environment whenever possible. First, the user should  
be aware of the effect that the size of the listening room can have  
on low frequency response. In general, the smaller the room, the  
stronger the bottom end will be, although placement within a  
larger room can also make a difference. This has to do with the  
way low-frequency waves travel in closed spaces. If you find your  
monitor system to be either light or heavy on the bottom, try  
moving them around within your listening room. Also, because the  
Monitor One's SuperPort tube is located at the rear, position the  
monitors at least six inches away from anything that would block it.  
You should avoid locating your Monitor Ones near reflective  
surfaces such as glass, tile, large open walls or table tops. Still,  
many rooms used for recording have these surfaces, so the best  
way to deal with them is to place the monitors out in the room  
away from reflective walls, windows and sizable objects.  
Even with these reflective surfaces separated from the  
monitoring position, typical mixing situations usually still have the  
top surface of the mixing board to deal with. Unfortunately, the  
board itself can be a major source of reflections and the additional  
acoustic conduction into the board can affect your monitor's  
amplitude and phase response. Speaker placement on the  
console's meter bridge provides for two clear acoustic paths  
between the speakers and the recording engineer which results in  
undesirable comb filtering effects and poor imaging. The first path is  
the direct one, and the second is via a reflection off the mixer main  
4
 
control panel (as shown in Figure 1 below). This kind of speaker  
placement also couples acoustic energy from the speaker's cabinet  
more readily into the console's chassis. Both conditions should be  
reduced by placing the speakers on their own stands acoustically  
detached from, and slightly behind, the console as shown in Figure  
2. In this location, the reflective path off the console's control panel  
is now blocked by the meter bridge.  
Figure 1  
Direct Path  
Reflection  
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  
Figure 2  
—6”—  
Minimum  
Random  
Reflections  
Moving the monitors to a position behind the meter bridge causes  
the bridge to block the offending reflective path  
Careful consideration should also be given to the physical spacing  
between the speakers. Alesis recommends that the distance  
between the speakers equal the distance between the listener and  
either speaker. In other words, the listener and the two speakers  
are at the three corners of a triangle having equal- length sides.  
Figure 3 shows this concept. Note that both speakers are turned  
in somewhat, so that the prime listening position is directly out in  
front of each speaker. Applications that require monitoring by  
5
 
more than one engineer are accommodated by a smaller rotation  
of the cabinets. This will widen the prime listening position  
somewhat.  
Figure 3  
Right Monitor  
Left Monitor  
The speakers and  
listener should be at  
the three corners of  
a triangle having  
equal length sides  
Prime Listening Position  
Alesis has designed the Monitor Ones for horizontal mounting.  
This keeps their height profile as low as possible to minimize the  
recording engineer's visual obstructions. Your Monitor Ones are  
supplied as a symmetrical left-right pair, and if used this way,  
should be installed with the soft dome high frequency drivers  
towards the outsides of the triangle. The high frequency driver  
should be on the left side of the left monitor and on the right side of  
the right monitor (see Figure 4 below). Of course, the traditional  
method of mounting the speakers with the high frequency drivers  
at the top is perfectly acceptable too.  
Figure 4  
TM  
The high frequency driver should be on the left side  
of the left monitor and on the right side of the right monitor  
6
 
The Monitor Ones are completely covered with a non-slip rubber  
textured laminate whereas other speakers provide small stick-on  
pads (or nothing at all) to keep them from slipping around while  
they are playing. If you need to move the Monitor Ones or adjust  
their position slightly, lift them off the mounting surface first rather  
than attempting to slide them.  
2.1 CONNECTIONS  
Professional grade 5-way binding posts are provided for external  
wiring to the amplifier. This type of connector can accommodate  
bare or tinned wires, banana plugs and even spade lugs.  
About Wire: A lot of hype and confusion exists about the type of  
speaker wires to use, most of it created by the wire manufacturers  
themselves in an effort to have a unique story to tell. While this  
expensive wire will not hurt the speaker's performance at all,  
Alesis does not subscribe to most of this hype and chooses to take  
an approach based on science when recommending speaker  
wire. Our recommendation is simple; use the shortest length of the  
largest diameter wire you can get. #12-14 gauge multi-stranded  
speaker wire found at most hi-fi stores works very well. This kind  
of wire resembles oversized lamp cord and is very easy to work  
with.  
Before connecting the speakers, make sure your amplifier is  
turned OFF before making connections to it. Be sure you get the +  
terminals of the speakers wired to the + terminals of the amplifier.  
To help you do this, most speaker cable has a way to tell one  
conductor from another. Some use different-colored wires or  
insulation; others mold a small line or marker into one insulator to  
mark it. If one speaker's polarity is out of phase with the other, the  
result will be loss of low frequency response and stereo imaging  
when the system is played.  
In most cases, the speaker outputs of the amplifier will have a  
red terminal and a black terminal; these should be connected to  
the same-colored terminals of the Monitor One. Consult the  
manual of your power amplifier for specific information. In a  
properly-phased system, a positive input to the amplifier should  
result in a positive voltage on the red terminal, and push the driver  
forward.  
If you are using a dual banana plug connector, one side of  
the  
7
 
plug usually has a "GND" marker molded on it so you can keep  
polarity straight after unplugging and replugging. In standard  
practice, the GND side connects to the black terminal of the  
speaker.  
To connect wires to the terminals if you are not using a  
banana plug:  
1. Strip about 1/2" (15 mm) of insulation from the ends  
of each wire. If the wire is stranded, twist the strands together  
at the end.  
2. Turn the red and black terminal caps counter-clockwise until  
they reach their limit. As you do, the hole through the terminal  
post will be exposed.  
3. Insert the wires into the holes, observing proper polarity.  
4. Tighten the terminal caps so that they hold the wire firmly.  
Make sure no insulation is caught inside the terminal, to avoid  
a loose connection.  
2.2 POWER AND PROTECTION  
Alesis recognizes that professional speakers need to be strong to  
survive, so the Monitor One is designed to handle twice the power  
of other near-field monitors. This was achieved by using  
proprietary high power drivers and oversized crossover  
components, choices made principally to offer the user an  
extended margin of safety. Therefore, an amplifier with a  
100 watt power rating into 4 ohms, like the Alesis RA-100™  
Reference Amplifier, is recommend for most monitoring situations.  
Higher or lower power amplifiers may be used, depending on the  
size of the listening room and the engineer's preference for normal  
working levels.  
Be sure to verify that your amplifier is rated for 4 ohm speakers.  
Some older amplifiers are not and may fail if overloaded. Alesis is  
not responsible for any failures caused by the use of an  
inproperly-rated amplifier.  
Also, there is no situation where an amplifier rated beyond 200  
watts should ever be used because of the danger of damaging the  
Monitor One. To do so is asking for trouble and will void your  
warranty. On the other hand, if you use too small of a power  
amplifier, it is possible to damage the Monitor One if you run it into  
heavy clipping and distortion in an effort to get sufficient volume.  
This can lead to failures of both the amplifier and the speaker, as  
8
 
the amplifier’s clipping generates high frequency energy sufficient  
to damage the high frequency driver.  
Alesis does not suggest the use of any external protection  
devices, but considers such devices as fuses, lamps and/or  
thermal breakers safe to use, so long as they do not cause failures  
or require modifications to the Monitor One's construction which  
would void the warranty. Actually, many such devices are  
generally considered ineffective and can additionally alter the  
speaker's sound character, an undesirable trait for a studio  
monitor.  
The best protection against speaker failure is to mix at a  
reasonable listening level.  
Alesis thanks you for choosing our products. We value any  
comments you may have about this monitor system, this manual,  
your Alesis dealer and about our factory service. Please take a  
minute now to fill out your warranty card and tell us what you think.  
®Alesis is a registered trademark of Alesis Corporation.  
Monitor One, SuperPort, and RA-100 are trademarks of Alesis Corporation  
9
 
CHAPTER 3: SPECIFICATIONS AND  
SERVICE  
3.0 SPECIFICATIONS  
Drivers:  
6.5" low frequency, 1"  
silk dome high frequency  
2.5 kHz, 2nd-order filters  
(12 dB per octave)  
Crossover:  
Frequency Response:  
dB  
45 Hz - 18 kHz, ±3  
Power Handling:  
120 watts program, 200  
watts peak (using EIA-  
426A method)  
Nominal Impedance:  
Sensitivity:  
4 ohms  
88 dB SPL @ 1 watt and  
1 meter on axis  
Cabinet:  
Rubber textured laminate  
over 5/8" MDF with  
Alesis SuperPort on rear  
Dimensions:  
8.5"D  
Weight:  
15"W x 9.25"H x  
15 lb. each  
3.0A Architectural and Engineer's Specifications  
The loudspeaker cabinets shall each contain a 6.5" low frequency  
and a 1" silk dome high frequency driver, and be equipped with a  
passive crossover network with a crossover frequency of 2.5 kHz.  
The low frequency driver shall have a mineral-filled polypropylene  
cone, a damped linear rubber surround and a 1.5" diameter voice  
coil wound on a high-temperature Kapton former. The high  
frequency driver shall be ferrofluid cooled. The crossover network  
shall consist of a low-pass section feeding the 6.5" driver and a  
high-pass section connected to the 1" driver, with 2nd-order filters  
in each section using low dielectric loss non-polarized capacitors  
and an oversized low-loss low frequency inductor. Each cabinet  
shall be equipped with two 5-way binding posts for electrical  
connection to an amplifier recessed into the back of the cabinet.  
These posts shall accept heavy-gauge wire, standard banana  
plugs, or spade lugs.  
The cabinet shall be constructed of 5/8" thick MDF and be  
10  
 
covered in a dark grey rubber textured laminate. The cabinet shall  
have a large folded vent port tuned to extend the response of the  
low-frequency driver, using Thiele-Small parameter calculations  
adjusted for the effects of turbulence in the port during high-power  
operation. The cabinet shall measure 15" wide, 9.25" high, and  
8.5" deep, and weigh 15 pounds (Metric specification: 38.1 cm x  
23.5 cm x 21.6 cm, 6.8 kilograms).  
Each assembly shall exhibit a frequency response from 45 Hz to  
18 kHz, plus or minus 3 dB. Its impedance shall be 4 ohms, and  
be capable of handling 120 watts program material or 200 watts  
peak input using the EIA-426A testing method. It shall generate  
an 88 dB sound pressure level, measured at 1 meter with a 1 watt  
power input.  
The loudspeakers shall be the Monitor One Studio Reference  
Monitors from Alesis Corporation.  
3.1 MAINTENANCE/REPAIR  
INFORMATION  
3.1A Cleaning  
The cabinet surfaces of the Monitor One are covered with a  
textured rubber laminate. Clean these surfaces when necessary  
with a lint-free cloth dampened in warm soapy water. To preserve  
the textured finish, don't rub hard on the surface. Do not attempt to  
clean the cabinet with a brush (which may damage the surface) or  
a sponge (which may leave small crumbs in the texture).  
Do not attempt to clean either of the drivers.  
The Monitor Ones require no periodic maintenance.  
3.1B Service  
Before sending the Monitor Ones in for repair, make sure they are  
faulty and that the problem isn't being caused by something else  
in the system. Distortion or noise may be caused by a defective  
amplifier, preamp, cable, equalizer etc., or a loose connection in  
the system. Connect the Monitor Ones to a system that is known to  
be working properly to check whether the monitors have  
malfunctioned.  
Should service become necessary, YOU MUST FIRST CONTACT  
ALESIS TO OBTAIN A RETURN AUTHORIZATION NUMBER  
BEFORE RETURNING THE UNIT TO ALESIS OR AN  
AUTHORIZED ALESIS SERVICE FACILITY. If the unit is to be  
11  
 
repaired under warranty, you must provide a copy of the original  
sales receipt as evidence of date of purchase. Repairs will be  
made under warranty only after Alesis or an Authorized Service  
Center has determined in its sole discretion through inspection  
that the failure was not the result of overpowering, abuse, power  
surges, or defective components ahead of the Monitor One.  
OPENING THE MONITOR ONE OR ALTERING ANY OF ITS  
COMPONENTS WILL VOID THE FACTORY WARRANTY. To  
obtain repair after the warranty period, contact your dealer or  
Alesis.  
Outside the United States, contact your local distributor for  
repair information.  
12  
 

4XEM Security Camera IPCAMWFD User Manual
Accusplit Fitness Electronics AH120M9 User Manual
Acer Computer Monitor CRT Monitor User Manual
Acoustic Research Universal Remote ARRE433B User Manual
AEG Refrigerator 290 6I User Manual
Aiphone Cell Phone RA A User Manual
Air King Fan AK55L User Manual
Alphasonik Stereo Amplifier PMA1000HCE User Manual
American DJ DJ Equipment 700TM User Manual
AVerMedia Technologies TV Receiver MCE 2005 User Manual