User's Manual The Logos Center Channel
Important Contents Your Logos speaker is provided with an automatic Limited 90 Day Warranty coverage. Introduction 3 History 4 The Electrostatic Concept 6 Martin-Logan Exclusives 7 Installation Options 8 Operation 9 You have the option, at no additional charge, to receive Limited 3 Year Warranty coverage.
Introduction Congratulations, you have invested in the world's first electrostatic hybrid home theatre speaker! The advantages of Martin-Logan hybrid technology will present themselves to you from moment the movie begins. The box effect (a phenomenon similar to cupping your hands around your mouth when speaking) produced by dynamic midrange drivers is absent and the natural openness of the human voice comes through. Never before in home theatre has the midrange been so clear.
History In the late 1800’s, any loudspeaker was considered exotic. Today, most of us take the wonders of sound reproduction for granted. It was 1880 before Thomas Edison had invented the first phonograph. This was a horn-loaded diaphragm that was excited by a playback stylus. In 1898, Sir Oliver Lodge invented a cone loudspeaker, which he referred to as a “bellowing telephone”, that was very similar to the conventional cone loudspeaker drivers that we know today.
In 1947, Arthur Janszen, a young Naval engineer, took part in a research project for the Navy. The Navy was interested in developing a better instrument for testing microphone arrays. The test instrument needed an extremely accurate speaker, but Janszen found that the cone speakers of the period were too nonlinear in phase and amplitude response to meet his criteria.
The Electrostatic Concept How can sound be reproduced by something that you are able to see through? Electrostatic energy makes this possible. nique is known as push-pull operation and is a major contributor to the sonic purity of the electrostatic concept due to its exceptional linearity and low distortion. Since the diaphragm of an electrostatic speaker is uniformly driven over its entire area, it can be extremely light and flexible.
Martin-Logan Exclusives Vapor Deposited Film The diaphragm material used in all Martin-Logan speakers employs an extremely sophisticated vapor deposited conductive polymer membrane. A proprietary conductive compound is vaporized then electrostatically driven into the surface of the polymer film in a vacuum chamber. This process allows an optically transparent membrane, adds no mass to the diaphragm and is extremely uniform in its surface resistivity characteristics.
Installation Options On a television: If your television provides a wide and stable enough platform, the shielded Logos can be placed on it. Rubber feet are included with the Logos bracket to prevent it from scratching the top of your television and to keep the Logos from vibrating. On the Wall: The Logos includes a wall mounting kit allowing you to mount the Logos on the wall or ceiling without locating a stud.
Operation -Hazardous voltages exist inside, do not remove cover -Refer servicing to a qualified technician -To prevent fire or shock hazard, do not expose this module to moisture -Use only with grounded outlet -Turn amplifier off and unplug speaker should any abnormal conditions occur -Do not operate if there is any visual damage to the electrostatic panel element -Do not over drive speaker beyond its rated power AC Power Connection Because your Martin-Logan Logos uses an internal power supply to energize
Logos bracket assembly / setup (revised 3-99) flat edge Revised contents of accesory kit TO 1 ea. - Logos speaker 1 ea. - Mounting bracket 2 ea. - 1.75 in. dia. Metal cylinders 2 ea. - 1/2 in. x 2.5 in. Button head bolts 1 ea. - 5/16 in. Allen wrench 6 ea. - Rubber feet 4 ea. - 1/4 in. x 2 1/2 in. Hex head lag screws 4 ea. - # 12 washer P TOP BO T TO M BOTTOM Arm Mounting the Logos on the Wall or Ceiling flat edge side view of arm Figure 1.
Step 3. Drill a 9/64 in. pilot hole through one of the upper (for the top of the bracket) pencil register marks you made in the previous step. Get out your level, you’re going to need it for the next step. Get your assistant to hold the bracket in place while you secure the first lag screw through the bracket in the pilot hole you just drilled. Check for level as shown (figure 3) and make any changes necessary to the register marks you made previously. Unscrew the lag bolt and remove the bracket. Step 4.
Room Acoustics Your Room This is one of those areas that requires both a little background to understand and some time and experimentation to obtain the best performance from your system. this wave experience like a 3 dimensional pool with waves reflecting and becoming enhanced depending on the size of the room and the types of surfaces in the room. Your room is actually a component and an important part of your system.
Resonant Surfaces and Objects Objects. All of the surfaces and objects in your room are subject to the frequencies generated by your system. Much like an instrument, they will vibrate and “carry on” in syncopation with the music and contribute in a negative way to the music. Ringing, boominess, and even brightness can occur simply because they are “singing along” with your music. Clap your hands. Can you hear an instant echo respond back? You’ve got near-field reflections. Stomp your foot on the floor.
Dispersion Characteristics Controlled Horizontal Dispersion Controlled Vertical Dispersion Your Logos launches a 30 degree dispersion pattern when viewed from above. This horizontal dispersion field gives you a choice of good seats for the performance while minimizing interaction with side walls. See Figure 1. As you can see from the illustrations, your Logos speaker projects a controlled dispersion pattern. See Figure 2.
Home Theatre It has long been the practice of stereo buffs to connect their television to the stereo system. The advantage was the use of the larger speakers and more powerful amplifier of the stereo system. Even though the sound was greatly improved, it was still mono and limited by the broadcast signal. Surround Speaker (dipole design) Subwoofer Rear Projection Television In the late 1970's and early '80's two new home movie formats became widely available to the public; VCR and laser disc.
Questions What amplification should I use with my A/V system? Unfortunately the most often asked question regarding amplification is the most difficult to answer and that is “How much power do I need?” The best advice we can offer is that you consider that video is very dynamic and the peak energy demands can last much longer than in most musical presentations. Therefore it is our recommendation that your A/V amplifiers be at least as large if not larger than your current audio amplifier.
Troubleshooting No Output Check that all your system components are turned on. Check your speaker wires and connections. Popping and Ticking Sounds, Funny Noises These occasional noises are harmless and will not hurt your audio system or your speakers. All electrostatic speakers are guilty of making odd noises at one time or another. Check all interconnecting cables. Weak Output, Loss of Highs Check the power cord. Is it properly connected to the speaker? Lack of Bass Check your speaker wires.
Glossary AC AC. Abbreviation for alternating current. Active crossover crossover. Uses active devices (transistors, IC’s, tubes) and some form of power supply to operate. Amplitude Amplitude. The extreme range of a signal. Usually measured from the average to the extreme. Arc Arc. The visible sparks generated by an electrical discharge. Bass Bass. The lowest frequencies of sound. Bi-Amplification Bi-Amplification.
Midrange Midrange. The middle frequencies where the ear is the most sensitive. Passive crossover crossover. Uses no active components (transistors, IC’s, tubes) and needs no power supply (AC, DC, battery) to operate. The crossover in a typical loudspeaker is of the passive variety. Passive crossovers consist of capacitors, inductors and resistors. Phase Phase. The amount by which one sine wave leads or lags a second wave of the same frequency. The difference is described by the term phase angle.
Specifications Frequency Response 75-20,000 Hz +/- 3dB Sensitivity 89dB 2.83 volts/meter Impedance Magnitude Nominal: 5 ohms • Minimum: 2.75 ohms Crossover Frequency 300, 3500 Hz • 12dB per octave Woofer 6.5" (16.5 cm) magnetically shielded in a sealed cabinet Midrange Two 17" x 9.25" (43.2 cm x 23.5 cm) curved electrostatic panels, vapor deposited polyester film with proprietary insulated stators Tweeter .55" (1.
Notes Logos User's Manual Page 21
$ 5.00 2001 delaware street, p.o. box 707, lawrence, kansas 66044 ph: (785)749-0133, fax: (785)749-5320 www.martinlogan.com © 1997 martin-logan ltd.
