FAQ: Electrostatic Speakers
Please refer to your product's manual. Manuals can also be viewed online by visiting the literature archive.
WOW! Are these speakers? I can see right through them!
Yes, MartinLogan's unique electrostatic sound reproduction technology makes it possible for them to be transparent AND sound incredible.
How do they work? What makes them sound so good?
The curved transparent panel that all MartinLogan ESL speakers use is called an electrostatic (ESL) transducer. The transducer converts energy from one state into another. The electrical energy from your amplifier is converted into mechanical energy via the motion of the ESL's diaphragm. This causes the air pressure in your listening room to rise and fall exactly as the recorded music does. The sequence of rising and falling air pressure is picked up by your auditory system and interpreted by your brain as sound.
The reason that MartinLogan ESL speaker systems reproduce sound so accurately is the patented electrostatic diaphragm that is driven directly by charged electrons. It is so ultra-thin it weighs less than the air it moves. Such a low mass diaphragm is ultra-responsive... so much so that it reproduces sounds at accuracy levels only associated with the finest audio electronics.
You experience each performance with stunning detail, power, and clarity.
How does the electrostatic design work?
The MartinLogan ESL transducer consists of a conductive diaphragm which is sandwiched between two curved conductive panels called Stators. The diaphragm is connected to a high voltage power supply which provides 2,500-3,500 volts of electricity at the diaphragm's surface.
The Stators are connected via a transformer to your power amplifier. As the amplifier sends its music signals to the Stator, an electrostatic field is created which pushes and pulls the charged diaphragm causing it to precisely track every change with the music.
What are some advantages of MartinLogan electrostatic speakers?
 Because the electrostatic diaphragm is essentially massless, it is capable of responding to each individual sonic event with extraordinary speed-from the most subtle background passages to the most explosive transients. There is no lag time which can distort the music. Instead you hear everything as the performer and composer intended.
 MartinLogan curvilinear line source electrostatic speakers output a more focused dispersion pattern, which maximizes the direct sound field and minimizes the reflected sound fields and room reverberation. This means that you experience more of the program as it was recorded. The sound stage is there, the original room acoustics are preserved and you are transported into the performance. For home theater it means that all of the final mix-effects, dialog and surround-are clearly and accurately reproduced.
 Real world sound sources radiate sound so that each frequency reaches the listener at exactly the right moment-without delay. This is one reason that real world sounds sound realistic. MartinLogan ESL loudspeakers utilize a single transducer capable of reproducing most of the audio spectrum. This unique property of ESL transducers means that MartinLogan speakers can cross-over at lower frequencies-typically 250 Hz-thus assuring that each audio event reaches your ear at exactly the right time. This means that the performance seems as real and detailed as the original.
I've heard that MartinLogan speakers are hybrid speakers. What is a hybrid speaker?
That is correct. Every MartinLogan speaker with the exception of the CLS IIz is a hybrid design. This means that they use both electrostatic and dynamic transducers to achieve maximum detail, imaging, and dynamic range. Every MartinLogan hybrid loudspeaker seamlessly fuses a curvilinear line source electrostatic transducer with one or more specially designed dynamic drivers that are perfectly matched to provide uniform frequency response with maximum dynamic range.
Where the electrostatic transducer uses a thin membrane and high voltage to produce sound, the dynamic transducer uses a paper, plastic, fabric or metal cone which is driven by a voice coil that moves back and forth through a magnetic field produced by the audio signal. Electrostatic speakers are perfect for reproducing sounds above 100 Hz, however both the size and power requirements at low frequencies make them less than optimum for faithfully reproducing very loud sounds below 100 Hz. Not so dynamic speakers which don't have the same sound reproduction capabilities above 100Hz but are great for playing low frequencies at extremely high volume levels.
Only MartinLogan provides you the best of both worlds. Whether you are listening to a delicate violin concerto or a blistering rock concert you will experience the living performance.
Do MartinLogan speakers require big or expensive amplifiers?
Absolutely not. MartinLogan speakers are quite efficient and are capable of providing from 89-91 dB output from only 2.83 volts of input. This makes them suitable for use with a wide range of discrete and integrated amps, receivers, and A/V receivers. Our hybrid designs will perform well with either a tube or transistorized amplifier, and will reveal the sonic character of either type.
Will amplifiers rated at 6 or 8 ohms work with MartinLogan electrostatic speakers?
All MartinLogan speakers are compatible with receivers rated at 4, 6 or 8 ohms. We have tested several mainstream, high quality receivers and have found all are more than capable of driving 4 ohm speakers. The limitations of an amplifier rated at 6 or 8 ohms only becomes obvious at extremely high sound volumes over a very extended time period. For most every other application an amplifier rated at 6 or 8 ohms will perform perfectly with MartinLogan speakers.
What size (power) of an amplifier should I use?
The power amplifier is one of the most important elements in any A/V system, as too little power will not allow your system to live up to its full potential. In general, we recommend an amplifier with 100 to 200 watts per channel for most applications. Probably less would be adequate for our smaller hybrids or when used in home theater where a subwoofer is employed. Our hybrid designs will perform well with either a tube or transistorized amplifier, and will reveal the sonic character of either type. However, it is important that the amplifier be stable operating into varying impedance loads: an ideally stable amplifier will typically be able to deliver nearly twice its rated 8 Ohm wattage into 4 Ohms and should again increase into 2 Ohms.
That said, you should consider both your musical tastes and the size of your listening room. What type of musical content do you prefer and what listening level do you like the best-ambient, loud, or somewhere in between?
For instance if your listening preferences lean more toward chamber music, solo, or acoustic performances, then a smaller power amp will be adequate. On the other hand, if you enjoy symphonic music or rock-particularly at live listening levels-then you will need a larger power amplifier. This is because, for the most part, chamber music doesn't require the extended volume range that symphonic or rock music performances do to fully reproduce the performance. Another important consideration is the size and character of your listening room. Character refers to its acoustic qualities. Does your room have a bright (reflective) or dull (absorptive) quality? Bright rooms are distinguished by their large flat hard surfaces, and dull rooms by their draperies and wall-to-wall carpeting. As a general rule larger rooms and duller rooms require more power to get the same live performance level.
Also, most multi-channel home theater/music systems incorporate amplified subwoofers (the .1 in 5.1, 6.1 and 7.1 channel home theater)which rely on your processor's bass management calibrations to reproduce the lower bass and sub-bass frequencies (80-100Hz and below). In this case, a portion of the power amp's output will be handled by the subwoofer amplifier, leaving more power available to the rest of the system. This allows the use of more moderately powered amplifiers while maintaining high levels of performance.
Your amplifier should also be capable of stable operation into a varying impedance load-delivering more power into lower impedance loads. This is because most musical content presents a constantly varying load to your amplifier with power requirements tied to the frequency of that content-as frequency rises, impedance drops and power requirements increase. The main idea is to have enough reserve power to handle transients like explosions, cymbal crashes, and other loud passages without overloading your amp.
Your MartinLogan Specialty Audio retailer has experience with a wide variety of amplifiers and receivers and can recommend the best components for your particular room size, listening habits, and MartinLogan speakers.
Could you suggest a list of power amplifiers and components that will be ideal for MartinLogan speakers?
With numerous excellent amplifiers available and the list growing practically each day, we can't recommend one amp over another simply because we haven't had the opportunity to audition them all. This is also true of each component in your A/V system-there are many great components to choose from. Your MartinLogan specialty audio retailer is experienced in assembling and installing a wide variety of MartinLogan loudspeaker systems and can recommend a system that suits your requirements.
Since MartinLogan speakers are capable of resolving subtle details, you can actually hear the differences between components as you swap them while listening to a familiar piece of music. Because of the signature that each component can add an individual character to the sound, it's important to take the time to match each one to your personal tastes.
Above all, trust your ears and carefully audition each element before making a final decision.
Will your electrostatic speakers harm my balanced amplifier?
No — all MartinLogan speakers are compatible with balanced amplifiers and will not damage the amplifier in any way.
Can you suggest a list of speaker cables that will be ideal for MartinLogan speakers?
Many people are surprised to hear that speaker cables and component interconnects can have a significant impact on the quality of sound. Just as with the amplifier questions above, there are many types and designs of cables to choose from and we haven't had the opportunity to extensively test them all. Therefore the best approach is to speak with your MartinLogan specialty audio retailer. They can recommend a variety of cable and interconnect options and work with you to find the best solution.
In fact, the cables should be matched to your components and speakers to assure that any additional sound signature or coloration is minimized or eliminated. Take the time to audition different cables and, as always... trust your ears.
I read in my manual that to achieve good imaging my speakers should be toed in. How much should I toe them in?
Generally it is found that the ideal listening position is with the speakers slightly toed-in so that you are listening to the inner third of the curved electrostatic transducer. A simple, yet effective method to achieve proper toe in involves sitting at the listening position, holding a flashlight under your chin and pointing it at each speaker. The reflection of the flashlight should be within the inner third of the electrostatic panel. Use this as a starting point and experiment by toeing in your speakers slightly less or slightly more. You will notice the tonal balance and imaging changing. You will notice that as the speakers are toed-out, the system becomes slightly brighter than when toed-in. This design gives you the flexibility to compensate for a soft or bright room.
What is the warranty period on a MartinLogan speaker system?
MartinLogan speakers have a 90 day warranty which can be extended to 5 years (3 years for subwoofers) by simply returning the warranty card along with a copy of the sales receipt, within 30 days of delivery. To read the complete warranty information click here.
How do I clean my speakers?
Use a dust free cloth or a soft brush to clean your speakers. We recommend a specialty cloth (available through the Xtatic Shop) that cleans better than anything else we have tried. If your speaker features EcoSound, please refer to the following FAQ.
How do I clean my EcoSound material?
We encourage you to occasionally apply finishing oil to maintain the EcoSound's rich dark color and keep your CLX loudspeakers looking their very best.
Using a soft, lint-free cloth, simply hand rub furniture grade finishing oil onto the EcoSound surface. We recommend natural orange or lemon fine furniture oil for best results. This easily repeatable process will always return your EcoSound to its original uniform luster.
How do I vacuum my MartinLogan speakers?
Vacuuming will be most effective if the speakers have been unplugged for six hours to twelve hours (i.e. overnight). You need not worry about the vacuum pressure damaging the "delicate" membrane. It is extraordinarily durable. Dirt and dust may be vacuumed off with a brush attachment connected to your vacuum cleaner, or you may blow them off with compressed air. When vacuuming or blowing off your panels do so to both sides, but focus the majority of your attention on the front of the panels.
Should I unplug my speakers during a thunderstorm?
Yes. Or before if possible. As with any high quality audio component it is always a good practice during stormy weather.
Is there likely to be any interaction between my speakers and the television in my Audio/Video system?
Actually, there is less interaction between a television and an electrostatic speaker than between a television and a conventional system. An unshielded ATF transducer can effect a CRT television. However, we do recommend that you keep your speakers at least one foot away from the television because of the dynamic woofer they employ. Certain center channel speakers are fully shielded and can go anywhere (see specs).
Will my electric bill go 'sky high' by leaving my speakers plugged in all the time?
No. A pair of MartinLogan electrostats will draw about 5 watts maximum. There is circuitry to turn off the static charge when not in use; however, actual consumption will remain close to the same. The primary purpose of the sensing circuitry is to prevent dust collection on the electrostatic element.
Could myself, my children, or my pets, be shocked by the high-voltage present in the electrostatic panel?
No. High voltage with low current is not dangerous. As a matter of fact, the voltage in our speakers is 10 times less than the static electricity that builds up on the surface of your television screen.
If the diaphragm was punctured with a pencil, stick, or similar item, how extensive would the damage to the speaker be?
Our research department has literally punctured hundreds of holes in a diaphragm, neither affecting the quality of the sound nor causing the diaphragm to rip. However, you will be able to see the actual puncture and it can be a physical nuisance. If this is the case, replacing the electrostatic transducer will be the only solution.
Will exposure to sunlight affect the life or performance of my speakers?
We recommend that you not place any loudspeaker in direct sunlight. The ultraviolet (UV) rays from the sun can cause deterioration of grill cloth, speaker cones, etc. Small exposures to UV will not cause a problem. In general, the filtering of UV rays through glass will greatly reduce the negative effects on the electrostatic membrane itself as well as woofers and other transducers.
Will excessive smoke or dust cause any problems with your electrostatic speakers?
Exposure to excessive contaminants such as smoke or dust may potentially affect the performance of the electrostatic membrane, and may cause discoloration of the diaphragm membrane. When not in use for extended periods, you should unplug the speakers and cover them with the plastic bags in which the speakers were originally packed. It is a good idea to vacuum the electrostatic portion of each speaker three or four times a year. See the vacuuming FAQ.
I have been advised that electrostatics do not fare well in the long term in the humidity of our tropical climate. Is this true?
We should tell you that MartinLogan indeed has a very substantial number of customers in tropical regions of the world. Our speakers have been serving them nicely for many years. This concern may have come from our earlier design of speakers, which were charged continuously.
Since 1993, all of our speakers have been designed so that they only charge the panel while music is being played. This improvement has made a tremendous difference in the consistent performance of our product. There may be a little more maintenance involved in humid regions when not in an air-conditioned environment. Simply enough, the concern is to keep the electrostatic panels dust free. Humidity will combine with any dust on the panel to make it slightly conductive. This will result in a slight pathway for the charge to leave the membrane of the speaker. The solution is simple. They only require occasional vacuuming with a strong vacuum hose.
I think my MartinLogan speakers have developed a problem. The right speaker is hissing even when the amplifier is disconnected.
Your speakers are dusty. See the vacuuming FAQ. The electrostatic charge on the element has attracted airborne dust or pollen. Since 1993, all of our speakers have been built with a charging circuit board that only charges the electrostatic element when music plays. At other times they are not charged and cannot collect dust. You can get the same benefit by simply unplugging them whenever they are not in use. A power strip is an easy way to do that.