Frequently Asked Questions

Why is electrostatic speaker technology claimed to be superior to other technologies?

There are two reasons for this claim. First, a properly designed electrostatic speaker has a lower moving mass than that of any other speaker technology. The unit mass of the membrane of Sound Lab speakers is significantly less than the unit mass of the air load it is moving. In fact, our speakers probably have the lowest moving mass of any speaker on the market. The benefits of this are several. When the membrane is commanded to stop or start, it does so without the delay that higher mass speakers exhibit. Also, since air-mass has the greatest influence on transduction characteristics, the speaker inherits the optimum damping characteristics of air. Transients are crisper and cleaner. Detail is much more apparent.

Secondly, the force that drives the membrane of our electrostatic speakers is evenly distributed over the entire radiating surface. Therefore, every point on the membrane is driven equally (iso-phasic) and the total membrane is always under tight control. As a result, the membrane can be very thin and flexible. Due to optimum damping and excellent signal compliance, distortion and irritation factors are extremely low.

How is it that Sound Lab's full-range electrostatic speakers have such profound bass response?

A patent has been awarded Sound Lab that describes and protects a method by which the single-frequency resonance energy of the membrane is distributed in a manner that equalizes for the loss of energy due to dipole cancellation (a problem with all dipole speakers). This development not only provides a flat, extended bass response but it also eliminates the undesirable membrane resonance peak.

Why are Sound Lab's Full-range Electrostatic speakers so big?

Good question. First, electrostatic forces are weaker than magnetic forces. Therefore, membrane excursions are limited. Since low-frequency acoustic energy is a function of the volume of air that is displaced by the membrane, limited linear displacement is compensated for by making the membrane area larger. However, this has a beneficial effect: the large membrane exhibits a more resistive coupling to the air. This means that less energy is thrown off to the sides in the form of eddy currents, which in turn reduces the reflected energy coming off of the side walls, which in turn improves imaging.

To produce a given loudness level, the speaker size must become larger as the low-frequency cut-off is lowered. Therefore, truly full-range dipole speakers must be larger than box speakers. The problem could be solved, as with conventional speaker technology, if the electrostatic panel was mounted in an enclosure, but then "box" resonance or "coloration" becomes a problem. The dipole configuragion provides the cleanest sound.

Why do your speakers need to be plugged into the wall outlet?

The electrostatic speaker works on the principle that "like" electrical charges repel one-another and "unlike" charges attract one-another. The membrane must be charged with a dense field of electrical charge in order for the speaker to function. This charge is created by a power supply that uses the AC power mains. Current drain is minimal. The typical current taken from the mains is on the order of only 15 milli-amps.

How far from the back wall should the speakers be placed?

The distance is not particularly critical. I would suggest about 3 feet. Toe the speakers toward each other slightly. If the speakers must be placed against the back wall, make the toe-in angle larger. Angles of up to 30 degrees are acceptable. This does not affect the sound quality since the speakers provide full spectrum sound over the entire dispersion angle.

What kind of grille cloth do you recommend?

All of the grille cloth we use is acoustical grade. I recommend our standard black double-knit fabric particularly because it has the least acoustical resistance. We have available a good assortment of fabric hues, all of which are acoustical grade.

What is the Optimum Room Size?

All of our speakers work well in a small room. From an acoustical standpoint, within reason there is no room too small. On the other hand, I would recommend our larger speakers for larger rooms.

Are Our Speakers Affected by Humidity?

Because of the non-hygroscopic nature of the materials used in our speakers, humidity has no measurable effect on speaker performance. We have had speakers in the Far-East for years that are still performing well.

Do Your Speakers Deteriorate With Time?

As long as the speakers are not abused like directly exposing them to water, sunlight, excessive heat, or other destructive environmental factors, or over-driving them, there is no deterioration with time. Properly cared for, your speakers should be considered heirlooms.

What is the Minimum Power that you Recommend?

I personally recommend 100 watts minimum. However, we have customers that use 30 watt single-ended triode amplifiers and find them to be satisfactory. The equivalent one-meter sensitivity of our speakers (measured at 4 meters) is approximately 88 to 100 db (depending on the equalization settings). This is typical of the more efficient high-end-quality speakers.

Are Your Speakers Difficult to Set Up?

Setup is a relatively simple procedure. Because of the wide full-spectrum dispersion of our speakers, hard reflections are eliminated. Furthermore, because of the wide range of equalization settings, virtually any room can be equalized without the need of electronic equalizers.

Which type of Amplifier works best, Tubes or Solid-State?

The real question is, which do you prefer? The high-impedance of our speakers in the lower frequencies (where the musical spectrum is most demanding) results in a greatly reduced current drain from the amplifier. So, both types of amplifiers run cooler, exhibit less distortion and last longer. Our speakers are very neutral and are not prejudiced, so what you prefer is what sounds best.

I hope that this section answers your questions. Browse the other sections on our website for further information. If you still have questions, please contact us.