Detailed meanings & applications of the Technical Terms that we used
Copyright (c) 2003 HOMETHEATER 2U. COM., E Direct International, LLC. All rights reserved.

A to C
2-Way, 3-Way, 2.5-Way I 5.1, 6.1, and 7.1-Channel Surround Sound I Band-Pass Subwoofer I Basket I Bass Mid-Range I Bass Reflex System I Binding Posts ( 5-way ) I Bipole ( Bipolar ) I Bi-Wire ( real ) I Butyl Rubber I Center Channel Speaker I Cone I Crossover I Crossover Frequency

D to N
Damping (or Dampen) I Diaphragm I Dome I Doped I Diffraction I Driver I Dust Cap I Efficiency I
Ferro-Fluid Cooled I Frequency Response I Grille I Hi-Pass, Band-pass, Low-Pass I Impedance I Impedance Equalization Circuit I Litz Wire I M-T-M ( D'Appolito ) I MDF I Midrange I
Neodymium Magnet

O to S
Octave I OFC ( Oxygen-Free Copper ) I  Orders Of Crossovers I Passive Crossover I Passive Radiator I Phase, In Phase, Out Of Phase I Phase Plug I Point-Source I Polypropylene I Recommended Amplifier I Satellite Speakers I Sensitivity ( dB /1m/2.83v ) I Stereo I Subwoofer I Surround Speakers

T to W
Timbre I Titanium Dome I Transmission Line I True Piano Mirror-Finish I Tuned Port I Tweeter I Video Shielding ( Magnetic Shielding ) I Voice Coil I Woofer

2-Way, 3-Way, 2.5-Way?

These terms refer to the number of frequency bands a speaker system's output is divided into.
Two-way: A speaker system that uses two types of drivers to cover the entire audio spectrum.
Three-way: A speaker system that uses three types of drivers to cover the entire audio spectrum.

Our two-way system typically has 1 or 2 bass mid-range driver(s) and a dome tweeter. A three-way system will add a woofer to that configuration. We use a passive crossover network that enables each driver to reproduce a selected band, which maximizes the linearity and frequency response of the cabinet.

2.5-way system is the special term we use to describe a two-way system plus a passive radiator, which looks like a woofer minus the magnet & voice coil (0.5).top

5.1, 6.1, and 7.1-Channel Surround Sound.

A setup with six discrete digital audio channels includes 5 full bandwidth and 1 "low frequency" channel ( ".1", for its limited range of frequencies.) The full bandwidth channels account for the front left & right speakers, the center speaker, and the left and right surround speakers, while a subwoofer takes care of the low-frequency effects. A 6.1-channel system adds a rear surround speaker to the setup, and a 7.1-channel system adds another rear surround speaker.

We sell our speaker systems as 5.1 setups, but you can easily add extra surround or bookshelf speaker(s) to form a 6.1 or 7.1-channel system. Don't forget, you will get more package

Band-Pass Subwoofer

The band-pass is a design which features a sealed top chamber and a ported bottom chamber that acoustically rolls off upper frequencies. Acoustic dampening material is also applied to the ported chamber to further eliminate mid/high frequencies.

Large diameter woofers are not needed in our band-pass subwoofer because the air load is in the coupling cavity, not in open air. Band-pass speakers make excellent subwoofers because they produce deep, clean, powerful bass sounds in practical-sized enclosures.

Our band-pass subwoofer has some distinct advantages over traditional direct-radiating subwoofers, such as hiding distortion and a higher efficiency (higher SPL). In addition, the sealed top chamber protects the subwoofer(s) from damage associated with demanding low frequency cone excursion. Our subwoofers are fully encased within the cabinet, which protects them from physical


The basket is the outside frame of the speaker that holds the dome or cone suspension system and the magnet assembly. It is important for it to be constructed out of one piece of material to prevent any rattling at high volumes.

Many of our speaker baskets are even cast out of aluminum for extra strength with less

Bass Mid-Range

The segment of the audio frequency spectrum covering sounds produced in the upper bass and midrange region is called the bass mid-range.

Our special bass mid-range drivers can be used to reproduce these frequencies. Combined with phase plug & base reflex system designs, they offer a natural and transparent mid-range with deep extended bass response .top

Bass Reflex System

A bass reflex speaker system utilizes a "tuned" port in its enclosure and regulates sounds created by the backward motion of the woofer. This reinforces rather than conflicts with the front wave.

Our system is carefully tuned by the length and size of the opening (port), sometimes together with a passive radiator to increase & extend bass response, to improve efficiency at low frequencies. Bass reflex designs are more power-efficient than acoustic suspension designs — they'll play louder than an acoustic suspension speaker when driven with the same amplifier

Binding Posts ( 5-way )

5-way binding posts are a versatile type of terminal, used very often on high-end speakers for its flexibility and ease of use. They consist of a metal shoulder with a protruding threaded rod which can be tightened down. The term five-way comes from its ability to connect to multiple wire termination methods: a bare speaker wire, pin connectors, spade connectors, banana plugs, and dual banana plugs.

We use 5-way gold plated binding posts as the standard terminal for most of our speakers to ensure the best possible conductivity and corrosion resistance. Our Chopin LE series uses the German made WBT© 5-way Binding Posts for the utmost performance. top

Bipole ( Bipolar )

A bipolar speaker uses two drivers facing two directions. These drivers radiate sound equally and operate in phase with each other. Bipolar speakers produce a somewhat diffuse sound field, but there is still some direct radiation at the listener. A bipolar speaker design is often utilized to create a diffuse rear channel in a Pro-Logic surround environment.

Our bipole surround speakers utilize two "sets" ( instead of just two) of drivers ( tweeter, Bass Mid-Range ) and bass-reflex systems to cover the entire audio spectrum and to extend bass response. By doing so, we can ensure you a true cinema experience that ordinary surround speakers simply cannot

Bi-Wire ( real )

Bi-wiring involves connecting two separate runs of wire to your speakers with both sets of cables connecting to the same set of channels on your receiver or amplifier. Many audiophiles find that it offers improvements in imaging and detail.

The term "real" is used to distinguish our designs from some "fake" bi-wire designs, which do not use a special type of crossover with separate "high-pass" and "low-pass" sections.

The dual sets of terminals also work fine with a single set of speaker cables. Actually, they come from our factory set up for conventional operation, with "jumpers" installed between the two sets. These jumpers can be easily removed for bi-amping or

Butyl Rubber

Butyl rubber is not synthetic and 100% natural in origin.

It is commonly used for the compliant suspension of our drivers and is chosen for its durability to UV resistance, heat and humidity. top

Center Channel Speaker

The center channel speaker is the key component in a Pro-Logic or Dolby Digital Surround audio system. The center channel reproduces 50% of an entire movie sound track and over 90% of the dialogue. Its primary function is to stabilize the center of the reproduced soundstage for off-center listeners.

Our center channel speakers utilize bass reflex systems with a Point-Source design in M-T-M format, to cover the entire audio spectrum and to extend bass response. Our Polar Light series even includes a top firing woofer to ensure clear, articulate dialogue and sound, along with deep powerful bass.

Special care has been taken to keep our center channel timbre matched to that of the front speakers. This is important in providing a smooth transition as sounds move from one speaker to the


The cone is the portion of a driver that is attached to the voice coil. It excites the air as the coil moves. Although the voice coil does most of the actual work in a speaker, the speaker cones account for the sound that you hear. The main purpose of a cone is to increase the radiating area of the voice coil while maintaining a rigid form.

Most of the cone material we use is paper with silk or wool fiber, a sounding material proven excellent. We also use titanium in the Polar Light & Chopin series, and aluminum and polypropylene in the Rose series for its special application. One cannot effectively choose speakers based on materials alone. The best way to choose a speaker system is still to listen to it at your own


The crossover is an electronic (or passive) filter that divides up the frequency spectrum and routes them to the amplifiers or speakers that are best suited to reproduce a given range of frequencies.

The filters used within our speakers are passive crossovers. They do not require any external power and are performed to the signal at the speaker level. It is the crossover's job to send high frequencies to the tweeter and low frequencies to the woofer (along midrange frequencies to the midrange driver in a 3-way speaker).

Additionally, our crossovers contain an Impedance Equalization Circuit to stabilize the impedance load of the speaker and shape the frequency

Crossover Frequency

, The crossover frequency is the frequency at which audio signals are divided and routed to the appropriate driver in a crossover network (low frequencies to a woofer, midrange frequencies to the midrange driver and high frequencies to a tweeter).top

Damping (or Dampen)

Damping is the ability of a material to decrease unwanted vibrations.

On our drivers, a special cone coating and surrounding material is used to minimize vibrations within the diaphragm, resulting in a flatter frequency response. Overall movement of the cone can also be dampened electrically and mechanically through the voice coil and its suspension.

Within speaker cabinets, high graded damping materials are generously applied to reduce wall vibrations, and also to absorb acoustic energy from within the cabinets


The diaphragm is the part of a driver attached to the voice coil. Its movement produces sound.

The diaphragm for a woofer is a cone, and often a dome for a


A dome is a driver that has a dome-shaped diaphragm. This is very effective with higher frequencies in dispersing sound over a wide area. It has the advantage of improved dispersion with less diffraction over a cone driver.

We use dome drivers for all of our tweeters: mostly silk domes (convex), and sometimes titanium domes (convex or concave). Concave types are more efficient but convex types have better dispersion. Both are lightweight in order to sustain the rapid movements required to produce higher


A doped is a thin layer of viscous material that is added to the surface of drivers. We have developed our own special formula to dampen resonances within the diaphragm


Diffraction is a series of constructive and destructive interferences caused by the sound waves moving past an


A driver is the device that compresses and rarefies the air to create sound waves. Driver types include woofers, tweeters, midranges, domes,

Dust Cap

A dome-shaped cap that is sealed around the center of the speaker to prevent dust and debris from entering the small gap around the voice coil, and consequently, destroying it.

Dust caps can have an negative impact on the sound. Fortunately, our patented single molded cone totally eliminates the need of a dust cap and its potential


Efficiency is the measure expressed in relative dB (decibels) of how much acoustic output a driver will produce with a given amount of input power.

An efficiency measurement can be useful when matching an amplifier to a particular speaker. Efficiency indicates nothing about sound quality, but only the quantity of acoustic energy for a given input power. A more common way of expressing speaker efficiency is

Ferro-Fluid Cooled

Ferro-fluid has magnetic particles that allows it to be attracted to magnetic fields.

Due to a tweeter's rapid movement, we use ferro-fluid in all our tweeter magnetic gaps to provide mechanical damping, conduct heat away from the voice coil, and improve power

Frequency Response

The frequency response is the measurement of the specific range of frequencies that a speaker is capable of reproducing, expressed in hertz (hz). The average range for human ear response is 20 to 20,000 hz.

A typical frequency response curve plots loudness in dB vs. frequency. This information is helpful because the overall tonal characteristics of a speaker can be determined from this plot. Also, the useful operating range of a speaker can be measured.

If a frequency-response specification does not show a maximum deviation (+/- "x" dB), there is no way to know how consistent the speaker's response is (it might have objectionable peaks & dip), and it is essentially useless.

All our speakers' maximum deviations are equal to or less than


A grille is the screen that covers the front of a speaker to prevent it from getting dusty, and to protect it against accidents.

Despite using acoustically transparent cloth, the grille frame may still cause some negative effects due to diffraction problems, so some audiophiles simply leave it

Hi-Pass, Band-pass, Low-Pass.

These are circuits in a speaker's crossover network that progressively attenuate signals above, between, or below its cutoff frequency, so crossover networks can channel audio frequencies to proper speakers, to attain good audio and safe speaker operation.

  • Hi-pass: A filter that allows high frequencies to pass, but cuts off lower frequencies. Used on tweeters and midranges to limit low frequency production, thus reducing excursion and distortion.
  • Band-pass: A filter that allows segments of the audio frequency spectrum to pass, but cuts off other frequencies. Used on midranges to limit high & low frequency production and to reproduce articulate, dynamic sound.
  • Low pass: A filter that allows low frequencies to pass, while rolling off higher frequencies. A low-pass filter is used on woofers to reduce their output at frequencies where they experience cone breakup or poor off-axis response.

There is no one best filter; it depends on application and intended outcome. Our designers use the filters required to get the optimum performance from the


Expressed in ohms, impedance is a measure of electrical resistance. It is a complex calculation resulting from a combination of resistive, capacitive, and inductive elements in a circuit.

Actual impedance constantly fluctuates. However, speakers are usually given a single nominal impedance rating for easy comparison. We have employed an impedance equalization circuit to keep impedance more stable and low, making it more efficient and resulting in a more accurate/noise free

Impedance Equalization Circuit

The impedance equalization circuit, is simply a capacitor and a resistor in series, parallel with the driver. It is used to counteract the rising impedance of a voice coil caused by inductive reactance.

We have placed impedance equalization circuits after the crossover of every speaker to ensure a smooth impendance curve. top

Litz Wire

A Litz wire is constructed of individual film insulated wires bunched or braided together in a uniform pattern of twists and length of lay.

The multistrand configuration minimizes the power loss otherwise encountered in a solid conductor due to the "skin effect," or the tendency of radio frequency currents to be concentrated at the surface of the conductor. Litz constructions increase the amount of surface area without significantly increasing the size of the conductor.

We have used Litz wires in our crossovers to minimize power losses, and to obtain the highest possible efficiency. top

M-T-M ( D'Appolito )

The M-T-M is a symmetrical vertical configuration in which a tweeter is placed midway between the two midrange drivers ( or two woofers ).

This arrangement is widely adopted in our speakers, as it yields a narrower vertical dispersion that in turn reduces floor and ceiling reflections. A superior vertical symmetry is achieved compared to traditional two-way speakers. top


A medium density fiberboard is a type of engineered wood product that is used extensively for speakers because of its even density, high mass, and good damping ability. A MDF will hold sharp edges and complex forms very well.

All our speaker cabinets construct with rigid, sturdy MDF ( 18mm, 25 mm ) which are applied with various veneers &


Midrange is the segment of the audio frequency spectrum between the bass and treble frequencies. It sometimes refers to a driver designed to reproduce these frequencies.

For years, audio enthusiasts concentrated on the bass and treble frequencies because they were at the edge of the hearing range and were more difficult to reproduce. However, we believe the once-forgotten midrange is one of the most critical areas in speaker performance due to the location of human vocals and many instruments in this area.

This emphasis has been carefully integrated into all our midrange drivers' development. Most of our drivers even come with a phase plug. We have also dedicated our 3D Matrix & Chopin LE series as "music listening" speakers with premium midrange

Neodymium Magnet

Neodymium is a rare metal with extremely powerful magnetic properties. It has the ability to create a magnetic field 10 times stronger than the conventional ferrite magnet.

Our Polar Light & Chopin series have utilized this high efficiency magnet, thus, less material is needed, allowing for a more compact motor structure. These speakers are also inherently video shielded very well, due to the smaller stray magnetic


An octave is a ratio of 2:1 or 1:2 in frequency. For example: one octave above 200 Hz is 400 Hz, and one octave below 200 Hz is 100 Hz.

20Hz-40Hz is often considered the bottom octave. Each octave you add on the bottom requires that your speakers move four times as much air!top

OFC ( Oxygen-Free Copper )

When oxygen is present in the composition of copper, it has a tendency to make the metal much more susceptible to corrosion over time, \which increases the resistance and signal loss in the conductor . It may also reduce the flexibility and strength of the conductor that results in the breakage and destruction of the cable's functions all together.

We have used OFC wires in all the internal wiring between crossovers and drivers in order to prolong cable life and to deliver improved dynamics and unrestricted high frequency

Orders Of Crossovers

In a crossover network, sets of capacitors (high-pass) and inductors (low-pass) are used as filters. The higher the order, the higher the number of components have been used, the smaller the overlap of filtered frequencies (cleaner audio), and the steeper the cutoff rate (less natural sound).

  • First-Order Crossover Network: A crossover network that uses a single component as a filter, yielding a cutoff slope of 6 dB per octave.
  • Second Order Crossover Network: A filter that uses a combination of two components to yield an approximate 12 dB per octave roll-off.
  • Third Order Crossover Network: A filter that uses three components to produce a roughly 18 dB per octave rolloff.

The number of the crossover order does not necessarily reflect the quality of the audio, as it depends on application and intended outcome. Our designers use matching crossover orders to get the optimum performance from the

Passive Crossover

Passive crossovers consist of a combination of capacitors, inductors (coils), and resistors. These direct proper frequencies to appropriate drivers.

Typically built into speakers, they do not require any external power and are performed to the signal at the speaker-level. They are also load dependent (the transition may not be very smooth or accurate if a different speaker is substituted for the one the crossover was designed for).top

Passive Radiator

A passive radiator is an unpowered device that relies on pressure generated within the cabinet to reproduce low frequency signals, and is often constructed like a woofer, without magnets & a voice coil. A passive radiator is used to tune a cabinet to a certain frequency that is controlled by the moving mass of the diaphragm.

We have introduced the passive radiator in our Rose tower speaker and Nature subwoofer in place of a port. By doing this, they receive the benefits of elimination of extremely long ports and port noise, and higher frequencies will not leak out through the

Phase, In Phase, Out Of Phase.

Phase : Refers to the timing relationship of two or more sound waves. A phase can vary anywhere from 0 to 360 degrees and varies with frequency as well.

  • In phase : Two or more signals that have the same waveform and identical amplitude in synchronization.
  • Out of phase(180 degrees) : when the crest and trough of both waves occur at the same time, this will cause a cancellation of the two waves.

It's important that your stereo speakers are playing "in phase," which means the drivers of your speakers are moving in and out at the same time.

If your stereo speakers are "out of phase," that is, with one set of positive and negative leads reversed, you'll hear significantly less bass, and instead of producing a strong center image, the sound tends to stay localized at the

Phase Plug

Due to the shape of the cone driver, the higher frequency sound waves tend to collide at a focal point. This causes phase distortion and a loss in clarity.

The phase plug is a protruded piece that improves driver performance and clarity by deflecting delicate midrange sound waves out into the space and minimizing distortion .

We have phase plugs on most of our larger mid-range & base mid-range drivers. As a result, accuracy and transparency are improved. This also has critical effects on the realism of the sound fields reproduced by high fidelity digital audio and surround sound


Sound waves radiate from a source like a pebble dropped into water, with the expanding wave patterns moving away from impact.

Obviously it is difficult to integrate multiple drivers into a truly coherent expanding wave, but with careful driver engineering and crossover development our speakers are doing quite well in following point-source concepts. top


Polypropylene is a strong, durable synthetic material utilized in speaker cones. It is characterized by light weight, low resistance, and minimum resonance, which are essential for accurate midbass and smooth midrange response.

We have utilized Polypropylene cones in our Rose series speakers to offer the enhanced elasticity necessary to reproduce fast transient

Recommended Amplifier

The recommended amplifier is the amount of electrical power that a speaker can comfortably handle, and reproduce quality sounds for a long period of the time.

It is different from "power handling," which is a measure of how much amplifier power a speaker can take before it is damaged. Although it looks more impressive ( about 50-80 watts higher than recommended amplifier ), it is misleading. We choose not to include it in our specifications in order to prevent abusive

Satellite Speakers

Satellilte speakers are small speakers with limited bass response, and are used in conjunction with a subwoofer to fill in the lower octaves. The advantage of satellites is the ability to use small enclosures. The disadvantage of them is the difficulty of integrating the lower and higher frequencies.

We are not believers of satellite speaker systems. Instead, we are in the process of developing a super-compact high end cabinet speaker system which can reproduce full range sounds in a smaller

Sensitivity ( dB /1m/2.83v )

Sensitivity indicates how well a speaker system converts input power into sound. Usually sensitivity is measured in decibels at a distance of 1 meter from the source with 2.83 volts ( required voltage to deliver 1 watt of power into an 8-ohm load ).

The higher this figure, the louder your speakers will sound with a given amount of amplifier power. It measures the quantity of sound, not the quality.

All our speaker can be catalogued as high sensitivity speakers, which can be driven by a less powerful amplifier. See also


Stereos imply the use of at least two separate channels to provide spatial realism or directional effects and create the illusion of a three-dimensional, holographic image between the speakers and even beyond.

Our 3D Matrix and Chopin series are a great fit for stereo music


A subwoofer is a speaker designed exclusively to reproduce a range of very low frequencies (20-200Hz). It is typically powered by its own amplifier; a separate track is recorded for the subwoofer in home theater.

Our Subwoofers come with various designs ( bass reflex system w/tuned port, bass reflex system w/passive radiator, band-pass system ) to meet the different requirements. They are all continuously adjustable in sound level, phase, and frequency, and offer deep, resounding bass, which are a key part of 5.1-channel surround

Surround Speakers

In a multichannel audio system, surround speakers are positioned to the sides of or behind your listening seat, creating a sense of sonic envelopment or all-around directionality.

Surround speakers help create a wrap-around three-dimensional sound field by reproducing the surround information on video soundtracks and music recordings encoded with surround sound. Depending on the format, the surround speakers will be asked to do different things.

We design 2 way bass reflex system for all the surround speakers to extend bass response and to ensure a full-range reproduction. There are two distinctive type of drivers placement to achieve different surround effects, one for more direct radiation, and one for a more diffuse sound field (bipole).top


Timbre refers to the overall frequency balance of a system. Timbre is what gives a voice or instrument its distinctive tone, even when sounds are at the same pitch and volume. Some speakers will reveal sounds warmer than others, some brighter, etc.

In our surround sound systems, that all speakers have a close timbre match for the highest degree of sonic

Titanium Dome

A titanium dome is a hard dome tweeter built with metal which has exceptionally lightweight and strong properties. The differences in reproduction between hard and soft dome tweeters are present, but very subtle.

The essential difference is in the higher frequencies that are reproduced by a hard dome, up to 25kHz more than a soft dome. We have used titanium dome for our most exquisite speakers : Chopin LE & Polar Light

Transmission Line

A transmission line is a speaker enclosure in which the back wave is forced to travel through a long damped tunnel before being ported to the outside. Therefore, the front and rear waves will add to each other upon exiting the front of the line.

It is very complicated, esoteric, and difficult to build transmission line enclosures. Consequently, we have gone through much trouble to ensure superior bass response and

True Piano Mirror-Finish

Many speaker manufacturers use an inexpensive vinyl finish and name it "piano finish." This plastic material is shiny but it looks nothing like the true, rich mirror- finish that we create. We use 18 meticulous processes & coatings to attain the lavish heirloom grade appearance. It takes weeks to produce each speaker cabinet!

We have no doubt our speakers will enhance any home de`cor. top

Tuned Port

A tune port is an opening in a vented speaker cabinet that "tunes" the cabinet to a certain frequency. The port enables sound waves from the back of the driver(s) to reinforce the sound waves from the front to extend the bass response. In a given box, a longer port corresponds to a lower tuning frequency.

A tuned port's diameter, length, and the way in which it is mounted are crucial, so we have specially engineered ported cabinets to allow higher power handling, higher speaker efficiencies, and improved low frequency performance. top


A tweeter is a driver that is responsible for producing the higher range of frequencies. The typical range is everything above 2,000 Hz or so. Tweeters must be used in conjunction with woofers or woofers & mid-range to form a full-range system.

A tweeter is characterized by its light weight, enabling it to produce the fast vibrations necessary for high frequency reproduction. Therefore, we have carefully chosen silk or titanium domes for our tweeters, to provide the sizzle and sibilance that gives a more life-like sense of music. top

Video Shielding ( Magnetic Shielding )

Video shielding is a way of containing a speaker's stray magnetic field inside its cabinet. Any speaker within two feet of a TV screen should include magnetic shielding to prevent color interference, especially with the center channel speaker which is often placed on the top of a TV. If an unshielded speaker is placed too close to your TV, it can cause picture distortion and may even permanently damage the TV's picture tube.

All our video shielded drivers come with double-shield design : a magnet of the opposite polarity & a ferrous shield . The combination of the second magnet and the metal shield will reduce the stray magnetic field to almost nothing, and it's absolutely safe to put against any electronic

Voice Coil

A voice coil is a coil of wire which is bonded to the diaphragm of a dynamic driver and sits in a magnet. It converts electrical signals into mechanical energy and vibrates the diaphragm to create sound.

The most common cause of speaker damage results from voice coil failure. We have not only used larger and more layered voice coils than ordinary speakers, but have also ferro-fluid cooled all our tweeter's voice coils to prevent the common overheating


A woofer is the driver that is responsible for producing bass or bass/mid-range frequencies. A woofer is characterized by its increased radiating area, increased excursion capabilities, & heavy-duty construction. These increases are necessary for low frequency production.

We have carefully selected and tirelessly tested our woofer cone materials. Our overall favorite is doped wool non-press paper cone, which is widely adopted in our