What is time and phase correct?

Time and phase, in combination with amplitude, determine what we hear.

Sound is comprised of many different frequencies intermingled and combined to form complex waveforms. A speaker is time an phase correct when all the frequencies arrive at the listener's ears aligned in time and phase so that all the complex waveforms are intact.

The woofer, midrange, and tweeter will all reproduce their portions of the frequencies that make up this waveform. If the speaker is time and phase correct the outputs of the three drivers will add together at the listening position into a very close reproduction of the original waveform.

But if the drivers are not properly aligned, or they are not all connected in positive phase, or if a high-order, steep slope crossover is used, the ouputs from the drivers will arrive at the listening position out-of-step from each other and twisted in phase. Now we have a speaker with flat frequency response that cannot accurately recreate the musical waveforms. Believe it or not, this is exactly to case with the vast majority of loudspeakers.

So, why do most mainstream manufacturers and magazines focus only on the amplitude (frequency) response of speakers and ignore the critical time and phase? We believe this tunnel-vision approach is a direct result of a serious flaw that has affected almost every listening test ever done. The flaw is that they are TESTS.

We enjoy music as an emotional experience. We are drawn into good music, exhilarated by exciting music, relaxed by soothing music, and put-off by bad music. In a listening TEST, people put away their emotions and try to use their analytical mind to evaluate a speaker's performance. It's like trying to evaluate the quality of a classic painting by counting how many different colors are in it. The analytical mind focuses only on the surface, the frequency response, and ignores the reason for music; emotion.

Our opinion is that these evaluations made with the analytical mind have nothing to do with a speaker's true performance on music. They are cited in various circles as proof that time alignment doesn't matter, or that phase doesn't matter, or that all wires sound the same, or that all amps and CD players sound the same, but they all miss the fundamental truth. Listening to music is an emotional event and cannot be accurately evaluated by the analytical mind.

Why is it important to have speakers that accurately reproduce the time and phase relationships of the original signal?

A piano and a violin can play identical notes with identical fundamental frequencies. They produce different sounds because each instrument has unique timbre. 

Every musical note consists of a fundamental tone and a unique set of harmonic overtones that provide timbre (musical color or signature), allowing us to identify the instrument or voice. Accurate reproduction of timbre and the correct placement of instruments and voices within an acoustic image require that the amplitude and timing relationships between the various parts of each note be maintained. All components in the recording chain and all playback components except speakers maintain these amplitude and phase relationships. 

Time- and phase-accurate speakers with flat amplitude response assure that the entire waveform is preserved. When the output waveform is a replica of the input waveform, all amplitude and timing relationships are maintained. When some parts of the reproduced signal are out-of-phase timbre and imaging are altered.

Why do you recommend that Vandersteen subwoofers be placed in a corner?

Subwoofers, like all audio components, should be used as they were designed to be used. This requires some additional explanation. 

Subwoofers designed with relatively high “Q” may sound boomy when positioned in a corner. Subwoofers designed with low “Q” may require corner placement in order to provide flat bass response. Vandersteen subwoofers have adjustable “Q” to allow versatility of placement.

What is the purpose of the “Q” control on Vandersteen subwoofers?

With the “Q” at low settings, the most controlled bass and the best interface with the room will be achieved by corner placement. Setting the “Q” control to higher numbers will allow placement in other room positions without the impression of diminished output. Higher settings will also help to compensate for rooms with poor support for bass frequencies.

How does the 2Wq subwoofer differ from the V2W?

The 2Wq subwoofer provides the best bass definition with the least overhang possible. It has many unique features, including three small slot-loaded drivers with indirect radiation, making it the best subwoofer available for music reproduction. While the 2Wq is virtually “overload proof” it may provide insufficient mid-bass emphasis for exaggerated film sound effects. 

The V2W is optimized for movie sound effects. It has a large direct-radiating passive radiator. This allows for increased volume at mid-bass frequencies with some small sacrifices in bass definition and control. The V2W also has a high-level input allowing it to be connected to the LFE output of a surround sound processor.

Why do Vandersteen speakers perform best when positioned away from the room boundaries?

All speakers, even “bookshelf” designs will sound more open and spacious when positioned away from room boundaries. Careful attention to the problems of energy storage and reflection are an integral part of Vandersteen speaker designs. Reflections from the walls can create time smear that the baffleless enclosures of most Vandersteen speakers were designed to eliminate.

Can Vandersteen speakers be used against the wall?

Models 2 and 3 have rear-facing bass elements and should be positioned at least a foot away from a wall. Vandersteen makes several models, including the VSM, VLR and VCC series, which are designed to be mounted on or placed near a wall.

Why do many Vandersteen models have simple cloth-wrapped enclosures?

Vandersteen Audio has always aspired to a simply goal: that owners should incur no expense that doesn’t provide them with better sound. Vandersteen uses the finest available internal components to deliver state-of-the-art audio performance. Furniture-grade cabinetry could potentially double the price while providing no audible improvement.

I’ve heard that first-order speakers have limited dynamic range and higher distortion. Is this true of Vandersteen speakers?

Some compromises must be accepted with 2-way first-order designs. Vandersteen was able to overcome the assumed limitations of first-order speaker systems, while providing accuracy that speakers with steep-slope crossover networks cannot equal, by developing 4-way designs utilizing unique drive elements with unusually wide bandwidth. The Model 5 and Quatro systems further advance dynamic range capability, and reduce distortion, with built-in amplified subwoofers.

Aren’t coaxial drivers inherently time and phase correct?

Actually most are not. Temporal alignment of the drivers is only one aspect of waveform preservation. Phase shift is caused primarily by the crossover network and varies with frequency. You can’t “time align” a speaker with third- or fourth-order networks because phase is constantly changing.

Aren’t planar speakers time- and phase-accurate?

Actually most are not. Almost all planar speakers have a woofer and a tweeter with a crossover network to blend them together. A speaker with a steep crossover slope is not time and phase-accurate. Even if the crossover network is first-order (most aren’t), planar speakers often have the tweeter positioned beside the woofer. The relative path length between these drivers and each listener will be different for every lateral listening position.

Why do 2Wq subwoofers connect to the speaker level signal rather than the line level signal like other subwoofers?

The Vandersteen subwoofer interface is unique. A first-order, passive high-pass filter is placed in front of the main amplifier. The subwoofer samples the output from the filtered main amplifier and corrects for the roll-off that has been introduced. This is the only way to provide a true, first-order blend between the subwoofer and the main speakers that is transparent and seamless.

A passive high-pass filter is as transparent as the input coupling capacitor that is probably present in the amplifier already and may actually improve the sound of direct-coupled amplifiers that use servo circuits instead. Sampling the output of the main amplifier passes along to the subwoofer the sound and propagation speed of the amplifier that drives the main speakers for a seamless blend between the two.

For additional explanation read the Audio Perfectionist review of the 2Wq.  You can find it in the Reviews section of our website.

What is a good loudspeaker supposed to do?

A loudspeaker takes the place in the room of what it is reproducing, be it a piano, a vocalist, an orchestra, or a spectacular sound effect. To be good, it must accurately reproduce in time, in phase, and in amplitude, the signal passed on to it from the amplifier.

It should have low distortion, but it should not focus on reducing one type of distortion at the expense of others. Similarly, it should be a balanced design with attention paid to time, phase, and amplitude.

It should be built of high-quality components that reveal the most musical truth in live vs. reproduced tests. The components should be engineered for maximum reliability and consistency.

It should be full-range. Bass is the foundation of music and conveys much of the emotion. Without bass, there is no music.

What drivers does Vandersteen Audio use? Are they exotic?

We design the drivers used in Vandersteen loudspeakers for the particular needs of each speaker model. Some drivers are assembled with industry-standard, high-quality components while others have our proprietary baskets, cones, spiders, and/or surrounds. With our limited production requirements, it is not practical for us to invest in expensive driver manufacturing equipment just to bolster our pride without providing any true benefit to our customers. To insure maximum quality and efficiency, we ship our exclusive components to renowned driver manufacturing specialists where they are incorporated into drivers made to our exact specifications.

Our drivers use a variety of cone materials, all chosen for their suitability to a specific driver rather than fleeting appeal as the latest exotic material. Every driver must pass our live vs. reproduced evaluations. Cone materials that excel in one application may not be appropriate for another. For example, aluminum, Kevlar, and carbon fiber are very good for subwoofer cones and tweeter domes where they remain in the piston mode through the pass band and the inherent nasty peak from their first break-up mode is either way out of the pass band (subwoofer) or above audibility (tweeter). Woofers and midrange cones however, need a neutral material with high internal dampening like treated paper since their first break-up mode will be in or near the pass band. Since it is very difficult to control the initial quality of treated paper cones and to maintain the quality over time, we use proprietary or selected mineral filled polypropylene cones in these critical applications. These unique cones combine the superior neutrality and dampening characteristics of treated paper with the consistency and precision of injection molding.

How about those new room/speaker electronic interface boxes that promise incredibly flat response through room correction?

This is an interesting concept. Add an equalization box to the system that changes the response of the speakers so that they zig where the room zags. Instant flat response!

Things are never as simple as they seem. We humans are very good at differentiating between the source of sound and the effect of a room. Put your best friend in 10 different rooms with very different sonic characteristics and he or she will still always sound like your best friend. No matter how bad the room acoustics, they will not become a different person. This is because the mind gives preference to the source (direct) sound and partially or totally disregards the effects of the room.

But, modify the tone of your friend's voice to counter the room effects, and now you have a new best friend. The mind still locks onto the source and the source doesn't sound like your friend. The same thing happens to a violin, a piano, a quartet, or an orchestra. Modify the tone for flat response in the room, and the accuracy and realism is lost. You make the source sound inaccurate and the source is what we hear.

So why is there a positive reaction to these boxes in the market place?

Because even though they screw-up the overall sound, they do have one social redeeming value. At the lower frequencies where wave lengths are long and the direct sound and room effects are homogeneous, (Below about 150Hz) humans cannot differentiate between the source and the room effects. Equalizing these bass frequencies for flat response can provide very positive benefits. And since these low frequencies form the musical foundation and are critical to conveying the music's emotion, some people may consider the benefits there more than the the negative effects through the midrange and treble.

Our view is that this technology should only be used below 150Hz where the results are purely positive. It should never be applied to the midrange or treble or even be in the signal path. This is how the technology should be used and how it is used in the Vandersteen Model Five Loudspeaker.

Will a low-power tube amplifier drive Vandersteen speakers?

Maybe, there are too many variables to give a definitive yes or no.

Vandersteen full-range speakers all have very stable input impedances and are very easy for tube amps to drive. That leaves available power, room size, and your listening habits and volume expectations as the deciding factors.

Why do Vandersteen floor-standing speakers sound different when I stand-up?

A vertical set of drivers in a time and phase correct speaker has to be aligned for a specific listening height. Vandersteen floor-standing speakers have a six-inch high alignment window that is centered on the ear height of an average person seated on a fairly low couch. To accommodate higher seating positions, the speakers can be tilted back to raise the alignment window as needed.

When the speakers are set-up for seated listening, standing-up obviously takes your ears out of the alignment window. The sonic change you hear is the difference between a speaker that is time and phase correct and one that is not. Only if time and phase were irrelevant, would there be no difference.

What is bi-wiring and what are the advantages?

Bi-wiring uses two separate sets of speaker cables to connect a single pair of loudspeakers to an amplifier. Coupled with a crossover designed specifically for bi-wiring, it offers many of the advantages of bi-amplifying the speakers with two separate amplifiers without the cost and complexity of two amplifiers.

We began experimenting with bi-wiring back in the early '80s, an era when horizontal bi-amplification was considered the ultimate way to drive quality loudspeakers. (Horizontal bi-amplification used one amplifier to drive the low-frequency section of a speaker and a second amplifier to drive the high-frequency section.) We noted that speakers sounded better when bi-amplified by two amplifiers than when driven by a single amplifier. Surprisingly, this superior performance was evident even when the speakers were bi-amplified by two identical amplifiers at a low volume level and the amplifiers were each driven full-range without an electronic crossover. We initially believed that the double power supplies and other components of two amplifiers were responsible for the improvement, however building amplifiers with twice the power supply and doubling-up on other critical components failed to provide the bi-amplification benefit.

So we looked at the speaker wires. With two amplifiers, bi-amplification used two sets of speaker cables so we experimented with doubling-up the speaker wires and with larger wire. Neither duplicated the bi-amplification improvements. Then we considered that in a bi-amplified system, one set of wires carries the low-frequencies and the other set of wires carries the high-frequencies. We modified a speaker's crossovers to accept two sets of cables and present different load characteristics to each set so that the low-frequencies would be carried by one set of wires and the high-frequencies by the other set of wires. Finally we heard the sonic improvements of bi-amplification with a single amplifier.

Additional experiments with a Hall Effect probe revealed that high-current bass frequencies created a measurable field around the wires that expanded and collapsed with the signal. We believe that this dynamic field modulates the smaller signals, especially the very low level treble frequencies. With the high-current signal (Bass) separated from the low-current signal (Treble) this small signal modulation was eliminated as long as the cables were separated by at least an inch or two. (To keep the treble cable out of the field surrounding the bass cable.)

The crossovers in Vandersteen bi-wirable speakers are engineered with completely separate high-pass and low-pass sections. The bass inputs pass low-frequencies to the woofers, but become more and more resistive at higher frequencies. The treble inputs pass high-frequencies to the midrange and tweeter, but become more and more resistive at low-frequencies. The output from the amplifier always takes the path of least resistance so deep bass frequencies go to the bass input (Low impedance at low-frequencies) rather than to the treble inputs (High impedance at low frequencies). For the same reason, treble frequencies go to the treble input (Low impedance at high-frequencies) rather than to the bass inputs (High impedance at high-frequencies). At the actual crossover frequency, the output from the amplifier would be divided equally between the two inputs as they would both have the same impedance at that frequency. Because of the different reflected impedances of the cables, the crossover between the woofer and midrange actually occurs at the wire ends where they connect to the amplifier.

The benefits of bi-wiring are most obvious in the midrange and treble. The low-current signal to the midrange and tweeter drivers does not have to travel on the same wire as the high-current woofer signal. The field fluctuations and signal regeneration of the high-current low-frequencies are prevented from distorting or masking the low-current high-frequencies. The back EMF (Electro-Mechanical Force) from the large woofer cannot affect the small-signal upper frequencies since they do not share the same wires.

The effects of bi-wiring are not subtle. The improvements are large enough that a bi-wire set of moderately priced cable will usually sound better than a single run of more expensive cable.

All the cables in a bi-wire set must be the same. There is often great temptation to use a wire known for good bass response on the woofer inputs and a different wire known for good treble response on the midrange/tweeter inputs. This will cause the different sonic characteristics of the two wires in the middle frequencies to interfere with the proper blending of the woofer and midrange driver through the crossover point. The consistency of the sound will be severely affected as the different sounding woofer and midrange drivers conflict with each other in the frequency range where our ears are most sensitive to sonic anomalies. The disappointing result is a vague image, a lack of transparency through the midrange and lower treble and a loss of detail and clarity.

Some of the benefits of bi-wiring are from the physical separation of the high-current bass and low-current midrange/tweeter wires. So-called bi-wire cables that combine the wires in one sheath do not offer the full advantages of true bi-wiring although they may be an excellent choice for mono-wiring the speakers.

The cables should all be the same length. This is not due to the time that the signal takes to travel through a cable, but rather that two different lengths of the same cable will sound different. If the cables connecting one speaker are a different length than the cables connecting the other speaker, the resulting difference in sound between the two speakers will compromise the imaging and coherence of the system. If different lengths of cable are used for the bass and midrange/tweeter inputs of the speakers, the effects will be similar to those experienced when using two different cables as described above.

Since short runs of speaker cable sound better than long runs, consider placing your electronics between the speakers rather than off to one side. If for convenience or aesthetic considerations, the electronics must be located a considerable distance from the speakers, it is usually preferable to place the amplifier between the speakers and use long interconnect cables and short speaker wire.

What wire should I use?

With all the advancements in materials and construction, there are good wires available at a wide range of prices. We receive at least one call a day asking what wire to use with Vandersteen speakers. Often the callers want to know what wires were used in designing the speakers or what the internal wires are.

Actually, neither the design wire nor the internal wire has any bearing on choosing the wire that is best for your system. During design, we connect the loudspeakers with a resistively loaded bus bar that can be set to simulate different wire lengths without contributing any inherent sonic character of its own to the sound. None of the internal wires in a Vandersteen speaker carry a full-range signal, so they are each individually engineered as part of a tuned-loop with the driver and crossover they connect. The woofer, midrange, and tweeter each use different wires selected for their characteristics coupling the particular driver to the crossover. If any of the wires were changed, the relationship between the crossover and the driver that wire connected would have to be adjusted.

There is a best wire for your system. It is the wire with the sonic characteristics that work best with your electronics, your speakers. your listening room, and your personal listening tastes. Change any of the four determining factors, and the best wire may also change.

This is why it would be irresponsible for us to suggest a wire to use. We know the speakers and might know the electronics, but there is no way we can experience your room or adequately understand your personal listening tastes to make a valid recommendation.

What we can recommend, is that you work with your local dealer to find the best wire for your system. Start with a base wire, then borrow different wires and evaluate them with your music, in your own system, in your own room. You don't have to try every wire, just enough to find one that works well in your system.

Why is it so difficult for subwoofers to blend into a system?

There are two primary reasons that most systems do not achieve a linear and seamless transition between the main speakers and the subwoofers.

Conventional powered subwoofers receive their input signal directly from their crossover before the main amplifier. The sonic signature of the main amplifier that is an important part of the sound you hear from the full-range speakers is missing from the subwoofer. This causes blending and integration problems as the sonic characteristics of the system are different above and below the subwoofer crossover point. This deterioration of system coherence is why conventional subwoofers have never been totally accepted as part of ultra high-performance audio systems.

The Vandersteen Model 2W Powered Subwoofer uses a unique connection method that leaves the main amplifier in the electronic chain to the subwoofer as well as the main speakers.

The second reason for a poor blend is that the main speakers do not have the bass extension necessary for a linear transition. Basic filter theory dictates that the main speakers must have predictable response at least an octave below the crossover point to insure proper blending with the subwoofers. For an 80Hz subwoofer crossover point, the main speakers must have predictable response to 40Hz or lower. This is why it is difficult to successfully mate subwoofers with mini-speakers - the limited-range small speakers simply cannot reach the required full octave below any reasonable subwoofer crossover point.

The Vandersteen 2Wq subwoofer and V2W Video Subwoofer both have unique tailoring capabilities that can significantly improve the transition to limited-range mini speakers. The 2Wq's adjustable Q and the V2W's adjustable phase can contribute to a better subwoofer to mini speaker blend than is possible with a conventional subwoofer. Factor in the superior detail and pitch control of the three quick 8-inch drivers, (compared to slow big woofers) and the Vandersteen subwoofers are clearly the best match with small speakers.

Why doesn't Vandersteen offer a larger subwoofer?

We have experimented for several years with larger subwoofer designs that would theoretically offer superior performance to our current subwoofers. In all cases , multiple 2Wqs and/or V2Ws out-performed the larger, more expensive designs for less money. For a given amount of bass energy, injecting the low frequencies into the room at multiple locations gives a more visceral and linear bass response.

What's the low-down on toeing-in Vandersteen speakers?

Several things affect the degree of toe-in a pair of speakers requires to produce a stable and precise image. The width of the baffles holding the drivers, the location of the speaker's own reflective surfaces, and the location of reflective surfaces in the room are all factors. Any sonic reflection from a large speaker baffle is 100% distortion and changing the angle of the reflection relative to the listening position will change the system's frequency response and sound.  The Vandersteen minimum baffle design effectively eliminates baffle and other structure based reflections leaving room surface reflections as the only toe-in factor. If the side walls are within 4 feet of the speakers, toeing-in the speakers can improve the image. When the speakers are toed-in, they should never be pointed directly at the listener.

What is the difference between 2Ce & 2Ce Signature?

The 2Ce Signature’s advancements include:

  • Barrier strip bi-wire inputs for the optimum cable to speaker interface.
  • Cables need spade lug connectors with a maximum width of 7/16 inch.
  • Upgraded crossover components.
  • More sophisticated crossover technology with enhanced design and layout.
  • Upgraded tweeter. (The one used in the Model 3A.)
  • Improved coupling and transition between the woofer and the active acoustic coupler.

The 2Ce Signature is more transparent and conveys spatial information better than any previous Model 2 series loudspeaker. The low frequencies are tighter and more detailed. The highs are cleaner and lower in distortion. With the addition of the 2Ce Signature, the Model 2 series reaches a new pinnacle of performance and musicality.

What is the difference between 3A & 3A Signature?

The application and integration of advanced Vandersteen Model Five technology and components set the 3A Signature apart from the standard Model 3A. The 3A Signature features Model Five grade crossover components and hand-tuned compensation networks that improve the speaker's linearity and phase accuracy.

The tweeter in the 3A Signature is the same type used in the Model Five and contributes to the speaker's improved definition and transparency. Like other Vandersteen Signature models, all the drivers are hand selected after extensive testing and carefully matched to each other. The enhanced stability of the image and soundstage is obvious on high-quality recordings.

Listening to 3A Signatures is an enlightening experience. Sounding more like Model Fives than Model 3As, the 3A Signatures reveal inner details of music and movies with incredible clarity. They reproduce the nuances, background sounds, and minute effects that convey the essence and emotion of the music or movie.

Richard Vandersteen's signature on the input plate is a reminder that the 3A Signature is the best Vandersteen Model 3 series loudspeaker ever built.