Answers as promised; with input from Roger ~
The direction of the sound you hear from a speaker system is determined by the location of the surface from which the sound emanates. A typical, wide-dispersion speaker radiates its sound out into the room where it bounces off various walls and objects in the room.
You hear these reflections as well as the sound from the speaker. This is especially true of the very strong the reflection off the wall near the outside edges of the speakers. Therefore, when listening to wide dispersion speakers, it is common for the sound and image to appear to be wider than the spacing between the speakers because you are actually hearing the sound coming off the walls beside the speakers.
In a narrow dispersion speaker, there are no room reflections -- at least none that are significant enough to affect the speaker's image. So you hear the sound coming directly from the speakers. Therefore, the width of image will be defined by the space between the speakers. A truly holographic, 3-dimensional image will appear to float in space between the speakers.
If you want a wider image, simply place the speakers more widely apart. Note that narrow dispersion speakers can be placed as widely as you wish without developing that dreaded "hole in the middle" of the sound that you get from wide dispersion speakers.
Because reflected sounds ("room acoustics") degrade the sound coming from the speakers, any speaker that generates an image beyond the outside edges of the speakers will produce a less-than-perfect image. The speaker needs to confine the image to the space between the speakers for best performance. For a discussion of this problem in detail, please read Roger's white paper on the subject at Dispersion White Paper
DIFFERENCES IN SPEAKERS BETWEEN INNERSOUND AND SANDERS:
There are certain fundamental design parameters that have found to work best for all types of speakers. Therefore, all speaker types will have certain features that are similar.
For example, most magnetic speakers consist of a cone-shaped woofer, a dome-shaped tweeter, passive crossovers, and sealed box enclosures. Although most speakers are made in this format, they all have various subtle differences in this basic package of design features that make each manufacturer's offerings somewhat different in sound quality and performance.
Electrostatic hybrid speakers are no different in this regard. They are all vertical line sources, with an electrostatic panel on top of the woofer, so they all appear to be similar. But there are a great many detail differences within this basic layout. Like magnetic speakers, these differences can make a lot of difference in the sound and performance of speakers that appear superficially to be quite similar.
In the case of Innersound speakers compared to Sanders speakers, there are major improvements in the power handling and output of the woofer, the electrostatic panel is now utterly reliable and will play at ear-bleeding levels with multi-thousand watt amplifiers, the speaker is modular in construction (no more truck shipping), the styling is improved, real wood is used, digital electronic crossovers are available, the crossover point is lower, the crossover slopes are steeper, electronic time-alignment is used for the first time, all aspects of the system are user-adjustable, the speakers come with redesigned and more powerful amplifiers, certain internal resonances have been eliminated, woofer cabinet internal design has been improved, lifetime warranties are standard, factory support is vastly improved, and the price is lower. So it is fair to say that the Sanders speakers are quite a lot improved and different from Innersound speakers.
Here is a very brief review of the key elements of the Innersound/Sanders history: Innersound, Inc. was founded in 1996 by Raj Varma who lived in the U.K. He hired Roger Sanders to design electrostatic speakers for him. Eventually, Mr. Varma expanded Roger's role to run Innersound in the U.S. while Mr. Varma manufactured computers in the U.K.
The key element here is that Roger was an employee of Innersound and never owned or controlled the company. So when Gary Leeds wanted to buy Innersound, the decision to sell was made by Mr. Varma -- Roger had no say in the matter.
When Gary Leeds bought Innersound, Inc. (February 2003), he dissolved the company and started a new one (Innersound LLC). He allowed Roger to become a minority share holder in the new company.
But as majority share holder, Mr. Leeds maintained total control of the company and once again, Roger could not manage the company in the manner he would have liked. This eventually led to Roger leaving Innersound, LLC in July of 2004.
After leaving Innersound, Roger started his own company (Sanders Sound Systems, LLC). Shortly thereafter, Innersound, LLC went out of business.
But before doing so, Mr. Leeds asked Roger to take care of Innersound's customers. Roger agreed to do so and Mr. Leeds transferred critical Innersound parts inventory to Roger so that he could service Innersound's products.
Note that although Roger does provide service for Innersound's products, Innersound's warranty is no longer valid since Innersound is out of business. In any case, enough time has passed that any warranty on Innersound's products has expired. Therefore, Innersound customers have to pay a modest price to have their equipment serviced by Sanders Sound Systems.
In summary, there have been three distinct companies. There was the original Innersound, Inc., which was owned by Raj Varma. Gary Leeds bought Innersound, Inc., dissolved it, and started a new company called Innersound, LLC. He eventually dissolved that as well.
Roger Sanders started Sanders Sound Systems, LLC. Although Roger worked for both of the Innersound companies, his company (Sanders Sound Systems) is not associated with either of the Innersound companies, both of whom no longer exist.
By having control if his own company, Roger can now operate it as he deems best. For example, he can now offer lifetime warranties and risk-free, 30-day, in-home trials. He also sells both factory direct and through selected dealers.
He makes all the engineering decisions based on performance, instead of on the approval of company owners. And he makes improvements in the design of his equipment when he wishes as technology advances.
Unlike the Innersound companies, Roger handles Sanders' company finances so that there is zero debt, there is cash in the bank, inventory in stock, and overhead costs are extremely low. As a result, Sanders Sound Systems can handle difficult economic times easily, successfully, and with greater security than his larger competitors.
While the Innersound companies could not have survived the current economic recession, sales and income for Sanders Sound Systems have been growing during this time. This is proof that the Sanders' business model is successful. The future of Sanders Sound Systems is secure.