I've been watching this thread with interest, and after prodding from Chris I am going to address as many of the issues as I can, in one missive. Forgive me if I ramble too much!
First to address the issue of designing not only a $200 speaker but also an $89, after a $60,000 speaker. It's not marketing speak. I had full control of the design and voicing of these speakers, and it was actually a very interesting challenge.
When designing a flagship speaker, of course it's fun as an engineer to work almost unconstrained and to be allowed to explore all sorts of options, advanced materials, large budgets etc. The result should be at the very least excellent, at best unsurpassed.
What however, is the attraction to designing such a low cost speaker?
Well, it's still an interesting challenge, partly because there is so little product out there at these prices that appears to have had much thought put into the sound quality. Marketing and visual design trump sound. But why does this have to be the case?
That was the driving force behind these speakers. With little money to spend, with no advanced materials possible, what are the limits and possibilities?
The challenge becomes examining every single aspect of the design and engineering process and looking where performance can be optimised at no increased cost (cone shape and surround profile, for example) and where one cost can be traded for another.
How important is a film cap, how audible is a ferrite core inductor compared to a laminated core, how much flux can I drag out of a particular size magnet with the right design of pole pice and top plate and back plate. How do I trade voice coil length and top plate thickness for excursion. How do I save money to spend on a curve sided cabinet. Can I afford an RF pressed curved side panel rather than an inferior kerf cut panel.???
There are many more examples.
Then comes the issue of voicing. How resolving is the speaker. Should resolution over-ride bandwidth. How will this speaker be used. What will it be paired with. what kind of bass balance. Should it leap of the shelf in the store with a forward "impressive" sound, or be more neutral and relaxing for more satisfying long term enjoyment.??
As you can see, there are so many avenues to explore in the design, why shouldn't it be just as interesting a project as when designing a flagship.
Of course, if I'd failed in my objectives, and my name was still on it, I'd have changed my name by now!!
And just so you know, I've changed my signature on my credit cards and check book, just to be safe......
Of course, these are not going to be the best out there, but they are I hope, incredible value, and set new standards at the price points.
It is very unusual to be able to incorporate curved sided cabinets, 1" soft dome tweeters, woofers with real size magnets, six element crossovers etc in a product like this. At times I look back on this project and am just as amazed as some of you.
Of course, although I cannot go into detailing about pricing, and relative value between different speakers, manufacturing costs and selling quantities play a significant role, as Kal alluded to. It is rare that in a range of product there is a linear relationship between parts cost and selling price. Expected sales volume of each model has to be balanced against development costs, parts costs, distribution costs etc. This is the real world of manufacturing as opposed to hobbyist building!
Now to some specific issues.
There has been some confusion between different speakers shown at CEDIA and in the blogs. The speakers I have designed here are the BS21, C21, FS51, for BB, and the BS41, along with the sub.
The other series are very different in componentry and price, and are from a different series and origin entirely.
As for "A vertical tube feeding out the bottom sucks away standing waves." this is misquoted. There is a vertical tube inside the speaker. It acts much like a quarter wave stub in antenna design. At the frequency of the main standing wave within the cabinet, it is tuned, by means of its length, internal absorption and location within the cabinet, to short circuit the standing wave and virtually eliminate it. Very neat trick!
Now, as for the center channel speaker, yes it can be used vertically, and in fact would work even better this way. It's an unfortunate fact of home life that center channels are required to be wide and low in shape, forcing typically dual woofers and a central tweeter. This is not a great arrangement for good horizontal dispersion. I have done my best by designing a waveguide around the tweeter to match its directivity to the bass driver, and have set a low xover frequency compared to what is typical for this class of speaker.
It's dual woofers have been optimized for greater mid bass power handling when used along with a subwoofer, for home theater use, as opposed to bass extension for a reasonable full range stereo speaker as was the goal for the bookshelves.
All said, go ahead and use two center speakers vertically.
Regarding the grille design, this is a matter of taste. We did do a survey, and found that the design was liked, but of course we won't please everyone. It does however have some sound advantages. Minimal diffraction of the sound wave, acoustically quite transparent, and a very strong barrier to the drivers. You won't find your tweeter domes and woofer dustcaps pushed in, either at store level (I'm convinced half the time it's from rival manufacturers.;-) ) or at home.
The grilles can be removed with a lot of effort, but I would suggest you leave them in place. You won't gain much by removing them.
Now, the height of the towers. Everything comes at a cost. As Chris said, I had to be reigned in constantly to not overspend. With great height comes great..cost. Cost but little sonic benefit. Another area where I had to make choices. Same with the vents.flared on the outside but not on the inside. Slightly more chuffing at extreme levels, but that cost saving went elsewhere, to greater benefit.
Sensitivity is lower than some of the competitors, except that it is an honestly quoted spec, as is the impedance. Lower sensitivity allows me to design for decent bass extension. With a typical receiver or two channel amp, you won't have too much trouble driving to respectable levels. Head-banging levels? You'd have to be the judge of that, but they are only $89!!
OK, so lots of words. Now I know why Kal gets paid so much for writing.it's tough!
Go listen, judge for yourself. If you like what you hear, I'm happy.