"Zd, to say that engineering expertise and technical resources is irrelevant is an extreme statement. If high fidelity sound reproduction is the goal, then the manufacturer and the consumer just can't be that far apart."
If that's what you think I meant, I didn't do a good job explaining my point. If I read your post correctly, you said its always beneficial and important for the customer to be as close to the level of the designers technical ability as possible. While it can't hurt, I just don't think its necessary to achieve the best possible results. All designers have a different idea as to what good sound is. That applies to the consumer as well. No one is more capable of building your system than you. Your own technical ability won't have an effect how much you like your system. Listening is the dominate factor. Its no different than saying a race car mechanic needs to be a race car driver himself, or an aircraft engineer has to be able to fly the F-16 he's helping build.
"From an engineering perspective how does R. Vandersteen justify the powered woofers in his upmarket loudspeakers?"
He doesn't have to. He would have to do more explaining if he didn't power his subs. The vast majority of sub's, both internal and stand alone, are powered. Its an industry standard practice. It gives the buyer more options, not less. Powering the bass speaker on something like a Model 5, allows for a much broader range of amp options. A lot of people use low powered tube amps on their 5's. Chances are, those amps wouldn't be a realistic option otherwise.
" Wouldn't the same rationale apply to the midrange and treble drivers?"
It depends on how you look at it, but I would say no. The application is different. Almost all of the musical detail is in the mids and highs. Low frequencies just don't have the same level of resolution. Think about what you go through when setting up a system. To dial in the bass, the main adjustment is to move the speakers around the room until you find the best spot. Mids and highs are different. Things like toe in, back tilt and specific areas of the room, like the first reflection, need to be dealt with. (I understand that there are other factors involved, and maybe even some overlap. Its just not practical to go over every single detail on a forum like this.
"From a marketing perspective it could be sales suicide since audiophiles basically reject fully powered loudspeaker systems. I'm just saying that the rejection is not based upon sound quality, but upon the perceived lack of upgradeability."
That may be the case sometimes, but not always. For he most part, its about sound quality. Your case will apply to people that shortcut the evaluation process. Buying from reviews, no demo..., and other similar short cuts. Others will put the time in to listen and evaluate before making a purchase. In my own experience, I've put many modest component systems next to expensive, active speaker systems, and was able to get much better SQ from the budget system.
