Active speaker, the future? or another fad?

Exertfluffer, you and I are not in disagreement. What you are talking about would allow the flexibility of tailoring the sound to the listener. Again, that is a major goal of mine.

However, as has been pointed out by Phlanoue and Gregm, this is far from a new proposal. I would make sure any company trying to sell you otherwise acknowledges this, or I would start asking questions about them.

In a perfect world, such a speaker should in fact be cheaper, as the company can walk away from the expense of a crossover(this is where I will cede to a manufacturer carping about design costs). You just basically hardwire the drivers to your power amps. Of course, this is high end audio, and when it is all said and done, I would predict we'll end up paying more for this.

I think Vandersteen has been pretty successful selling their 5 series speakers and they're active. FWIW, the 5A's have blown me away and blown the Revel Salon's I've heard.

Ok I have one more thing to add on the idea of "simply swaping an active for a stock passive crossover" in a speaker...I seem to remember having not only talked with manufactures but actually been to speaker manufacturing facilities/plants, where I saw first hand that the crossovers(passive of course) where tweaked to help "tailor the sound" quite a bit! Where there were peaks and dips and "anomolies" between the drivers/enclosure/whatever, the manufactures often "design in" the changes in the crossover to "compensate" for those imperfections or anomolies to make the sound, well, sound right!
Dunlavy audio, for one, used to hand tweak all their custom made in-house crossovers to match each specific speaker! I sat there and watched their engineer(s) adjust cappacitors and resistors(whatever, I'm not a mechanical/electical engineer) to comensate for "less than ideal conditions" or responses in the speaker USING THE CROSSOVER! This is how they got everything to "measure right"! Now, maybe this was a "quality control" or "consistency issue" among the drivers they were using, I don't know.
Still, I went to Infinity's plant, as well as P.B.N's shop, and have talked with makers from Sonus Faber/Summiko, Martin Logan, and others. And I'm under the impression that the "artform of building crossovers" to make the sound "right" is what they all work hard on! You take the crossover out of the equation, then swap something else, I'm wondering how good of a sound you can likely expect, in regards to tonality, balance, phase, peaks, anomilies, etc...you get what I'm saying?
Maybe it would be best to sellect a passive speaker who's crossover network is "the simplest"...first order crossovers, with modest slopes, etc. Hummmm
Anyway, any input here?...or am I just making this difficult. I REALLY WANT TO FIND OUT MORE HERE, AND DO SOME "CUSTOM ACTIVE TINKERING" here! The thing is, before I start tearing appart my speakers and changing things again, I just want some more feedback from others who've touched bass on this "change in dirrection" from the original thread.
What do ya think guy's?.....

Exert - the trick in bi(multi) amping is to know what the designer has done in the passive x-over. Not easy, I know. I wonder if Mr Thiel would give suggestions re, going active in the bass (if s/one were serious about this of course).

The point is, a line-level x-over is fed low level signals, and is much more stable in its filtering action (and often, cheaper). Also, an amp connected to the voice-coil (or nearly) is a much more efficient way of using amp power.

One of the problems with passive x-overs is they perform differently given the power fed to them (which is high), influencing the amps, the frequencies, creating magnetic fields, etc, etc, ad nauseam. If you get it right with a 1kHz sine wave at 1W, it won't necessarily sound "right" with music (multiple waves) at say 8W, etc.

Hence acoustic tests to fine-tune a spkr through the x-over

The bass is a very good first target for discrete amplification. There, all that's needed is usually the x-over frequency & slope; you'd also check for baffles step compensation and any other trick in the x-over (there won't be many). These points are easily addressed with an active filter (yr typical Behringer allows a choice of different slopes, frequncies of course, time delay, transform functions, frequency boost or attenuation etc). If the spkr manufacturer helps with info, it should be possible to get good results (probably better than the original passive) with more, but less expensive amps, by keeping the mid-high x-over as is passive, (one amp, low-medium wattage) and pulling out and biamping the bass region (higher wattage).

People like Nuddel (Genesis sp?) have been offering this, at a price!

Gregm, why whould you go through the trouble of dissasembling a speaker, bypassing the crossover for the bass woofers, AND NOT MAKE THE UPPER MID/TWEET DRIVER(S) ACTIVE AS WELL!!!? This doesn't make sense. Yes, I can see the advantage of actively driving the bass w/electronic outboard crossover/amp combo. But, if you're going to do that, why not make the whole freakin speaker active, and use one outboard electronic crossover?! This makes more sense. Unless however, like I mentioned earlier you start running into problems in frequency response and such from the mid/tweeter by "ditching the stock passive". In that case, I understand leaving things "as is".