Any thoughts on passive v. active speakers?

Hi Ralph,
Please refer to these pages, you will find more than a few active loudspeakers which can do 20hz and below in the most conservative sense:

https://pmc-speakers.com/products/consumer/se-series
http://www.atcloudspeakers.co.uk/hi-fi/loudspeakers/tower-series/scm20aslt/

BTW, doing 20hz is not always the most important criteria IMO, for that matter many loudspeakers do that. I agree though that if one is focussed on having a tube amplification then active speakers are not available ready made.

While many transistor advocates say their amps are neutral, I've yet to hear one that does not impart a coloration- that of brightness and hardness.

Ralph, I have owned three, the Class A Clayton M300 and M200 monoblocks and the Acoustic Imagery Atsah Ncore NC1200 monos. Maybe in comparison to certain tubed amplifiers there is a quality that some may call hardness but, in comparison to other SS amplifiers I have owned and heard, those amps mentioned would not be considered hard-sounding. IMO, none of the three would be considered "bright" sounding.

Unfortunately, I have yet to hear a perfect amplifier since all I have heard have sonic and operational trade-offs. I have owned some quite good SS Class AB amplifiers that have a hint of the brightness/hardness traits you mentioned but that were otherwise excellent. Since I notice this more after my last three amplifiers being Class A designs, and one Class D, I have wondered if maybe I am now more sensitive to crossover effects in class AB designs. In other words, could the "brightness/hardness" effect you point out be a byproduct of the Class AB design that some of the better designers are able to greatly reduce or even eliminate?

Al, combo filtering effect can not be ignored and I agree that a homogenous set of speakers would sounds best (on paper), but at least in my case the befits out weighted that particular set back.

Audiophiles bi-amplify. Do they build line array speakers with mismatching parts? For instance, a pair of subs, a pair of mids & a pair of tweets - all from different manufactures?

Is that audio heresy or can that be done the way wine and cheese are matched and paired with each other?

Can you achieve more audio performance by using a line array of speakers than you could with just one speaker?

I think the answer is YES because you can alway take the best and then add just a little bit more to make it better, regardless of what it says on paper.

Building a Line Array of Speakers might be too much to ask of most home users, but if a speaker builder went that route and allowed the home consumer to choose a line sub, a line mid and a line tweet - instead of putting it all in one box, it would provide for upgradeability in the future and unlimited configurations.

Other manufactures might also jump in and provide even more options.

BTW, doing 20hz is not always the most important criteria IMO, for that matter many loudspeakers do that.

Agreed, but as a manufacturer with a need for a reference, while that is not the most important criteria, its not acceptable if the bandwidth isn't there. Our amps go to 2Hz with full power and we want to know what's up when we play them. Plus the bass is really nice :)

In other words, could the "brightness/hardness" effect you point out be a byproduct of the Class AB design that some of the better designers are able to greatly reduce or even eliminate?

'Brightness and hardness' is a product of trace (0.005%) amounts of distortion, often containing the 7th harmonic. The ear is very sensitive to the 7th harmonic as it uses it (and others) as loudness cues to determine how loud a sound is. The ear/brain system converts all forms of distortion into tonality. That is why an amp can sound bright but measure flat on the bench.