ATC active vs. passive

Brad gave a great description of the ATC 50. I'll add a big reason why active is better. Amplifier tests are done with resistors of a given value. Real speakers are not resistors to the amp, the are also capacitors and inductors and their affects vary with frequency. Amps like resistors, not capacitors and inductors. That's why great amps spec often like ordinary amps but sound better. They are built(big part is the power supply which is costly) to handle capacitive and inductive loads. Active speakers are much less reactive. The crossover comes before the amps. And that is a big deal.

I'll ad one historical note. My friend, Gordon Holt, the founder of Stereophile purchased a set of active ATC 50 speakers. Gordon had a great ear. And he did a lot of live recordings. He told me the ATC 50 active speaker was one of a very few speakers that made his recordings sound real like they sounded when he was recording.

@arion wrote:

... my experiences strongly suggest that active systems usually perform better if properly designed.

+1

Our active speaker systems are different than the ATC active systems in that you can use any amplification you choose ...

Which simply implies that your speaker systems are outboard actively configured, whereas the ATC’s are bundled active speakers (with the exception of the SCM300’s). I find it’s commendable that you’re working from an outboard active platform (like I do myself, and which any DIY’er/audio entrepreneur can pursue) that grants the user the freedom of choice with regard to amplification, and essentially any other aspect (and I’m aware much more than outboard active config. alone is part of your product concept).

Moreover: this way the dichotomy between active and passively configured speakers systems can be diminished, as most see it as - in effect - a bundled vs. separate component distinction and solution, and not as something that per definition comes down to where and how the crossover function is applied, and that both of these approaches can be attempted as separate component solutions.

Active vs passive-- keep in mind that the amp inside the speaker will probably not last that long.  If you want to potentially keep your speakers for decades, then I would go with passive.  I'm not saying that the internal amp will die in a decade, but why take the chance?  How long is the warranty on the ATC actives?  This is not a comment on the sound of the ATC's.  This is just a comment from someone who owned a sub-- a $2,500 sub-- that died after a decade due to the internal amp dying.  Class D amps are notoriously difficult to repair.  I'm guessing that most active speakers have Class D amps inside them.  Anyway, just my 2 cents.  If anyone can counter what I'm saying here, I'm all ears.   BTW the manufacturer quoted me a price to fix the sub that was about 75% of what I paid for it.  So I passed on that.

I don’t want to derail this conversation, but the whole solution really matters. I have not heard ATC’s nor am I privy to their internals. The correct approach, IMHO is to listen and judge for yourself.

Having said that, I want to point out that just because ATC makes 2 versions of the same speaker box with the same drivers doesn’t mean the choices in the crossover are the same, so a lot of these points about one or the other version being naturally superior are hard to prove. For myself, I would find it nearly impossible to make the same passive and active speaker. The biggest difference between active and passive is that I have to make fewer design compromises in an active speaker.

For instance, I just made an active 3-way center channel with 4th order LR filters between every driver, all drivers in positive polarity. I’d never attempt this as a passive, and would be relegated to 2nd and 3rd order filters and highly unlikely they’d maintain the same polarity. Active, especially with DSP, just makes everything so easy. If I were at ATC, and they asked me to "activate" an existing passive speaker it would be just incredibly tempting to enhance it’s performance when transitioning.

So, point is, no idea of the ATC speakers attempt the same driver crossovers, polarity, etc. so hard to use them as a judge. In fact, it’s just super hard to do a real apples to apples comparison of any active vs. passive speaker. Judge the whole package and do so on a case by case basis.

My tube amp is Auris fortissimo, 100W Push pull. 
I’m concerned it wouldn’t be enough to power SCM150 that I’m considering. 
I have a big room, I like to listen at high volume. I am in the position to buy anything ranging from 50 to 150 both passive and active. I’m trying to make the right decision