Change to Horns or stay Dynamic

Pacific Island,

I have heard some excellent active systems. The main negative with them, is that the market is unresponsive to them. I think, audiophiles would rather be able to choose thier amps then have them dictated. Yet, I am in agreement that well executed active systems (I have only heard a few, not ATC or PMC yet) can easily outperform most passive systems in terms of dynamics. A speaker that truly surprised me was Backes & Muller that is fully active with what appears to be a digital crossover or something similar. But the price was close to 100K fully executured.

I dont feel active has any advantage in sound quality over well designed passive, you will get greater dynamics for you are running multiple amplifers with an active and a bit less insertion loss over passive but this is a nonissue if networks of proper design. A well designed 1st order will not limit dynamic range. I will say its easy to design a loudspeaker for active crossover much harder to design proper passive networks. For awhile I ran a 4 way horn system with active crossovers had 8 mono amplifiers what a pain to get it all right so many cables so much to go wrong. Still I use active for crossover designing. Gets me in the ball park so I have to exparament with values a bit less.

I dont feel active has any advantage in sound quality over well designed passive, you will get greater dynamics for you are running multiple amplifers with an active and a bit less insertion loss over passive but this is a nonissue if networks of proper design.

I agree that "well designed" is far and above more important than active or passive...good drivers and good drivers selection and implementation is fundamental starting point for a good speaker no matter how it is amplified...which is why I trust design to experts like yourself!

although....

How about eliminating IMD and higher order harmonic crossover distortion from an amplifier for a large bass woofer driving both a woofer and a tweeter?

Correcting for Phase?

How about using a Class AB for the woofer and pure class A for the tweeter?

Fundamentally there seems something at cross purposes in most passive designs where you hook up the same power source to something as delicate and sensitive as a tweeter (milli amps) AND to something as big and powerful and thunderous as a bass woofer (amps)...

Active Speaker Proponent

Pacific,

Your argument about home audio listening is valid if you listen at fairly low average spl levels of lets say, around 75db. Because for a good sense of dynamics a loudspeaker must be able to easily handle 20db peaks above the average level with no compression. Thats the minimum requirement and unfortunately the Scan favorites fall short of this target at anything above mid 90's db. So if you want to listen at realistic average levels of say 95 -100 db you will need the speaker to handle a not-so-unrealistic 120db peak levels and that's at the listening position no less.

For audiophile drivers core size and voice coil size are of secondary importance. Contrast this with the pro drivers' big voice coils and oversized and vented magnetic cores that can sustain prolonged periods of abusive power (read 400-600 watts) with just maybe 2db of thermal compression while playing at around 120db average level. There really is no comparison! Thermal compression is real and one of the most important as well as overlooked parameters in loudspeaker performance. It's perhaps not surprising that this is the case for the audiophile speakers as the driver core is the most expensive part of the assembly and the designers using the same logic consciously chose this set of compromises.

But make no mistake, as excessive as these db levels might seem at first, for the person that wants realistic reproduction at the home this is what will be required of the system.

Cheers,
George

Dgad: You bring up a common misunderstanding about active systems. Many do have built-in amps, but that's not necessarily a given. Some use external amps, e.g., Linkwitz Lab Orion, Gradient Revolution (I think), Morrison, Nomad Ronin, among others, including what I build.

Yes, the initial set-up is a little more involved, but once you've got it connected, you're done. The gains of active out weight the extra work. And if you want control, an external active x/o allows for far greater control than a fixed internal passive.

Here's another link that goes into the specific benefits of active: http://www.tnt-audio.com/casse/active_speakers_intro1_e.html