speaker excursion..."mo power"..and bass..Sean

I think the damping factor issue is directly related to the speaker in question, which may very likely have a very low moving mass and very high magnetic field and very short excursion length(such as my speakers), and thus have a very significant amount of its own internal damping ability.

In cases such as this, high numerical "damping factors" may actually inhibit transient response, and may not be an advantage at all.

As long as the relationship between the amp's output impedance and the speaker's relative impedance at any given frequency(damping factor) remains enough to control the speaker(>5), then it is sufficient in that circumstance. It is when the speakers have poor internal damping characteristics(ie high moving mass/low magnetic field strength/very long excursion length) where problems are more likely to be "fixed" by high electrical damping factor numbers.

Regarding high power being "better" than low power, we all know I'm in the "low power" camp. I think(and I'm pretty sure Sean agrees) that you are much better off to have higher efficiency speakers than to try to overcome low efficiency speakers with brute force, because of the exponential curve of power needed to add a few db to the output.

Also, it has been my experience that high power amps seem to be less "delicate" in nuances and details, due to the beefy construction needed to handle all that power. And in addition, to have power like that, you simply have to go out of Class A operation, which I don't like to do.

And, when you have low efficiency speakers, you have a higher "low-level detail threshold" because it simply takes more power to make the speaker move at all, so that some very low level stuff never even makes it out of the speakers, unless you have it turned up alot.

If the speakers are high efficiency, you can still get pretty loud SPL, with great low level detail, with very low power amps. I do realize that this normally sacrifices some of the very low bass. I think it is not a bad trade-off.

I do realize that this (very low power amps -high efficiency spkrs) normally sacrifices some of the very low bass

As you note, "normally". You can add active subwoofs for very little outlay and resolve the issue (if issue there is).

Whoa!

This thread had a great technical edge and now its tumbling out of control.

Passive crossovers are "voltage dividers", this is where the power goes, to ground especially in 2nd order and filters with notch filter etc. There are small losses in the components but the passive filter itself is a loss as it is addressing the fully amplified signal.

Drew/Bombay & Sean your original long posts were about 75% correct but this second group is getting into the land of speculation. Again good posts but now you guys are down to about 50% correct.

Sorry,I don't have time to correct the errors point for point.

Cinematic_systems...In a passive crossover, power does indeed "go to ground", but it goes through the drivers, which is the whole point of the thing. The power "wasted" by notch filters is minimal, unless the drivers are truly aweful.

The 10 AWG air coil inductors in my MG1.6 have about the same resistance as the original iron core inductors. This is why most speakers use iron core inductors.

When estimating the broadband signal equivalent to two bandlimited signals, the usual approach is to do an RSS. For example...

100^2 + 60^2 = SIGNAL^2

SIGNAL = 117

If the two band limited signals are equal, the equivalent broadband signal is maximized at 1.41 times the band limited signal.

However this assumes that the two bandlimited signals are uncorrelated, and this is not typical of music, where loud low notes are often simultaneous with high frequency harmonics, not to mention cymbal clashes.

As to tweeters burning out...I guess that some may be huskier than others, but I just took out two SEAS Excel T25CF-002 Millenium tweeters with about a three second burst of noise due to an interconnect problem. And these tweeters were not driven directly from the amp, but rather through a passive crossover. However, replacement voice coils are available, and Madisound even installs them for free. This suggests to me that blown out voice coils must be quite common.

Cinematic_systems...Whoops! You are right that in a second order or higher passive crossover some power is "dumped to ground". For example, for the woofer, after the inductor rolls off the highs, a capacitor to ground rolls them off further. However, I don't believe that the "dumped" power amounts to much, as the "dumping" starts near zero at the X/O frequency and increases at 6 dB/oct, but working with an input that is already rolling off at 6 dB/octive. Perhaps there is an EE out there who still remembers how to calculate the "dumped" power in a second or third order crossover. Fourth order would involve a second "dump".

If Sean is right, and we all got rid of passive crossovers, perhaps the global warming problem would be solved.