Damping factor or watts?

DF will not control the driver excursion. The driver will move somewhat with inertia when the signal stops regardless of DF. What happens is that the moving driver acts like a microphone as the cone moves in the voice coil creating an emf. If the amplifier DF is very high, it's low output impedance presents a short to the speaker. This prevents a back emf to the speaker which could cause the driver to oscillate as it repeats the process.

What stops the cone (or controls it) is the air mass loading on the driver from the speaker enclosure (Q). Also, the crossover and the voice coil add to the overall DF in addition to the speaker cables so the amplifier DF will change once hooked up to a speaker. And with a planar speaker, the air loading is quite high which helps things out with low DF amps.

Then there are the unavoidable compromises in amplifier design: for an amplifer to have a high DF it has to have a very low output impedance which then will require more global negative feedback. This creates another problem to deal with in terms of distortion. Bottom line is that numbers don't tell you much.

There are reasons (immaterial here) why some ribbon devices may sound slightly better with a medium DF than an extremely high one -- hence the use by some of tube amps.

Otherwise, your system looks fine on screen -- so the problem must be in the listening! What's bugging you?

While Back EMF is not completely irrelevant in this discussion, I didn't feel it warranted inclusion in the definition. For a better understanding of "damping factor", see these: (http://en.wikipedia.org/wiki/Damping_factor) Particularly pg 1, para 2,3 / pg 4, para 1 (http://www.classic-audio.com/marantz/mdampingfactor.html) Notice how often the word, "control" is used. Tube amps almost invariably have low damping factors. To say that Maggies need a high one, but that they sound best with tube amps is contradictory. Here's an interesting little article on the MMg's you may enjoy Hlgoh: (http://www.enjoythemusic.com/magazine/viewpoint/1199/donibbles.htm)

It's interesting how those three different URLs came out with the same "wikipedia" addy in the post! Hlgoh- The main point is: Don't be confused by peoples' opinions. Most only have those and not much in the way of truth. Do the research, and make decisions based on facts. If you want truth in your music reproduction: Listen to/get familiar with a lot of live music(amplified AND acoustic), and base the judgement of your system's reproduction on that. Enjoy your listening!!!

The idea of damping factor having an effect on the sound of a speaker is mostly myth. However, it is a bit tricky seperating myth from reality. Here's what is really going on:

Almost any amplifier driving a speaker will have an output impedance that is lower than the speaker, but the important thing to understand is that the speaker is reproducing signals from the amp. As the output impedance of the amplifier approaches the impedance of the speaker, the distortion of the amplifier rises. It is this increase in distortion that accounts for the muddy sound that results- the so-called 'loss of control'. IOW the amplifier does not 'loose control', it simply distorts more.

To really understand why this is so, you have to understand the fundamental operating principle of the speaker itself. When the amplifier puts power through the voice coil, the result is that the diaphragm is deflected. The deflection is related to the power that the amplifier is making at that instant. As the amplifier makes more and less power, both positive and negative, the speaker diaphragm follows the waveform of power presented to its voice coil.

IOW the diaphragm is powered **all the way** through the amplified waveform. There is no place at all where the amplifier 'lets go' of the speaker. In understanding of this fact is also the understanding of why 'damping factor' is one of the more misunderstood myths of audio.