Damping factor or watts?

Rodman99999, in the thread wherein I mentioned speaker cable length, I also mentioned 'characteristic impedance'.

As to your earlier question, the answer is 'yes'. I can point to a number of other examples wherein we find that a mythology has been created- where a mistake was made, something was considered negligible that later turned out not to be, or where something was said because a lot of money was involved.

Reread may statements about how the speaker works. Anytime a speaker is reproducing a signal, there is a cone position that corresponds to the amount of power in the voice coil. There are no musical signals that require full excursion and then have the amplifier 'let go' of the speaker. At any time when a speaker is making sound, the amplifier is **powering** the speaker to do that, whether it is full excursion or very nearly rest.

There is a story about the Emperor's new clothes. It is there to allow you to understand when something is being made up, and to see through it, even when the entirety of the culture is saying that the made up thing is real. Yet, the fact that an amplifier puts power through a speaker cannot be denied. So- you can go ahead believing the 'damping factor' story and that will not hurt you, but OTOH if you tend to look at these things closely, you will see after a while that that story can generate more questions than answers.

Atmasphere- I've based my belief in my understanding of electro-magnetic fuction and Newtonian physics. Inertia= When a body is in motion, it tends to stay in motion unless acted upon by an outside force. Yes- the music signal from the amp is driving the speaker(electro-magnetically). While this speaker is going through the motions of reproducing sound, it's mass is also trying to continue to move in the last direction(large transient) it was told to go by the amp(inertia). Of course- the higher the mass, the greater the inertia. The amp's ability to counteract this tendancy determines how faithfully the signal is reproduced. The effects of back EMF(and, perhaps, quantum physics) not withstanding- Is there something flawed, or mythological to this? If I am wrong(unlike some), I like to be corrected. Truth is more important to me than holding stubbornly on to a misconception. Please- enlighten me.

Rodman99999, I'll take you up on your bet. My house up against your farm. Here goes:

The speakers used were 92 dB efficient two-ways.

The woofer in the RMAF '06 room had a moving mass of 79 grams; Fs = 40 Hz; Qes = .35; Qms = 11.69, and Vas = 77 liters.

The speaker in the RMAF '07 room had two woofers, each with a moving mass of 41 grams [combined moving mass of 82 grams]; Fs = 31 Hz; Qes = .32; Qms = 4.35; and Vas = 121 liters [combined Vas of 242 liters]. This speaker is a bipolar, so the efficiency is 3 dB lower than the combined T/S parameters would indicate.

I am the speaker designer (thanks for asking!). The amplifier was an Atma-Sphere S-30.

So tell me.... just where is my new farm located??

;o)

Duke

Not exactly INefficient though, are they? So tell me: Were you, by any chance, using any kind of auto-xformer between the OTLs and your speakers? Gotta keep digging for factors here before I give up any ground!

Rodman99999, on just about every speaker that I can think of, the suspension gets stretched as the speaker diaphragm moves away from the resting point. Furthermore, the speakers that have the most back EMF, i.e. the ones that are the most reactive, tend to be high efficiency designs, not low efficiency. In most high efficiency designs, the speaker is usually moving less, not more, due to the nature of the design.

The back EMF of such speakers is often the reason that amplifiers with large amounts of feedback (and often higher 'damping factors') usually sound more shrill on these speakers, as the back EMF becomes an unintended part of the feedback signal.

This is probably not what you would have initially thought. I know it was not for me! It turns out to get highly reactive speakers to calm down, you need an amp without feedback, i.e. low damping factor. In fact what you start to get about this is that the damping factor is for the most part irrelevant, whereas the amount of loop feedback is (the less the better).

So anyway, the issue of stopping the mass of the speaker is almost non-existant, unless you intend to amplify non-linear /non-musical signals. An example of that might be a linear motor in a disk drive. Damping in a situation like that would be quite important as the driving signal is not a function. But for audio, the amplifier is always sending the speaker a signal (power), and this power is always moving the cone incrementally in a new place.

To be otherwise suggests that the signal is not a function (which it has to be by definition). Like I mentioned before, the amp does not push the speaker to full excursion and then 'let go'. Since the signal is a function the cone is literally under power all the way back to zero and then beyond.

When I started this business I believed in damping and a lot of other things that I later found to be made up. I was fortunate though that I had enough exposure to the right classes in college and had read enough texts from the 'old days' that I was encouraged to look past the 'company line' to see what was really up. Turns out there have been two design paradigms in conflict in audio for a long time:

http://www.atma-sphere.com/papers/paradigm_paper2.html

And I definitely subscribe to one and not the other, just like everyone else in audio :)