horn-loading: 100% efficiency ?!

[calvert73]

No system be it mechanical or electro mechanical can be 100% efficient, its like a perpetual motion machine, it just cannot exist, at least not in this Universe.

RC

[Rocky]

Originally posted by calvert73
No system be it mechanical or electro mechanical can be 100% efficient, its like a perpetual motion machine, it just cannot exist, at least not in this Universe.

RC

I think we all can agree to that, and that applies to efficiency. But sensitivity at some point in space on the other hand, can surpass the share sound pressure of what an ideal 100% efficient unidirectional loudspeaker could produce (total input power minus losses radiated into freespace), if the acoustic energy produced, how unefficient it may be, is directed to a very limited area.. Sensitivity and horns becomes a matter of directing all the acoustic energy to the area where the listeners ears is likely to be found. Because of this, a horn can reach very high sensitivity on axis (or within a limited area), without breaking any physical laws of efficiency.

[noah katz]

Hi Tom,

Thanks for the explanation.

Still, I'm not clear on if what I said about Rdc is correct. Any reason a superconducting VC wouldn't be a good thing?

I'm a computer klutz, but I will find a friend to make a copy of your fireworks recording.

Thanks

[Pano]

Hi Tom,
Thanks for the great fireworks track. Always good for testing woofers.

There is a discussion of the track HERE.

Maybe you can answer a few questions about the recording?

[e-side]

Originally posted by Tom Danley

The idea with a horn is you place an acoustic load on the moving system such that the impedance peak is dropped to about Rdc X2 (for a 50% efficient speaker).

(...)

One can have a horn that is over 50% by having the resistive impedance rise to greater than 2X Rdc but normally this is not done as it leaves a narrow efficient bandwidth.

I did some simulations in hornresp but the impedance peak never came close to 2*Re for a calculated 50% efficiency design with proper mouth size. For every angle the peak was far above 2*Re...