PenguiN wrote:

Nothing stupid about it. If both systems are linear then they will work
in an identical manner.


The system by which a single ideal speaker surface transduces an
electrical waveform my moving and producing a series of travelling
pressure changes in the air is *not* a linear system.

Please prove that. It has yet to be done.


Bob
--

"Things should be described as simply as possible, but no
simpler."

A. Einstein

Bob Cain wrote:
PenguiN wrote:

Nothing stupid about it. If both systems are linear then they will work
in an identical manner.


The system by which a single ideal speaker surface transduces an
electrical waveform my moving and producing a series of travelling
pressure changes in the air is *not* a linear system.

Please prove that. It has yet to be done.

I can prove that easily, but not in any way that has anything to do with
doppler effect. There are plenty of amplitude nonlinearities, from a
dead band due to spider friction, to break-up modes at high levels. But
none of them have anything to do with the doppler issues.

The doppler issues, though, don't have anything to do with amplitude
nonlinearities. The earlier reference made to Terman is a good one.
--scott
--
"C'est un Nagra. C'est suisse, et tres, tres precis."

Scott Dorsey wrote:

Bob Cain wrote:

The system by which a single ideal speaker surface transduces an
electrical waveform my moving and producing a series of travelling
pressure changes in the air is *not* a linear system.

Please prove that. It has yet to be done.


I can prove that easily, but not in any way that has anything to do with
doppler effect. There are plenty of amplitude nonlinearities, from a
dead band due to spider friction, to break-up modes at high levels. But
none of them have anything to do with the doppler issues.

Right.


The doppler issues, though, don't have anything to do with amplitude
nonlinearities. The earlier reference made to Terman is a good one.

I'm still hoping someone with access to a source containing
the expression describing pressure/velocity in the wave as a
function of the velocity of the piston will transcribe it to
one of these threads. If it exists, it's just an equation.

If it doesn't, we simply _must_ consider why that is.


Bob
--

"Things should be described as simply as possible, but no
simpler."

A. Einstein