[William Sommerwerck]

"Les Cargill" wrote in message
...
William Sommerwerck wrote:

His essential point -- ultrasonics are a liability -- remains quite true.

That assumes amps and speakers suddenly misbehave badly above the upper
limits of human hearing. That's unlikely.


"Sampling does not affect frequency response."

Not quite true. The sampling function itself has an "amplitude envelope"
that varies as (sin x) / x. The wider the sampling function, the greater
the
ampliftude variation introduced.

Cite, please?

Any book with a thorough discussion of sampling.

Yeah, that's the sinc function/kernel but it does not mean that there's
any nonlinearity or response change over the published passband
of a properly ... sampled system.

There has to be some, because you can't have an infinitely narrow sampling
function. In practice, it's not of any major importance. But there /is/ an
effect on frequency response, however small.