Re: ALSA sound recording frustration

[Napoleon <rri0187@attglobal.net>]

John Hasler wrote:
> Napoleon writes:
> > Without getting into the more technical stuff, for correct operation
> > impedances need to match.  Any mismatch lower performance.  A small
> > mismatch probably won't be noticed but a larger one will.
>
> You need an impedance match for maximum power transfer but that is rarely
> what is wanted (it means equal power dissipation in source and load).  You
> also need to terminate transmission lines at one end or the other in the
> line's characteristic impedence but unless your audio cables are miles long
> that doesn't matter either.

Sorry - meant this to go to the list.

It's not just maximum power transfer.  An impedance mismatch also
affects frequency response; the greater the mismatch, the greater the
high frequency rolloff.  A great enough mismatch and it is quite
noticeable, even at audio frequencies.

And transmission lines need to be terminated at BOTH ends in the line's
characteristic impedance.

Maybe it doesn't matter to you - but it does to most audiophiles.  They
can hear the difference.