"Bob-Stanton" wrote in message
om
"Arny Krueger" wrote in message

Many people claim (two channel) SACD and DVD-A sounds better than
the old 16-bit CD's. I'm looking to see if there is any reason why
this should be so.

You've got the cart way in front of the horse. First find out if
there's any facts to justify. That would be the scientific approach.


The facts are, as stated above: many claim that SACD and DVD-A sound
better than 16-bit CD's.

So what? People claim lots of crazy things. Flying saucers, anybody?

Guess what, there's plenty of evidence that higher sample rates and
longer data words offer no audible advantage over 16/44 as a
distribution format.

I'm looking for something more accurate than just listening tests.

When it comes to audibility questions, there is no known better way.

With listening tests, any imperfections in the signal source can mask
the difference between systems.

More significantly, the listener's ears mask the differences between
systems, big time.

For (an extreme) example, Suppose we recorded Thomas Edison's first
recording, "Mary had a little lamb...", on SACD, DVD-A, CD-16 bit, and
recorded it on an old 78 RPM wax record cutter. Listening tests would
show that the old wax record system sounds just the same as SACD.

Perhaps. OTOH there might be quite a bit of ultrasonic content to the
various spurious responses in that wax cutter.

Listening tests are not easly repeatable.

The seem to converge to consistent results pretty quickly.

Listening tests are not nearly as sensitive as test instruments.

Of course, but this was about audibility, not measureability, no?

I know that you believe there is no reason to know what the
distortion of a CD player or amplifier is, as long as it is "below
audibility".

Again, what is the problem with this?

Nothing, as long as you don't care to know very much.

What else is there that is relevant to know?

I prefer to know what the level of distortion is, and make my own
judgment as to audibility.

False causality. I'm not against knowing what the level of
distortion is for other reasons, but judgments about audibility
should be based on actual listening tests.

If listening tests are not correlated to measured performance, what do
they tell you?

They tell me something we both seem to agree about. Listening tests are not
nearly as sensitive as test instruments.

Virtually nothing. Only that two things sound the "same".

Which suggests an important truth - the problems with sound recording and
playback are elsewhere.

Suppose I wanted to know if the temperature in my living room was the
same as the temperature in my dining room. I could take ten people,
blind fold them and have them stand in my living room, move them back
and forth randomly between the two rooms, and see if they could tell a
difference. After a while I could make a determination that the
difference in temperature is or is not, subjectively detectable.

OK.

Yes, the double blind test method "works" and is scientific. But,
wouldn't it be a lot easier (and more accurate), to just put a
thermometer in each room?

That's part of the charm of measurements. They are easy, but their relevance
to human perception is not always a given.

First comes the measurement, then comes the subjective evaluation. All
you want to do is a subjective evaluation. You didn't put the cart in
front the horse. You have a cart *without a horse*.

Depends how you define the goal of audio reproduction. Most would define it
as being the perception of a life-like if not live performance.

There's that nasty "perception" word again.