[William Sommerwerck]

"Trevor" wrote in message ...
"William Sommerwerck" wrote in message
...

There are such measurements, of course, but as far as I know,
no one knows what they are.

"As far as you know" is not saying much, then, is it?

Enlighten us, o audio sensei.

[Scott Dorsey]

William Sommerwerck wrote:
"Arny Krueger" wrote in message
"William Sommerwerck" wrote in message

If a product has "good" measurements (though no standard of goodness has
been established), it must sound good, and vice versa.

There was a time when the correlation between the then available audio
measurements and reliably perceived sound quality was tenuous, to say the
least.

Even though you obviously have not kept up technically William, those days
are gone.

So it is now possible to design an amplifier and know that it will "sound
good", simply on the basis of measurements? Point me to the documentation. (By
the way, there's a book making such a claim. It's from a British engineer
whose name I forget, and it's gone through several editions. It's worth
reading. I assume you have, Arny.)

For the most part, these days you can. We now have measurements that we know
match very well with audible effects for most conventional amplifier topologies.

That's not to say that things don't get overlooked sometimes, and that's not
to say that the next great new amplifier topology might have some artifact that
we don't know how to measure.

But for the most part, measurements have come a long way since the 1990s.

I can recommend Doug Self's book on power amplifier design.

While I don't agree with Arny that we have measurements that can detect all
possible audible effects (especially where transducers and rooms are concerned),
amplifiers are the one place where we have things sealed up pretty well.

The claim that Crown K1 or K2 amplifiers sound awful is belied by
numerous reports from owners to the contrary.

These reports were based on carefully performed ABX tests, I assume. Because
otherwise, they're not valid, and you shouldn't be citing them. It wouldn't be
"scientific", right?

I can attest that the K1 sounds terrible, and I am pretty sure I can make
reasonable measurements showing why. And, I agree that the null test is
the first place I'd begin.

The problem with the null test, though, is that it not only points out all
kinds of audible effects, but small amounts of group delay will cause a large
null signal to appear but without causing much audible degradation. So the
null test can indicate a lack of a problem but it cannot necessarily indicate
a problem.

BUT, reasoned and logical analysis of the residual signal can often help
determine the source.

My guess is that someone at Crown probably did do a null test on the K1 but
that they decided it sell it anyway.
--scott
--
"C'est un Nagra. C'est suisse, et tres, tres precis."

[William Sommerwerck]

"Scott Dorsey" wrote in message ...

I can recommend Doug Self's book on power amplifier design.

That was the book I was referring to. I read it earlier this year. I was
impressed by what he was trying to do (and a lot of what he said made sense),
but I was disappointed that he didn't seem to reach a point of "final
understanding". Perhaps I'm being unreasonable.


The claim that Crown K1 or K2 amplifiers sound awful is belied by
numerous reports from owners to the contrary.

These reports were based on carefully performed ABX tests, I assume.
Because otherwise, they're not valid, and you shouldn't be citing them.
It wouldn't be "scientific", right?

I can attest that the K1 sounds terrible, and I am pretty sure I can make
reasonable measurements showing why. And, I agree that the null test
is the first place I'd begin.

If you get around to testing it, I'd like to know what you find. The next time
I speak with Doctor Barclay, I'll ask him if he has access to the hardware, or
can suggest a computer-based equivalent.


The problem with the null test, though, is that it not only points out all
kinds of audible effects, but small amounts of group delay will cause a
large
null signal to appear but without causing much audible degradation. So the
null test can indicate a lack of a problem but it cannot necessarily
indicate
a problem.

This was known by QUAD. The "direct" signal had to be subjected to the same HF
rolloff produced by the amplifier, or you wouldn't get a good null.


BUT, reasoned and logical analysis of the residual signal can often help
determine the source.

One would hope so!

[MG[_4_]]

"Peter Larsen" wrote in message
...

Frank Stearns wrote:

(Scott Dorsey) writes:

snips

I have regularly had people in the music and non-audio engineering
worlds ask me about car stereos. I have to explain to them that I
have the original AM radio that came with the car.

They are usually shocked. But frankly, cars, even ones far more
modern than mine, are too loud. I wear earplugs while driving.

+1

I do exaclty the same.

Frank
Mobile Audio

Kind regards

Peter Larsen


Earplugs while driving would seem to be a dangerous thing.

[hank alrich]

MG wrote:

"Peter Larsen" wrote in message
...

Frank Stearns wrote:

(Scott Dorsey) writes:

snips

I have regularly had people in the music and non-audio engineering
worlds ask me about car stereos. I have to explain to them that I
have the original AM radio that came with the car.

They are usually shocked. But frankly, cars, even ones far more
modern than mine, are too loud. I wear earplugs while driving.

+1

I do exaclty the same.

Frank
Mobile Audio

Kind regards

Peter Larsen


Earplugs while driving would seem to be a dangerous thing.

Not at all. Earplugs reduce the level at the eardrum, but the ear's
sensitivity threshhold drops a lot in the relative quiet. You can still
hear well enough to drive safely, assuming one is capable of driving
safely.

--
shut up and play your guitar * http://hankalrich.com/
http://hankandshaidrimusic.com/
http://www.youtube.com/walkinaymusic

[geoff]

"hank alrich" wrote in message
...
MG wrote:


I have a small low-profile sub in my car. Means you don't have to have the
rest shreiking in order to hear any bass, which is a large part of most
peoples' problem, I think.

geoff