In article qPh2f.3087$jw6.857@lakeread02,
"ScottW" wrote:

"MINe 109" wrote in message
...

Thanks. When that center channel happens, I'll check out the Delos test
disc.

Isn't the levels signal out of most receivers pink noise?
Both my receiver and DVD player (as it has builtin decoders) has level test
signals that sounds like pink noise to me.

I don't have a receiver yet. I think my dvd player mmight have some kind
of test tone.

Stephen

"MINe 109" wrote in message
...
In article qPh2f.3087$jw6.857@lakeread02,
"ScottW" wrote:

"MINe 109" wrote in message
...

Thanks. When that center channel happens, I'll check out the Delos test
disc.

Isn't the levels signal out of most receivers pink noise?
Both my receiver and DVD player (as it has builtin decoders) has level
test
signals that sounds like pink noise to me.

I don't have a receiver yet. I think my dvd player mmight have some kind
of test tone.

Pink noise sounds like a radio not tuned to a station with the muting off.
No tone quality to it.

ScottW

In article m%m2f.3105$jw6.768@lakeread02,
"ScottW" wrote:

"MINe 109" wrote in message
...
In article qPh2f.3087$jw6.857@lakeread02,
"ScottW" wrote:

"MINe 109" wrote in message
...

Thanks. When that center channel happens, I'll check out the Delos test
disc.

Isn't the levels signal out of most receivers pink noise?
Both my receiver and DVD player (as it has builtin decoders) has level
test
signals that sounds like pink noise to me.

I don't have a receiver yet. I think my dvd player mmight have some kind
of test tone.

Pink noise sounds like a radio not tuned to a station with the muting off.
No tone quality to it.

Yes, like on my Stereophile test cd.

Stephen

ScottW wrote:

"MINe 109" wrote in message
...
In article ,
Howard Ferstler wrote:

Me:
My next thought involves an already inexpensive Polk center available
even cheaper at Fry's. I think I have a pink noise source on a
Stereophile test cd.

The Delos "Surround Spectacular" test disc (I believe it is
still available from the Delos Records web site) has Dolby
Surround (matrixed) encoded pink-noise test signals that
include left, center (left plus right), right, and surround
(left minus right) signals that make it pretty easy to
compare spectral balance in all four Dolby Surround
channels. The Ovation Software "Avia" test DVD has similar
signals in Dolby Digital form for the standard five
channels. (They also have a web site that takes orders.) The
version put together for Sound & Vision magazine even has an
additional test signal for the center-back channel in 6.1
systems.

All three also have test signals to help set up subwoofer
levels and crossover phase dovetails. The Delos disc even
has signals to check out the ability of a Dolby Surround
(matrix) decoder and three speakers up front to deliver
half-left and half-right imaging with three front channels
and a derived (left plus right) center feed.

Thanks. When that center channel happens, I'll check out the Delos test
disc.

Isn't the levels signal out of most receivers pink noise?
Both my receiver and DVD player (as it has builtin decoders) has level test
signals that sounds like pink noise to me.

ScottW

Sometimes pink, but also sometimes what appears to be simple
white noise or narrow-bandwidth random noise. Any of it
should work OK, but regular pink noise, since it includes a
balanced amount of bass and treble (equal energy per
octave), works better at checking both level matching and
spectral balance, especially the latter.

Howard Ferstler

ScottW wrote:

"MINe 109" wrote in message
...
In article qPh2f.3087$jw6.857@lakeread02,
"ScottW" wrote:

"MINe 109" wrote in message
...

Thanks. When that center channel happens, I'll check out the Delos test
disc.

Isn't the levels signal out of most receivers pink noise?
Both my receiver and DVD player (as it has builtin decoders) has level
test
signals that sounds like pink noise to me.

I don't have a receiver yet. I think my dvd player mmight have some kind
of test tone.

Pink noise sounds like a radio not tuned to a station with the muting off.
No tone quality to it.

ScottW

Because pink noise generates an energy content that is
inversely proportional to frequency, the rate of change as
the frequency climbs is minus 3 dB per octave - resulting in
equal energy per octave. White noise (what you may hear
between stations or with some built in receiver signal
generators) is constant energy per unit of frequency, which
has constant energy per octave. As a result, white noise
seems much more treble heavy than pink noise.
Either can be used, by ear or meter, to set up balances
between speakers in a surround-sound rig, but the advantage
of pink noise is that it also allows one to check for
spectral balance similarities - by ear.

The reason white noise is favored by manufacturers who use
it with their receivers is that speakers that are different
in terms of their spectral balance abilities (typical when
using center speakers that are significantly at variance
from the left and right main speakers) will be easier to
match by ear. Mismatched speakers can at least be properly
level matched. The advantage of pink noise is that it allows
the user to see just how much alike his speakers sound in
terms of their frequency response smoothness and bass, mid,
and treble balance.

Howard Ferstler

"MINe 109" wrote in message


I don't have a receiver yet. I think my dvd player mmight
have some kind of test tone.

Stephen, you're so obviously not a mainstream kind of guy!

"ScottW" wrote in message
news:m%m2f.3105$jw6.768@lakeread02
"MINe 109" wrote in message
...
In article qPh2f.3087$jw6.857@lakeread02,
"ScottW" wrote:

"MINe 109" wrote in message
...

Thanks. When that center channel happens, I'll check
out the Delos test disc.

Isn't the levels signal out of most receivers pink
noise?

Yes.

Both my receiver and DVD player (as it has builtin
decoders) has level test
signals that sounds like pink noise to me.

Very likely.

Pink noise sounds like a radio not tuned to a station
with the muting off.

Close. The basic process that creates FM interstation noise
probably generates pink noise, but FM recievers have
demphasis circuits that roll response off based on 50 uSec
(Europe) or 75 uSec (US). IOW, above about 2 KHz FM
interstation noise gets softer-sounding.

No tone quality to it.

Well random noise has either no tones or every tone,
depending on how you look at it. Scientifically, every tone
would be closer to the truth.

If you narrow-band filter noise at any frequency in its
range, you will recover a tone that was a true and genuine
part of the noise signal. So, its more correct to say that a
noise signal contains every tone in its range.

White noise sounds something like high pressure air escaping
from a nozzle, and is pretty nasty to listen to.

Pink noise sounds less grevious, but is IME hardly fun to
listen to. Its more like the sound that waves make when they
crash on the shore. BTW I just spent a week hiking the south
shore of Lake Superior, so I heard this sound up front and
personal day and night for a week. There was a gale-force
storm one night, and that was pretty wild.

Interestingly enough, in the past 20 years equipment testing
has moved away from the use of noise as an audio test
signal. Not to say that people don't still use it, or that
using it is invalid. Noise is cheap and easy to make and it
can be helpful because of its lack of character.

If you play noise though an audio system and hear a distinct
character, then that character is probably due to a false
coloration of the system.

If the audio system is a guitar amp, then character and
coloration can be a good thing.

If the audio system is a home stereo system, then a false
sonic character can become a veil that stands between the
listener and the fine tonality of the music.

Anybody who tests equipment with a true random noise signal
is sort of condemning themselves to an old-fashioned,
out-dated kind of test. But it can be better than nothing,
by far.

"Arny Krueger" wrote in message
...
"MINe 109" wrote in message


I don't have a receiver yet. I think my dvd player mmight
have some kind of test tone.

Stephen, you're so obviously not a mainstream kind of guy!


We mainstream guys listen to test tones all the time.

In article ,
"Arny Krueger" wrote:

"MINe 109" wrote in message


I don't have a receiver yet. I think my dvd player mmight
have some kind of test tone.

Stephen, you're so obviously not a mainstream kind of guy!

Nope. I'm just curious about what's on the surround channels of my music
dvds and hybrid sacds.

Does anyone have opinions about the Polk R30 and center channel
currently very cheap at Fry's?

Stephen

Arny Krueger wrote:

Anybody who tests equipment with a true random noise signal
is sort of condemning themselves to an old-fashioned,
out-dated kind of test. But it can be better than nothing,
by far.

It has its uses, and is but one of several tests that can be
used to evaluate gear, particularly speakers. (It also comes
in handy when evaluating surround processors, needless to
say.)

One thing it can do is allow for comparison testing by ear,
again with speakers. That is, one can set up a pair of
speakers close together, feed them mono pink noise, and then
use the balance control to AB them. Doing this by ear will
quickly do three things:

1. It will show that even very good speakers, displaced
slightly in space, will have spectral balance differences at
the listening position that may be surprising. Indeed, even
the most subtle differences between speaker performance
(between supposedly identical speakers) will be easily
audible with a pink noise test signal. Switch to musical
source material and they may sound identical, but pink noise
will highlight those subtle differences emphatically. Hence,
pink noise is the equivalent of a good test pattern with
video.

2. If one of two speakers is defective (problematic or
inoperable driver) doing a pink-noise AB comparison will
highlight the problem immediately. It is a good test tool
for someone who does not have test gear and who wants to
know quickly if one of their speakers has a problem.

3. If power response is what matters most to an individual a
pink noise source, along with a good RTA, will do a fine job
of evaluating that aspect of speaker performance, at least
if the testing/listening room is decent and one has an RTA
with a continuous averaging feature. That allows one to move
the microphone slowly to get an average over a given amount
of space.

Yes, I know these days the emphasis (even with supposedly
knowledgeable enthusiasts and reviewers) is on the
direct-field, first-arrival signal getting to the listener.
(Thereby locking them into a sweet-spot listening position
for satisfactory performance.) There is a certain irony
here, because decades ago reviewers already felt this way,
and then along came guys like Villchur and Allison, and a
few others, and the concept of power response gained a lot
of support. This is perhaps why the old Acoustic Research
outfit managed to do so well for over a decade.

Unfortunately, most systems have problems delivering the
power-response goods, so many manufacturers went back to the
direct-field philosophy in order to rationalize the
limitations of their speakers. Today, many reviewers have
embraced the old view of the importance of the
first-arrival, direct-field signal, even though one does not
need to think much about it to realize that power response
eclipses the impact of the direct field in normal rooms even
with fairly conventional speakers.

I continue to believe that it is the total power response
that will matter most when it comes to the ability of a
speaker to simulate live music with good, "purist"
recordings. To get really good power response and spectral
balance at the listening position in most home-listening
rooms one needs a speaker with the widest broadband
radiation pattern possible.

Actually, my last sentence introduces us to another very
important aspect of loudspeaker performance. Mark Davis
showed a couple of decades back that the wide-angle,
full-bandwidth radiation pattern of a system is also
critical, and together those two (radiation pattern and
power response) are way, way, way more important than the
first-arrival, direct-field signal dealt with by various
gating measuring devices.

And pink noise, working with a good RTA, is a good way to
evaluate the power response. And one can also do a good job
of measuring the radiation pattern with an RTA and pink
noise, provided the job is done anechoically. Outdoors does
just fine.

So pink noise has its uses, and those uses are important.

Howard Ferstler

MINe 109 wrote:

In article ,
"Arny Krueger" wrote:

"MINe 109" wrote in message


I don't have a receiver yet. I think my dvd player mmight
have some kind of test tone.

Stephen, you're so obviously not a mainstream kind of guy!

Nope. I'm just curious about what's on the surround channels of my music
dvds and hybrid sacds.

It varies. Some will have not much more than large-space
hall ambiance, and those are usually classical releases.
This ambiance can have been specifically recorded, or the
engineer may have used a synthesizing device with more
conventional, two-channel master tapes to fabricate surround
ambiance for the surround channels. This is common with
reissues of older recordings. Interestingly, with a good
home-based DSP receiver an individual may be able to do
nearly as good a job with those older two-channel recordings
as the engineer does when pulling 5.1 sound out of
two-channels and making an SACD or DVD-A release.

Other recordings (these are usually pop items) may put both
ambiance and individual instruments into the surround
channels. I have heard some that even had a piano and/or
drum set in the surround channels. Vocalists, too. Some will
even create a "phantom" back-center channel and if one has a
6.1 processor it may be possible to switch on the
center-back speakers and get a more discrete center-back
effect. However, normally this can only be done with the
Dolby Digital or DTS alternate tracks on DVD-A releases,
because the receiver simply will not offer a center-back
playback option with 5.1 SACD or DVD-A.

Interestingly, many of those pop (and classical) releases
make little use of the center channel. Some ignore it
completely. There are probably three reasons for this:

1. The engineer simply does not like the tight focus of a
discrete center feed and prefers the more spacious and phasy
effect delivered by a phantom center.

2. The engineer may simply not know how to properly record a
center image for playback on a discrete center channel. It
can be tricky to get the center to have the proper hall
ambiance compared to the left and right channels. The
soloist may sound like they were recorded in a different
space from the ensemble. Done right, however, and a discrete
center soloist can improve soundstaging over a wider
listening area than what we get with a phantom effect.

3. Some knowledgeable engineers realize that the typical
center-channel speaker is horizontally mounted, high up on
top of a TV set and is not all that good to begin with.
Placement and quality problems will make the center feed
sound not all that good, so the engineer simply leaves out a
discrete center feed and goes with the phantom image.

Howard Ferstler

"Arny Krueger" wrote in message
...
"ScottW" wrote in message
news:m%m2f.3105$jw6.768@lakeread02
"MINe 109" wrote in message
...
In article qPh2f.3087$jw6.857@lakeread02,
"ScottW" wrote:

"MINe 109" wrote in message
...



Anybody who tests equipment with a true random noise signal is sort of
condemning themselves to an old-fashioned, out-dated kind of test. But it
can be better than nothing, by far.


What works better?