Some components are said to be phase correct while others invert phase.
Instructions for the latter typically include instructions to reverse the
speaker leads, ie, red the black, black to red, to restore proper phase. As
it's that easy to do, why don't manufacturers of equipment that invert phase
simply wire the outputs of their products 'backwards' (ie, "+" to "-" and "-"
to "+" at the RCA outputs) to restore phase within the product itself?

On 27 Oct 2004 00:03:40 GMT, (CCSman) wrote:

Some components are said to be phase correct while others invert phase.
Instructions for the latter typically include instructions to reverse the
speaker leads, ie, red the black, black to red, to restore proper phase. As
it's that easy to do, why don't manufacturers of equipment that invert phase
simply wire the outputs of their products 'backwards' (ie, "+" to "-" and "-"
to "+" at the RCA outputs) to restore phase within the product itself?

Because, at RCA outputs, the signal is single-ended, not balanced.
Connecting + to ground leads to no output. What you suggest would
work with balanced outputs.

Kal

"CCSman" wrote in message
...
Some components are said to be phase correct while others invert phase.
Instructions for the latter typically include instructions to reverse the
speaker leads, ie, red the black, black to red, to restore proper phase.
As
it's that easy to do, why don't manufacturers of equipment that invert
phase
simply wire the outputs of their products 'backwards' (ie, "+" to "-" and
"-"
to "+" at the RCA outputs) to restore phase within the product itself?

That will work for power amps. It won't work for preamps...and in some
cases, the phase inversion is only for certain sections of the preamp...e.g.
the phono inverts, the high level inputs do not, or vice versa.

CCSman wrote:
Some components are said to be phase correct while others invert phase.
Instructions for the latter typically include instructions to reverse the
speaker leads, ie, red the black, black to red, to restore proper phase. As
it's that easy to do, why don't manufacturers of equipment that invert phase
simply wire the outputs of their products 'backwards' (ie, "+" to "-" and "-"
to "+" at the RCA outputs) to restore phase within the product itself?

RCA jacks are not balanced connectors. There is no + and - on RCA jacks.
One side is always at ground.

Thanks for the responses- it did seem too easy

Harry Lavo wrote:
"CCSman" wrote in message
...

Some components are said to be phase correct while others invert phase.
Instructions for the latter typically include instructions to reverse the
speaker leads, ie, red the black, black to red, to restore proper phase.

As
it's that easy to do, why don't manufacturers of equipment that invert phase
simply wire the outputs of their products 'backwards' (ie, "+" to "-" and "-"
to "+" at the RCA outputs) to restore phase within the product itself?

That will work for power amps. It won't work for preamps...and in some
cases, the phase inversion is only for certain sections of the preamp...e.g.
the phono inverts, the high level inputs do not, or vice versa.

That begs the question... is all music recorded "in phase"?

Chung wrote in message ...
CCSman wrote:
Some components are said to be phase correct while others invert phase.
Instructions for the latter typically include instructions to reverse the
speaker leads, ie, red the black, black to red, to restore proper phase. As
it's that easy to do, why don't manufacturers of equipment that invert phase
simply wire the outputs of their products 'backwards' (ie, "+" to "-" and "-"
to "+" at the RCA outputs) to restore phase within the product itself?

RCA jacks are not balanced connectors. There is no + and - on RCA jacks.
One side is always at ground.
And not to get off this particular vein - - but what is the real
significance (or true effect) of components (ie-digital
processors/preamps/etc) featuring a "phase-invert" switch which, when
employed, does seem to make some sort of audible improvement (even
from song-to-song within a particular CD)? Is it a relaxation of "ear
fatigue" (although I'm using better than average components), or all
in my (and my wife's) head(s)? (Lucky me-I've got a wife who enjoys
my hobby with me!).

"MRJohnson" wrote in message
...
Chung wrote in message
...
CCSman wrote:
Some components are said to be phase correct while others invert
phase.
Instructions for the latter typically include instructions to reverse
the
speaker leads, ie, red the black, black to red, to restore proper
phase. As
it's that easy to do, why don't manufacturers of equipment that invert
phase
simply wire the outputs of their products 'backwards' (ie, "+" to "-"
and "-"
to "+" at the RCA outputs) to restore phase within the product itself?

RCA jacks are not balanced connectors. There is no + and - on RCA jacks.
One side is always at ground.
And not to get off this particular vein - - but what is the real
significance (or true effect) of components (ie-digital
processors/preamps/etc) featuring a "phase-invert" switch which, when
employed, does seem to make some sort of audible improvement (even
from song-to-song within a particular CD)? Is it a relaxation of "ear
fatigue" (although I'm using better than average components), or all
in my (and my wife's) head(s)? (Lucky me-I've got a wife who enjoys
my hobby with me!).

I expect to get thoroughly trashed here since this is not based on blind a-b
testing, but twice in my life I have actually determined that my stereo
speakers were wired with phase reversal (both of them, not just one) when
using wires with no phase markings. In both cases I was using very familiar
material and had changed the system..a system that was able to deliver
fairly holographic imaging in its previous incarnation. What I heard I can
best be descirbed as a somewhat "hollow" sound in the bass versus a really
dynamic, 3-D bass image. I could hear it on the upright bass and on the
bass drum. In addition, a low male voice on one recording seemed to lose
focus. I traced the wiring and determined the speaker wires were out of
phase (both speakers..one out of phase is a no-brainer). Correcting the
phasing restored the imaging I was accustomed to hearing.

MRJohnson wrote:

Chung wrote in message ...
CCSman wrote:
Some components are said to be phase correct while others invert phase.
Instructions for the latter typically include instructions to reverse the
speaker leads, ie, red the black, black to red, to restore proper phase. As
it's that easy to do, why don't manufacturers of equipment that invert phase
simply wire the outputs of their products 'backwards' (ie, "+" to "-" and "-"
to "+" at the RCA outputs) to restore phase within the product itself?

RCA jacks are not balanced connectors. There is no + and - on RCA jacks.
One side is always at ground.
And not to get off this particular vein - - but what is the real
significance (or true effect) of components (ie-digital
processors/preamps/etc) featuring a "phase-invert" switch which, when
employed, does seem to make some sort of audible improvement (even
from song-to-song within a particular CD)? Is it a relaxation of "ear
fatigue" (although I'm using better than average components), or all
in my (and my wife's) head(s)? (Lucky me-I've got a wife who enjoys
my hobby with me!).

Real significance is some people believe that there is a sonic
difference from phase reversals, someone like yourself!

I cannot tell absolute phase. However, if I were to flip the phase
switch, half the time I *thought* I heard a difference. But if you were
to cover up that switch with black tape, I cannot say what position it
is at by listening.

Chung wrote:
MRJohnson wrote:

Chung wrote in message
...
CCSman wrote:
Some components are said to be phase correct while others invert phase.
Instructions for the latter typically include instructions to reverse
the
speaker leads, ie, red the black, black to red, to restore proper phase.
As
it's that easy to do, why don't manufacturers of equipment that invert
phase
simply wire the outputs of their products 'backwards' (ie, "+" to "-"
and "-"
to "+" at the RCA outputs) to restore phase within the product itself?

RCA jacks are not balanced connectors. There is no + and - on RCA jacks.
One side is always at ground.
And not to get off this particular vein - - but what is the real
significance (or true effect) of components (ie-digital
processors/preamps/etc) featuring a "phase-invert" switch which, when
employed, does seem to make some sort of audible improvement (even
from song-to-song within a particular CD)? Is it a relaxation of "ear
fatigue" (although I'm using better than average components), or all
in my (and my wife's) head(s)? (Lucky me-I've got a wife who enjoys
my hobby with me!).

Real significance is some people believe that there is a sonic
difference from phase reversals, someone like yourself!

I cannot tell absolute phase. However, if I were to flip the phase
switch, half the time I *thought* I heard a difference. But if you were
to cover up that switch with black tape, I cannot say what position it
is at by listening.

I've conducted my own investigation of absolute polarity and my findings agree
with Dick Greiner's research done while he was Dept Chairman of EE at
University of Wisconsin about a decade ago.

Greiner, speaking at a PSACS Meeting held in my home, sais that he had
conducted a deep investigation of absolute polarity including making his own
recordings to assure that polarity throughout a complete system was absolutely
known.

His conclusion was that absolute polarity can be demonstrated over headphones
(and sometimes in rooms) with test tones but no single person or experimental
subject has ever been able to confirm an ability to identify absolute polarity
in a normally reverberant environment with commercial program material or
specially prepared program material where absolute polarity was absolutely
KNOWN.

One attendee argued that "when a kick drum is played you can hear whether the
first wave is a compression or a rarefaction." Greiner asked "have you done
this experiment?"

When the answer was a shoulder shrug Dr Greiner responded "well, I have" and
described an experiment where they used graduate students as subjects on the
50-yard line of an open practice football field. In this case they used a
marching band bass drum which can be struck on either side and at a distance of
several yards blinded (literal blindfolds) subjects were unable to reliably
identify which side of the drum was being struck.

At the end of the meeting I asked the question "so you're saying that no
listener has been able to reliably identify absolute polarity under normally
reverberant conditions such as a listening room?"

He responded "that is true; the typical listening environment completely
scrambles phase and the ability to hear polarity in an absolute sense." He went
on to explain that any phase anomaly that is audible will have a have a
corresponding anomaly in the frequency domain that will have a measurable
dimension.

I tested this by measuring several speakers and reversing polarity and as far
as I could tell none of them showed any frequency response differences when
nothing but the speaker wire was reversed.

There MIGHT be some change if the recording was made with two or three
microphones. Most recordings use multiple microphones so any phase
continuity is lost in the recording.


---MIKE---

(---MIKE---) wrote in message ...
There MIGHT be some change if the recording was made with two or three
microphones. Most recordings use multiple microphones so any phase
continuity is lost in the recording.



This is an inaccurate generalization. Multiple microphones do not
disturb phase continuity as a rule; only *improper* use of multiple
microphones will have a negative affect on phase coherance.

On 9 Nov 2004 01:00:27 GMT, (Buster Mudd) wrote:

(---MIKE---) wrote in message ...
There MIGHT be some change if the recording was made with two or three
microphones. Most recordings use multiple microphones so any phase
continuity is lost in the recording.

This is an inaccurate generalization. Multiple microphones do not
disturb phase continuity as a rule; only *improper* use of multiple
microphones will have a negative affect on phase coherance.

This is incorrect. Standard modern close-miking totally destroys any
phase relationships that may have existed at the listener position in
a live concert, for very obvious reasons. Whether this is audibly
important is another matter, but pan-potted close-miked instruments
simply do *not* sound the same as a 'minimalist' stereo setup such as
that used by Pope Music.
--

Stewart Pinkerton | Music is Art - Audio is Engineering

(Buster Mudd) writes:

(---MIKE---) wrote in message
...
There MIGHT be some change if the recording was made
with two or three microphones. Most recordings use
multiple microphones so any phase continuity is lost in
the recording.



This is an inaccurate generalization. Multiple microphones
do not disturb phase continuity as a rule; only *improper*
use of multiple microphones will have a negative affect on
phase coherance.

I don't follow. If two microphones feed a particular
channel, and they are distance d apart, then for frequencies
multiples of speed-of-sound/d sound sources colinear with
the mics are in phase, but for odd multiples of
speed-of-sound/(2d) they'll be in antiphase.

If you add a delay of d/speed-of-sound that will correct
this effect for sources in one direction, but introduce a
similar effect for sources everywhere else.

--
Jón Fairbairn
http://www.chaos.org.uk/~jf/Stuff-I-dont-want.html (updated 2004-10-13)

"Jón Fairbairn" wrote in message ...
(Buster Mudd) writes:

(---MIKE---) wrote in message
...
There MIGHT be some change if the recording was made
with two or three microphones. Most recordings use
multiple microphones so any phase continuity is lost in
the recording.



This is an inaccurate generalization. Multiple microphones
do not disturb phase continuity as a rule; only *improper*
use of multiple microphones will have a negative affect on
phase coherance.

I don't follow. If two microphones feed a particular
channel, and they are distance d apart, then for frequencies
multiples of speed-of-sound/d sound sources colinear with
the mics are in phase, but for odd multiples of
speed-of-sound/(2d) they'll be in antiphase.



If multiple mics are in fact feeding one particular channel then yes,
the *original* phase relationship of a musical signal will be
altered...but once those signals have been combined onto that channel
the composite signal is phase coherant. And the only reason an
experienced professional recording engineer would sum non-coincident
microphones to a single channel would be to lock in that particular
phase relationship; it's a timbral choice.

Also consider when d=0.

Stewart Pinkerton wrote in message ...
On 9 Nov 2004 01:00:27 GMT, (Buster Mudd) wrote:

(---MIKE---) wrote in message ...
There MIGHT be some change if the recording was made with two or three
microphones. Most recordings use multiple microphones so any phase
continuity is lost in the recording.

This is an inaccurate generalization. Multiple microphones do not
disturb phase continuity as a rule; only *improper* use of multiple
microphones will have a negative affect on phase coherance.

This is incorrect. Standard modern close-miking totally destroys any
phase relationships that may have existed at the listener position in
a live concert, for very obvious reasons.

Standard modern multitrack techniques don't adhere to the temporal
relationships of a live concert *on any scale*. There IS no "phase
relationship" between a saxophone recorded Tuesday in Los Angeles and
a tambourine recorded Friday in Nashville, so there is nothing to
destroy.

Stewart Pinkerton wrote in message ...
On 9 Nov 2004 01:00:27 GMT, (Buster Mudd) wrote:

(---MIKE---) wrote in message ...
There MIGHT be some change if the recording was made with two or three
microphones. Most recordings use multiple microphones so any phase
continuity is lost in the recording.

This is an inaccurate generalization. Multiple microphones do not
disturb phase continuity as a rule; only *improper* use of multiple
microphones will have a negative affect on phase coherance.

This is incorrect. Standard modern close-miking totally destroys any
phase relationships that may have existed at the listener position in
a live concert, for very obvious reasons.

If you consider the phase relationship "correct" for a given position
position of your head in a live concert, merely moving your head will
immediately "destroy" those "correct" phase relationships as well.

If you consider the phase relationships "correct" in a live concert
because you are able to sample a 3-d sound field, recording that
sound field with 2 microphones and reproducing it through two speaker
will destroy those phase relationships. And they will be destroyed
just as surely as recording that sound field with multiple microphones.

It will just be destroyed differently.

Chung wrote in message ...
MRJohnson wrote:

Chung wrote in message ...
CCSman wrote:
Some components are said to be phase correct while others invert phase.
Instructions for the latter typically include instructions to reverse the
speaker leads, ie, red the black, black to red, to restore proper phase. As
it's that easy to do, why don't manufacturers of equipment that invert phase
simply wire the outputs of their products 'backwards' (ie, "+" to "-" and "-"
to "+" at the RCA outputs) to restore phase within the product itself?

RCA jacks are not balanced connectors. There is no + and - on RCA jacks.
One side is always at ground.
And not to get off this particular vein - - but what is the real
significance (or true effect) of components (ie-digital
processors/preamps/etc) featuring a "phase-invert" switch which, when
employed, does seem to make some sort of audible improvement (even
from song-to-song within a particular CD)? Is it a relaxation of "ear
fatigue" (although I'm using better than average components), or all
in my (and my wife's) head(s)? (Lucky me-I've got a wife who enjoys
my hobby with me!).

Real significance is some people believe that there is a sonic
difference from phase reversals, someone like yourself!

I cannot tell absolute phase. However, if I were to flip the phase
switch, half the time I *thought* I heard a difference. But if you were
to cover up that switch with black tape, I cannot say what position it
is at by listening.
But, getting back to the original question . . . what does it do (to
the signal, etc) that COULD lead to a different perception of the
sound? Or, is it possible that the manufacturers of some of the
components I've owned (Theta Basic IIIa, Levinson 380S, Theta Gen Va,
now Theta Gen VIII) just throw this switch in to make SOME consumers
(ie-me) THINK it actually does something, so they can jack up the
price a bit more? Yeah, I know couldn't identify if it was (+) or (-)
phase on a blind test, but I have noticed a difference by (knowingly
myself) using the switch (re-opening the imaging), and my wife
(essentially A-B blind, since she didn't know I had hit the switch)
commenting/asking if I had "turned up the volume on the last song . .
" on more than one occasion. I never bought a component specifically
because it had this feature, but I can't deny that, for whatever
reason, SOMETHING'S happening to the signal. (And why SHOULD it make
a difference?). Is there something screwy with my components, or do
these (and many other) manufacturers put this switch in their
components in the hope that someday I (underlined) will buy it? That
was my question.

MRJohnson wrote:
Chung wrote in message ...
MRJohnson wrote:

Chung wrote in message ...
CCSman wrote:
Some components are said to be phase correct while others invert phase.
Instructions for the latter typically include instructions to reverse the
speaker leads, ie, red the black, black to red, to restore proper phase. As
it's that easy to do, why don't manufacturers of equipment that invert phase
simply wire the outputs of their products 'backwards' (ie, "+" to "-" and "-"
to "+" at the RCA outputs) to restore phase within the product itself?

RCA jacks are not balanced connectors. There is no + and - on RCA jacks.
One side is always at ground.
And not to get off this particular vein - - but what is the real
significance (or true effect) of components (ie-digital
processors/preamps/etc) featuring a "phase-invert" switch which, when
employed, does seem to make some sort of audible improvement (even
from song-to-song within a particular CD)? Is it a relaxation of "ear
fatigue" (although I'm using better than average components), or all
in my (and my wife's) head(s)? (Lucky me-I've got a wife who enjoys
my hobby with me!).

Real significance is some people believe that there is a sonic
difference from phase reversals, someone like yourself!

I cannot tell absolute phase. However, if I were to flip the phase
switch, half the time I *thought* I heard a difference. But if you were
to cover up that switch with black tape, I cannot say what position it
is at by listening.
But, getting back to the original question . . . what does it do (to
the signal, etc) that COULD lead to a different perception of the
sound?

Well, the phase is inverted by 180 degrees, so it all comes down to
whether people are sensitive to the absolute phase of sound or not. I
know I am not.

Or, is it possible that the manufacturers of some of the
components I've owned (Theta Basic IIIa, Levinson 380S, Theta Gen Va,
now Theta Gen VIII) just throw this switch in to make SOME consumers
(ie-me) THINK it actually does something, so they can jack up the
price a bit more?

They throw in this switch to satisfy those who believe that phase
reversals can be perceived.

Yeah, I know couldn't identify if it was (+) or (-)
phase on a blind test, but I have noticed a difference by (knowingly
myself) using the switch (re-opening the imaging),

Well, then the difference is perhaps imaginary, no?

and my wife
(essentially A-B blind, since she didn't know I had hit the switch)
commenting/asking if I had "turned up the volume on the last song . .
" on more than one occasion.

There is always that innocent bystander...

I never bought a component specifically
because it had this feature, but I can't deny that, for whatever
reason, SOMETHING'S happening to the signal.

How can you say that there is a sonic difference for sure, if you *know*
that you will fail the blind test?

(And why SHOULD it make
a difference?). Is there something screwy with my components, or do
these (and many other) manufacturers put this switch in their
components in the hope that someday I (underlined) will buy it? That
was my question.

I hope we have answered it.

Chung writes:
Well, the phase is inverted by 180 degrees, so it all
comes down to whether people are sensitive to the absolute
phase of sound or not. I know I am not.

Doesn't this depend on frequency? For anything above 50Hz
I'm sure I'm not either. For something below 1Hz I'm not so
sure, not having performed a proper experiment. But if I put
my palms over my ears and press, the sensation is distinctly
different from when I pull them off again.

Even if a proper experiment found an effect and put the
boundary somewhat higher than 1Hz, I doubt that it would
have much to do with music.

--
Jón Fairbairn

Chung wrote:
MRJohnson wrote:
Chung wrote in message
...
MRJohnson wrote:

....snip to relevant content, no meaning corrupted ......

Real significance is some people believe that there is a sonic
difference from phase reversals, someone like yourself!

I cannot tell absolute phase. However, if I were to flip the phase
switch, half the time I *thought* I heard a difference. But if you were
to cover up that switch with black tape, I cannot say what position it
is at by listening.
But, getting back to the original question . . . what does it do (to
the signal, etc) that COULD lead to a different perception of the
sound?

Well, the phase is inverted by 180 degrees, so it all comes down to
whether people are sensitive to the absolute phase of sound or not. I
know I am not.

As far as I know no individual has demonstrated an ability to reliably identify
absolute polarity in a normally reverberant environment (like a listening room)
with bias controls implemented. IOW lots of people profess to hear differences
(sometime described as 'large') but even the most ardent advocates have ever
submitted to a real bias controlled test to prove same.

If you really want to get me started ask me privately about my experience with
Clarke Johnson the world's loudest absolute polarity advocate.