Audiblity of absolute polarity

James Romeyn · « **on:** 19 Feb 2007, 05:41 pm »

On a quality system, w/ in-phase speakers: Is it audible to swap/invert the polarity of both speakers at the amp-to-speaker interface?

No component switch is employed, which might alter the result by adding another circuit.

The speakers must be a confirmed in-phase design: All drivers are in-phase, none is wired out of phase w/ any other drivers (a non-in-phase design would invalidate the test.)

SET Man · « **Reply #1 on:** 19 Feb 2007, 06:02 pm »

Hey!

I voted YES.

I have a Single Driver speaker without xover + SET amps aa So, I guess I met the requirement on your post.

First absolute polarity for system is definitely audible.

As for recording.... since my system lack the polarity switch so I can't do it on the fly. But when I was foolling around with my system trying to get the system polarity right. I did some switching with both audiophile test CD and my regular CD/LPs and yes the deference can be heard. The bass will be easier to hear the difference than higher frequency

A simple phase switch could be easily make but don't want to drill the face of my pre or put another contact in the line. But it would be interesting to find out that is the correct polarity of each CD/LP.... hmmm swtiching polarity for each CD/LP every now that is a too much don't you think?

Yes you can hear the difference. But I think having the system in correct polarity is a must and good enough after that.

Take care,
Buddy

BobRex · « **Reply #2 on:** 19 Feb 2007, 06:42 pm »

Well, I can hear the differences on my RM30s. It took me awhile to get everything right, but once I did, yeah, there's a difference.

Audiovista · « **Reply #3 on:** 19 Feb 2007, 06:55 pm »

I voted YES but have to qualify my opinion:

YES - in a system with Single Ended amplifier (I can hear it)
NO - any other amplifier with distortion of less than 0.2% (I can't hear it)

I'd like to hear opinions of people who work in recording studios - is the absolute phase always maintained? Thinking of it - inceased pressure makes microphone diaphragm move in, while speaker has to move out to increase pressure. One would think that there has to be some inversion between mike and speaker if the absolute phase is to be maintained?

Boris

ted_b · « **Reply #4 on:** 19 Feb 2007, 06:56 pm »

Yes, the difference is sometimes subtle, but especially heard in midbass integration/timing. Get the XLO test disc.
I love it for a lot of reasons (not the least of which is the burn in track....I use it on Squeezebox 3 to break in equipment). The XLO test disc has a number of phase tracks, including the subject here...absolute phase.

XLO test disc

Ted

ctviggen · « **Reply #5 on:** 19 Feb 2007, 07:14 pm »

I have a CD with three different tracks. Each track is recorded in normal and inverted (reverse) polarity (for a total of 6 different songs). I spent about 45 minutes listening to these tracks and could not tell any difference between normal and inverted polarity.

rollo · « **Reply #6 on:** 19 Feb 2007, 07:39 pm »

I voted yes.For me out of phase sounds bloated and not focused,especially the bass.I use SETs and when I reverse the speaker cables with CD I can hear this plain as day and night.
Some people are sensitive to this and others not according to the experts which I am not.Try a Chesky or Ref. Record. CD which are in phase and try it out.Chesky is anal about getting the entire recording chain to be of the correct polarity.His recordings are excellent,the venue another story.
Now the kicker,In my experience some people prefer the out of phase presentation as it tends to expand the sound stage and muffle the sound to a degree to make CDs sound better.Go figure
Not for me however.It just unnerves me to the point of fatigue.
rollo

ted_b · « **Reply #7 on:** 19 Feb 2007, 07:46 pm »

Quote from: rollo on 19 Feb 2007, 07:39 pm

I voted yes.For me out of phase sounds bloated and not focused,especially the bass.I use SETs and when I reverse the speaker cables with CD I can hear this plain as day and night.
Some people are sensitive to this and others not according to the experts which I am not.Try a Chesky or Ref. Record. CD which are in phase and try it out.Chesky is anal about getting the entire recording chain to be of the correct polarity.His recordings are excellent,the venue another story.
Now the kicker,In my experience some people prefer the out of phase presentation as it tends to expand the sound stage and muffle the sound to a degree to make CDs sound better.Go figure
Not for me however.It just unnerves me to the point of fatigue.
rollo

Be careful here...we are NOT talking about out of phase recordings or out of phase speaker leads. Those are where the left is out of phase with the right, and mono recordings become vague, stereo imaging is smeared and non-distinct. This is called out of phase, not inverted absolute phase (the subject of this thread). The out-of-phase issue, to me, is not even subjective. It requires a fix (one speaker is wired incorrectly).

Kevin Haskins · « **Reply #8 on:** 19 Feb 2007, 07:48 pm »

I've not voted in order not to change the results but I'd first say you need to better define the term so people understand what your talking about.

Phase is inverted by every recording ever taken. The microphone's output is out of phase with the acoustic wave it is recording.

There is additional phase shifts that occur from active recording gear (most simple gain stages invert phase) and there are mutiple more in the playback process, including the flip that occurs when the electrical signal is transformed back into an acoustical wavefront. All of those are changes in the "absolute phase" as it took place in the original performance.

macrojack · « **Reply #9 on:** 19 Feb 2007, 07:59 pm »

I was going to vote but decided there was a need for clarification in the question. I think absolute polarity is audible but thankfully I don't hear it.

Audiovista · « **Reply #10 on:** 19 Feb 2007, 08:12 pm »

Every filter in the recording chain adds a phase SHIFT, so now we are talking not only about multiple phase inversions (shift of 180°) but also about cumulative shifts of several degrees, frequency dependent. Real question then becomes - what is the ABSOLUTE PHASE?
Boris

rollo · « **Reply #11 on:** 19 Feb 2007, 08:33 pm »

Ted-b,
That is what I meant,sorry if I did explain it properly.It is inverted polarity that I can detect.My findings are the same as I posted,it just is not as tightly focused as when the polarity is correct.When I changed the Theta 5a polarity switch to 180 as opposed to the zero setting for a particular CD or selection, the change was obvious.
Thanks for the clarification
rollo

Kevin Haskins · « **Reply #12 on:** 19 Feb 2007, 08:39 pm »

Quote from: Audiovista on 19 Feb 2007, 08:12 pm

Every filter in the recording chain adds a phase SHIFT, so now we are talking not only about multiple phase inversions (shift of 180°) but also about cumulative shifts of several degrees, frequency dependent. Real question then becomes - what is the ABSOLUTE PHASE?
Boris

Its also important to define filters. Any device that is bandpass in nature (all drivers, passive devices etc..) provide some sort of phase shift (not just a 180 degree shift or inversion). So now not only do we know that correct Absolute Polarity (meaning no phase inversions from the original recording) is not possible, we don't even preserve relative phase in any playback situation.

The first couple paragraphs of this paper provide a good overview of transducer phase issues and the phase shift that is introduced by even a "full range" driver.

http://www.speakerdesign.net/phase_error/phase.html

James Romeyn · « **Reply #13 on:** 19 Feb 2007, 08:46 pm »

Here's some clarification:

You actually have performed this listening test on a good system.

You actually know for sure the speakers are in-phase.

You listen. You invert the polarity of both speakers.

One way sounds better than the other, or at least is different: vote yes.

You hear no discernable difference: vote no.

James Romeyn · « **Reply #14 on:** 19 Feb 2007, 08:48 pm »

Please shut the theories in the drawer & lock the drawer for this voting.

Theories are not allowed in the voting process.

Please be honest, meaning you have participated in the actual listening test.

Please ignore the theories & find out for yourself.

Kevin Haskins · « **Reply #15 on:** 19 Feb 2007, 08:49 pm »

Quote from: RibbonSpeakers.net on 19 Feb 2007, 08:46 pm

Here's some clarification:

You actually have performed this listening test on a good system.

You actually know for sure the speakers are in-phase.

You listen. You invert the polarity of both speakers.

One way sounds better than the other, or at least is different: vote yes.

You hear no discernable difference: vote no.

Much better definition but I still don't know if my system is good or not. Maybe my system just isn't good enough for me to tell the difference.

James Romeyn · « **Reply #16 on:** 19 Feb 2007, 08:52 pm »

You have either done the actual listening test or your vote is, well, kinda misleading. The point is to get the vote of people who actually have tasted vanilla & chocolate, not guessing.

There is absolutely no need to read anything before performing the actual listening test.

Kevin Haskins · « **Reply #17 on:** 19 Feb 2007, 08:58 pm »

Quote from: RibbonSpeakers.net on 19 Feb 2007, 08:48 pm

Please shut the theories in the drawer & lock the drawer for this voting.

Theories are not allowed in the voting process.

Please be honest, meaning you have participated in the actual listening test.

Please ignore the theories & find out for yourself.

Here is the root of the problem. What is the most valid method to use to find out the "truth".

This is where a lot of controversy is introduced. People separate it into the objective camp vs. the subjective camp. I look at the question as a fundamental philosophical one. It is best phrased as "how do we discern truth". Do we trust our senses or do we trust objective measurements and use them in relation to physical laws we understand concerning the universe?

I know this much about listening to try to determine truth. It involves my brain and it involves a complex philological response that not only differs person to person but differs from time to time in an individual. I know from my own personal experience that I've "heard" things that make no sense in terms of engineering or rational explanation that involve audio engineering. I'm left with the question of how to explain those experiences. Are they experiences that actually physically happen and we are just not able to measure, or are they experiences that are produced by a complex physiological response in my brain? I tend to believe that they are produced between my ears rather than in the physical universe but I don't have any way of proving that supernatural things are not occurring to explain them. Afterall, I believe in God without any absolute physical proof so I'm not consistent even in my own methods.

SET Man · « **Reply #18 on:** 19 Feb 2007, 09:00 pm »

Quote from: Kevin Haskins on 19 Feb 2007, 08:39 pm

...The first couple paragraphs of this paper provide a good overview of transducer phase issues and the phase shift that is introduced by even a "full range" driver.

http://www.speakerdesign.net/phase_error/phase.html

Hey!

Kevin, good article.

Yes, I am aware of the phase shift in full range without any xover.

But it is much less severe than those multi-way speakers with complex xover for sure.

This is a very sensitive issue here. But since we can not control how the recordings are made. The only way for us to do is to try to get it right at the playback. Doesn't matter how many times signal had been reversed if at the end is at the correct polarity than it should sound right.

Quote from: RibbonSpeakers.net on 19 Feb 2007, 08:46 pm

Here's some clarification:

You actually have performed this listening test on a good system.

You actually know for sure the speakers are in-phase.

You listen. You invert the polarity of both speakers.

One way sounds better than the other, or at least is different: vote yes.

You hear no discernable difference: vote no.

Jim, I think I'm still meet your requirement

But you have to keep in mind that this is not easy for those people with multi-way speaker with complex xover... especially those with xovers with different slope in the same speaker

Take care,
Buddy

Kevin Haskins · « **Reply #19 on:** 19 Feb 2007, 09:10 pm »

Quote from: SET Man on 19 Feb 2007, 09:00 pm

Hey!

Kevin, good article. Yes, I am aware of the phase shift in full range without any xover. But it is much less severe than those multi-way speakers with complex xover for sure.

This is a very sensitive issue here. But since we can not control how the recordings are made. The only way for us to do is to try to get it right at the playback. Doesn't matter how many times signal had been reversed if at the end is at the correct polarity than it should sound right.

Actually I can design a multiway system that has better phase response than a full range driver without a crossover. I've done so and listened to the response. I'm not talking out of my physics book here.

I'm also not trying to be "know it all" or condescending. I'm just trying to share some of the things I've learned in a way so that people can see the subject from an complete viewpoint, with a good knowledge of the subject in terms of what we know about physical laws. I consider that a polite and respectful way of sharing my viewpoint and experience but I know there are many people who don't like it. I'm sorry... don't mean to be offensive but I know of no other way of sharing my experience.

Poll

Is polarity audible on a quality in-phase system?

Audiblity of absolute polarity