SDA effect

F1nut

K_M wrote: »

But in the case of SDA speakers, there is something un-natural added to the normal Stereo signal.

You can play semantics, but simply adding another row of speakers several inches apart from the main stereo speakers AND having them play a Stereo Difference signal, sure as heck is adding something un-natural to the signal.

Brock explained it very well, so I'll quote his post. Read it as many times as necessary until understood.

SDA is not an effect. It's implemented in a way to cure a naturally occurring acoustical anomaly. That anomaly being that our ears are positioned on the sides of our head and a typical stereo signal from a hi fi rig reaches our ears at different times. SDA works to minimize the delay, thus opening up the listening sound stage. It varies with the material and recording process of the source material.

nooshinjohn

What would a proper ignore list be without K_M being on it.....

K_M

F1nut wrote: »

K_M wrote: »

But in the case of SDA speakers, there is something un-natural added to the normal Stereo signal.

You can play semantics, but simply adding another row of speakers several inches apart from the main stereo speakers AND having them play a Stereo Difference signal, sure as heck is adding something un-natural to the signal.

Brock explained it very well, so I'll quote his post. Read it as many times as necessary until understood.

SDA is not an effect. It's implemented in a way to cure a naturally occurring acoustical anomaly. That anomaly being that our ears are positioned on the sides of our head and a typical stereo signal from a hi fi rig reaches our ears at different times. SDA works to minimize the delay, thus opening up the listening sound stage. It varies with the material and recording process of the source material.

I maybe understand it better than both you guys. Sorry, but outside the forum, it is not as well regarded nor seen as beneficial.

I get EXACTLY what it does, HOW it does it and WHY it does it.
It does Not open the soundstage, but makes it appear to be wider than intended.

You can argue all you want about it, but in the end you are going on a premise that is wrong. I get in a POLK forum no one dares to question anything Polk, but the idea of cross-talk cancellation simply is not needed.

It might sound cool, might make it appear wider and better, and more this and more that, but its not needed on like 95% of recordings.

Most recordings intentionally have the soundstage they way it is, based on not a shortcoming of standard stereo speakers, but based on the soundstage was "created" on standard stereo speakers.

Again, what you fail to grasp, mixing and mastering studios DO NOT USE sda speakers when they mix to get the final soundstage.
If they did it would work FANTASTIC and I would agree.

So you are hearing a soundstage that was created for standard stereo, then played back on speakers that drastically alter that.

The crosstalk thing would work, ONLY IF, they mixed on speakers that HAD crosstalk cancellation also.

Otherwise, you are hearing an exaggerated soundstage.
We went over this a few times in the past, some finally got it, some did not.

F1nut

We get it, you can never admit to being wrong and will argue ad nauseam.

nooshinjohn

Guess it’s time to sell those SDA’s you have in your sig to someone that actually knows what they are and appreciates them...

K_M

"suppose we go to a concert and put a microphone at each of our ears to record exactly what we are hearing. Those recorded sounds contain all of the characteristics of the instruments and voices in the performance. But it is the differences between the sound recorded at our left ear,compared to what is recorded at our right ear, that contains all of the information about the positions of the instruments, the size of the concert hall, etc"


It WORKS in this situation, but what about the other 98% of recordings that are not done this way?

It makes no mention of how almost all pop and rock is recorded. Nor no mention that outside of the above mentioned scenario, of what will occur.

K_M

F1nut wrote: »

We get it, you can never admit to being wrong and will argue ad nauseam.

But all you seem to have is telling people they do not understand or are wrong or can not admit they are wrong, or one line silly quips,
Im willing bet you have nothing to back up what you say.

My Challenge to you.
Explain in DETAIL why SDA would work on processed, multitrack recordings that have no real soundstage but it is created artificially in a studio WITHOUT mics placed where are ears are.

Give it 4-5 paragraphs. I am eager to see what you have to say.
IF it is another silly one line reply, do not waste your time and mine.

F1nut

Why should I explain anything to someone who refuses to answer direct questions requiring explainations all the time. It's your MO and I'm not going to waste my time. Furthermore, you've already received detailed explanations in this very thread.

Tony M

K_M wrote: »

F1nut wrote: »

We get it, you can never admit to being wrong and will argue ad nauseam.

But all you seem to have is telling people they do not understand or are wrong or can not admit they are wrong, or one line silly quips,
Im willing bet you have nothing to back up what you say.

My Challenge to you.
Explain in DETAIL why SDA would work on processed, multitrack recordings that have no real soundstage but it is created artificially in a studio WITHOUT mics placed where are ears are.

Give it 4-5 paragraphs. I am eager to see what you have to say.
IF it is another silly one line reply, do not waste your time and mine.

Two of us within two weeks saying the same thing almost.

Is it the moon or what?

F1nut

Don't you have another of Verb's posts to "like"?

xschop

I think your "difference signal" is what I refer to as anti-phase, others call it "out-of-phase".
I believe the SDA's also employ delayed timing by default, due to SDA driver spacing, creating more soundstage. Biggest example being SDA 2Bs Vs. CRS+ different soundstage widths with same crossovers employed.

gmcman

@edwardsprague did you try the polarity test?

F1nut

Some feel that stereo recording and reproduction itself is an effect, that mono is the correct way to listen to music. I've noted that when an audiophile vinyl recording is released in stereo and mono it's always the mono versions that sell out first. Chew on that a while.

tonyb

F1nut wrote: »

Some feel that stereo recording and reproduction itself is an effect, that mono is the correct way to listen to music. I've noted that when an audiophile vinyl recording is released in stereo and mono it's always the mono versions that sell out first. Chew on that a while.

Very good point, and true.

Playing devils advocate here, the point further tells us that music is different things to different people.....not a big deal in the long run as long as you enjoy what your hearing.

That said, before there were compensation techniques for the way sound reached our ears, everyone enjoyed music with their ears as is, from live music, to recorded music in it's various forms. Nobody complained the left ear was getting more than the right, or visa versa.

The timing techniques used, was simply a way to improve on what you were already hearing. For some it was indeed an improvement, others it seemed a bit more unnatural....and so frickin' what anyway. Just enjoy the music as you see fit, there is no right and wrong way, no right or wrong technique to use.

...and just for giggles, don't we all set up our systems anyway so that the sound reaches our ears at the same time ? Speaker placement is a big deal, right ? Your listening position, room reflections, etc. We take these things into account because why ? So that our ears are in the sweet spot, getting sound as equal as we can to both ears...in the same time frame ?

In reality, most of us already practice the same techniques SDA uses, or at least seek to achieve the same results. Just by different means is all.

mhardy6647

F1nut wrote: »

Some feel that stereo recording and reproduction itself is an effect, that mono is the correct way to listen to music. I've noted that when an audiophile vinyl recording is released in stereo and mono it's always the mono versions that sell out first. Chew on that a while.

There's probably more than a little truth to that.

The stereo effect -- is an effect, if you think about the way the sound of
music is produced vs. the way it is reproduced using two quasi-point source loudspeakers.

The word stereo is taken from the Greek στερεός (stereós, “solid”) and it really is a "trick" to (re)create a three-dimensional soundfield (wavefront) by superposition of two suitable signals from two point sources. Needless to say, an actual musical group in an actual performance space does not create sound this way at all. Stereo is an illusion produced - in the best case scenario - by clever superposition of waveforms.







Along these lines, and in a classic case of synchronicity, there's an interesting an cogent little editorial blurb by outgoing Stereophile chief editor John Atkinson that's appeared on their website just today: https://www.stereophile.com/content/clowns-left-me-jokers-right

I think it's well worth a look in the context of this thread as folks consider these various 'wave mechanics' tricks to enhance, improve, or otherwise alter a reproduced soundfield.

headrott

tonyb wrote: »

F1nut wrote: »

Some feel that stereo recording and reproduction itself is an effect, that mono is the correct way to listen to music. I've noted that when an audiophile vinyl recording is released in stereo and mono it's always the mono versions that sell out first. Chew on that a while.

Very good point, and true.

Playing devils advocate here, the point further tells us that music is different things to different people.....not a big deal in the long run as long as you enjoy what your hearing.

That said, before there were compensation techniques for the way sound reached our ears, everyone enjoyed music with their ears as is, from live music, to recorded music in it's various forms. Nobody complained the left ear was getting more than the right, or visa versa.

The timing techniques used, was simply a way to improve on what you were already hearing. For some it was indeed an improvement, others it seemed a bit more unnatural....and so frickin' what anyway. Just enjoy the music as you see fit, there is no right and wrong way, no right or wrong technique to use.

...and just for giggles, don't we all set up our systems anyway so that the sound reaches our ears at the same time ? Speaker placement is a big deal, right ? Your listening position, room reflections, etc. We take these things into account because why ? So that our ears are in the sweet spot, getting sound as equal as we can to both ears...in the same time frame ?

In reality, most of us already practice the same techniques SDA uses, or at least seek to achieve the same results. Just by different means is all.

Phenomenal post Tony.

TennMan

I don't think SDA is an effect. I think it is an affect. SDA certainly has an affect (impact or influence) on how speakers sound. Think about it.

DarqueKnight

K_M wrote: »

I maybe understand it better than both you guys. Sorry, but outside the forum, it is not as well regarded nor seen as beneficial.

No, you really have very little to no technical understanding with regard to how stereo works...or at least how it was meant and intended to work.

Either something has technical merit or it does not. Acceptance by many is a logical fallacy and is not proof of truth or proof of concept.

Dr. Floyd Toole spent his career in loudspeaker research and development and is the author of an authoritative text titled "Sound Reproduction - Loudspeakers and Rooms". Dr. Toole's text devotes 13 pages to the subject (pages 142 - 155), going into technical detail (with measurements) about the "fundamental flaw in stereo", which is the comb filtering effect that results from a single point source being reproduced by two sound sources. This is otherwise known as "acoustical crosstalk" or "interaural crosstalk".

Dr. Toole is not a member of this forum, nor was he alone in regarding stereophonic music reproduction as a "fundamentally flawed" (his exact words) medium. Indeed, Dr. Harvey Fletcher of Bell Laboratories, who is the person credited with inventing home stereo systems, viewed two channel music reproduction with a phantom center channel "speaker" as an unfortunate compromise and a critical flaw. His original design was a three channel system with a center speaker. A three channel/three speaker stereo system minimizes interaural crosstalk by design because sounds on the left are played through the left speaker, sounds in the center are played through the center speaker, and sounds on the right are played through the right speaker. However, three channel recording media for home use was not an economically viable concept. On the other hand, Dr. Fletcher's three channel stereo systems have been used by the film industry since 1939.

It is really silly and misinformed to state, or imply, that a system designed to remove interaural crosstalk is "dishonest to the intent of the artist" when the very concept of two channel stereo is "dishonest" to the intent of home stereo's inventor. In other words, the Dr. Fletcher never intended for interaural crosstalk to be a part of home stereophonic music reproduction. It is there as a result of economic and technical compromises. Removing interaural crosstalk moves two channel music reproduction closer to the original three channel design performance goals.

Comb filtering, or interaural crosstalk, is an inherent and unfortunate consequence of two channel stereophonic reproduction. It is a distortion artifact which limits stereo imaging. SDA is a subtractive process that mitigates much of the negative effects of interaural crosstalk.

Another logical fallacy is the assumption that something being changed from the way its creators made it must inevitably result in poorer performance...as if nothing can be improved. This thinking is particularly sad and fallacious when most of the people doing studio music production know little to nothing about producing high quality stereo recordings. Most of them just want to make a record that sells in the millions.
Ironically, sometimes the creators of a recorded music production put product out that is totally unrepresentative of what they intended. Unless an artist is consistently selling at platinum quantities, what you hear is more likely the result of time, budget, facility, and personnel constraints, rather than the result of what the artist wanted to put out.

I have encountered this intellectually crippled way of thinking from people who questioned my modification efforts with SDA loudspeakers. These naysayers hold fast to the idea that such modifications turn the speakers into something Polk never intended. What these intellectually crippled naysayers fail to realize is that mainstream commercial products are built to a price point, often with many corners cut which affect performance. When I did my first SDA modification 29 years ago, I did it under the guidance of Polk's engineering and customer service departments, who were very forthcoming in advising me on where they cut corners and on the higher quality parts that should be installed to improve performance.

In the cases of my SDA modifications, those modifications actually moved the speakers' performance closer to Polk's design goals. In the case of passive interaural crosstalk cancellation, such a system actually moves a two channel stereo system closer to the original three channel performance goals.

Schurkey

DarqueKnight wrote: »

Dr. Floyd Toole spent his career in loudspeaker research and development and is the author of an authoritative text titled "Sound Reproduction - Loudspeakers and Rooms". Dr. Toole's text devotes 13 pages to the subject (pages 142 - 155), going into technical detail (with measurements) about the "fundamental flaw in stereo", which is the comb filtering effect that results from a single point source being reproduced by two sound sources. This is otherwise known as "acoustical crosstalk" or "interaural crosstalk".

I was not aware that "comb filtering" was synonymous with "interaural crosstalk".

DarqueKnight

Schurkey wrote: »

I was not aware that "comb filtering" was synonymous with "interaural crosstalk".

With respect to the way conventional stereo loudspeakers operate, comb filtering is synonymous with interaural crosstalk or acoustical crosstalk.

"In signal processing, a comb filter is a filter implemented by adding a delayed version of a signal to itself, causing constructive and destructive interference. The frequency response of a comb filter consists of a series of regularly spaced notches, giving the appearance of a comb."

https://en.wikipedia.org/wiki/Comb_filter

Toole goes into rigorous detail in the reference I cited. He refers to the crosstalk effect as "an important one-toothed comb" which is "a fundamental flaw in stereo". Further, on page 155 he stated:

"But, no matter what kind of loudspeakers are used in what kind of acoustical space, conventional two-channel stereo cannot produce a center image that sounds the same as that from a discrete center channel, even if it is stable and well defined."

heiney9

Thank You DK for explaining it with substance and specificity.

K_M clearly has no clue what she/he is talking about. Just perpetuating false information and flawed suppositions trying to mold her very narrow experiences and skewed beliefs to fit a subject she has zero understanding of.

Of course she/he is always welcome to site concrete information to back up his/her misinformation. But, I'm sure like every other time, she'll back peddle and blame her lack of being able to write effectively as the reason she is misunderstood.

Her knowledge on the subject is so far from wrong fundamentally, she can't even see the light. This is not a personal attack, just a very hard observation on my part.

H9

P.S...All that said above, each person is certainly allowed to like/dislike SDA's and have an opinion about what they hear.

But perpetuating false information and not understanding the basic function of stereo reproduction and SDA to try and bolster a POV stated as fact will always cause these sorts of debates. I use the word debate loosely since the side of the debate K_M falls on has zero credibility when it comes to facts. And by debate I mean a formal discussion of facts.

H9

heiney9

///\\\

DarqueKnight

heiney9 wrote: »

But perpetuating false information and not understanding the basic function of stereo reproduction and SDA to try and bolster a POV stated as fact will always cause these sorts of debates.

If a lie or half-truth is perpetuated long enough and loudly enough and widely enough, it begins to pass for truth.

For example, the unsupported refrain that "SDAs do something to the music that the artists/creators never intended". I have never seen a scientific study or survey of music creators asking them to compare the quality of their music played through conventional and SDA loudspeakers. In the absence of that data, how can one be certain that the artists/creators wouldn't appreciate hearing their music with reduced acoustic distortion?

Before such a study could be done, it would first have to be determined whether the creators know the basics of stereophonic reproduction.

The truth is that two channel stereo is a corrupted and distorted version of the three channel true stereo that was originally invented. SDA technology does a commendable job of simulating three channel stereo. But just because something is more accurate does not mean it will be more desirable to a listener.

Naysayers are typically a lost cause, but these kinds of debates provide some insight for those who have honest intent and a genuine desire to increase their knowledge and understanding in this hobby.

GospelTruth

I always like reading DK's in depth explanations. I appreciate them.

It's been mentioned that SDA speakers are not used in recording studios, so therefore the sound the recording engineers intend on recordings would be best replicated on regular stereo speakers.

That got me to thinking about the setups in recording studios. I Googled images from recording studios and you get speaker placement all over the place. I don't know if there is a "standard" for speaker placement in a recording studio, but from the images I saw there is none. Some are placed to the far left and right of the engineers seat. Some are more directly in front. Either way, I would think the sound would be distinctly different depending on the speaker placement in the studio. The further to the right and left, the more it would be similar to a headphone and the cross talk would change.

Speaking of headphones, that was another item I read about recording studios. Some people advocate for headphone usage when recording and mixing. This seems more about the removal of cross talk and removal of outside noise than just using speakers.

In short, I don't think you can conclude that just because a recording studio uses conventional speakers that you must use conventional speakers to get the same sound (as intended by the recording/mixing engineer). I don't think you'll ever get the same sound that the engineer heard in the studio unless you replicate exactly how he/she had their setup in the first place. Throw headphones into it and there is no way recordings would sound the same.

Here is a link to headphone use in the studio. It also has a picture of the studio and I would say by the speaker setup in the picture is not what most people will have in their home listening rooms.

https://www.headphonesbuyer.com/best-recording-studio-headphones/

Food for thought.

PS. I'm no DK on the science behind these things, but my conclusions seem "reasonable".

ken brydson

heiney9 wrote: »

K_M clearly has no clue what she/he

Careful, got me and Jesse a month in the hole....

heiney9

I wasn't being derogatory at all. I know she has stated her husband uses the same account, that's the only reason I said he/she or him/her because I wasn't sure if it was her or her husband posting. I was addressing both of them and I don't know her husbands name.

I would hope that would be understood?

H9

ken brydson

heiney9 wrote: »

I wasn't being derogatory at all. I know she has stated her husband uses the same account, that's the only reason I said he/she or him/her because I wasn't sure if it was her or her husband posting. I was addressing both of them and I don't know her husbands name.

I would hope that would be understood?

H9

I was joking and used the same reasoning. Still got my pee pee whacked...

DarqueKnight

GospelTruth wrote: »

I always like reading DK's in depth explanations. I appreciate them.

It's been mentioned that SDA speakers are not used in recording studios, so therefore the sound the recording engineers intend on recordings would be best replicated on regular stereo speakers.

That got me to thinking about the setups in recording studios. I Googled images from recording studios and you get speaker placement all over the place. I don't know if there is a "standard" for speaker placement in a recording studio, but from the images I saw there is none.

According to Polk's customer service department, there were more than a few recording studios that purchased SDA 1C and SDA 2B speakers for monitor and playback use, hence the black clad "studio" versions of these models. Some studios also adopted the SDA CRS for monitoring and playback purposes.


At upper left corner: SDA 1Cs used as studio monitors at Virgo Digital Recording Studios, West Hempstead, NY. Photo taken from Virgo's website in February 2002.

When I tried to revisit Virgo's website today, the website had been taken down and the website domain name is for sale. You see a variety of speakers in the picture. Some studios use a very accurate pair of stereo studio monitors to mix and produce music, then use a variety of home market speakers to get an idea of what a particular mix will sound like on that type of speaker.

As you found, there are no standards for studio design and for the types of monitors used and for their placement within the studio.

I think it is safe to say that most studios DO NOT use SDA loudspeakers though. However, that does not mean that playing recordings on SDA loudspeakers is a "bad thing" and "unnatural" because the music was not originally mixed on SDA loudspeakers. Most studios also don't use conventional stereo speakers that are widely used in homes.

Consider these facts:

1. All thoughtfully designed recording studios are designed with flat acoustics to allow accurate monitoring of the recordings. It is very difficult to near impossible to replicate the studio acoustic environment in the typical home. In other words, the listening environment in the typical home IS NOTHING LIKE the listening environment in the typical studio. Therefore, if one is going to criticize SDA speakers for not replicating the studio mixing and monitoring process, the home listeners' room must receive greater criticism because it is even further removed from accurately reproducing what was heard in the studio and it has a large effect on what the home listener hears.

2. High quality speakers purposely built for studio monitor work have very accurate and flat frequency response to allow accurate monitoring of the recordings. Such speakers typically cost in the tens of thousands of dollars and would sound "dull" to the average listener. Speakers purposely built for home stereo reproduction have a frequency response that is designed to "sound good" in a wide variety of home listening environments...and most of them do not require a five figure financial investment. In this regard, conventional two channel stereo speakers sound "nothing like" what the artist/producer heard and created in the studio.

3. Considering the fact that music is recorded and produced in rooms (studios) and with electronics (mixing boards, various types of equalizers) and loudspeakers (expensive studio monitors) that have no similarity whatsoever to what consumers use to listen to stereophonic music, it is silly and irrational to say, or imply, that artists and music producers expect the home listening experience to be a reasonably close facsimile of the studio listening experience.

BMF35

DarqueKnight wrote: »

K_M wrote: »

I maybe understand it better than both you guys. Sorry, but outside the forum, it is not as well regarded nor seen as beneficial.

No, you really have very little to no technical understanding with regard to how stereo works...or at least how it was meant and intended to work.

Either something has technical merit or it does not. Acceptance by many is a logical fallacy and is not proof of truth or proof of concept.

Dr. Floyd Toole spent his career in loudspeaker research and development and is the author of an authoritative text titled "Sound Reproduction - Loudspeakers and Rooms". Dr. Toole's text devotes 13 pages to the subject (pages 142 - 155), going into technical detail (with measurements) about the "fundamental flaw in stereo", which is the comb filtering effect that results from a single point source being reproduced by two sound sources. This is otherwise known as "acoustical crosstalk" or "interaural crosstalk".

Dr. Toole is not a member of this forum, nor was he alone in regarding stereophonic music reproduction as a "fundamentally flawed" (his exact words) medium. Indeed, Dr. Harvey Fletcher of Bell Laboratories, who is the person credited with inventing home stereo systems, viewed two channel music reproduction with a phantom center channel "speaker" as an unfortunate compromise and a critical flaw. His original design was a three channel system with a center speaker. A three channel/three speaker stereo system minimizes interaural crosstalk by design because sounds on the left are played through the left speaker, sounds in the center are played through the center speaker, and sounds on the right are played through the right speaker. However, three channel recording media for home use was not an economically viable concept. On the other hand, Dr. Fletcher's three channel stereo systems have been used by the film industry since 1939.

It is really silly and misinformed to state, or imply, that a system designed to remove interaural crosstalk is "dishonest to the intent of the artist" when the very concept of two channel stereo is "dishonest" to the intent of home stereo's inventor. In other words, the Dr. Fletcher never intended for interaural crosstalk to be a part of home stereophonic music reproduction. It is there as a result of economic and technical compromises. Removing interaural crosstalk moves two channel music reproduction closer to the original three channel design performance goals.

Comb filtering, or interaural crosstalk, is an inherent and unfortunate consequence of two channel stereophonic reproduction. It is a distortion artifact which limits stereo imaging. SDA is a subtractive process that mitigates much of the negative effects of interaural crosstalk.

Another logical fallacy is the assumption that something being changed from the way its creators made it must inevitably result in poorer performance...as if nothing can be improved. This thinking is particularly sad and fallacious when most of the people doing studio music production know little to nothing about producing high quality stereo recordings. Most of them just want to make a record that sells in the millions.
Ironically, sometimes the creators of a recorded music production put product out that is totally unrepresentative of what they intended. Unless an artist is consistently selling at platinum quantities, what you hear is more likely the result of time, budget, facility, and personnel constraints, rather than the result of what the artist wanted to put out.

I have encountered this intellectually crippled way of thinking from people who questioned my modification efforts with SDA loudspeakers. These naysayers hold fast to the idea that such modifications turn the speakers into something Polk never intended. What these intellectually crippled naysayers fail to realize is that mainstream commercial products are built to a price point, often with many corners cut which affect performance. When I did my first SDA modification 29 years ago, I did it under the guidance of Polk's engineering and customer service departments, who were very forthcoming in advising me on where they cut corners and on the higher quality parts that should be installed to improve performance.

In the cases of my SDA modifications, those modifications actually moved the speakers' performance closer to Polk's design goals. In the case of passive interaural crosstalk cancellation, such a system actually moves a two channel stereo system closer to the original three channel performance goals.

YEAH ****!! What he says!!!

hoosier21

BEST THREAD ON THIS FORUM IN YEARS