SDA

K_M

DarqueKnight wrote: »

K_M wrote: »

Interesting to see what they will come up with for sure!

But I have to wonder, outside this small forum, how well it would go over.
Most audiophiles I know, would never consider this a valid way to listen to 2 channel music.
Same with tone controls, equalizers, or DSP sound enhancements, it is effectively not keeping the signal pure and accurate, but adding an effect to what was already there.

Its fun at times, but think it's time has come and gone.

Actually, SDA is the exact opposite of what you stated. Rather than adding an effect that was not there, it GREATLY DIMINISHES the unnatural comb filtering effects of interaural crosstalk. That is why SDA loudspeakers were/are called "true stereo loudspeakers". In brief, the left and right speaker of pair of conventional stereo loudspeakers each produce a delayed crosstalk signal at the opposite ear that diminishes the perception of stereophonic, three dimensional sound. When this crosstalk signal is diminished, the reproduced sound is more faithful to a live sound field full of individual point sources.

It is actually quite laughable and quite ridiculous to say that SDAs are an "invalid" way of listening to 2 channel music when the comb filtering effects of conventional loudspeakers significantly mask the spatial information that is in the original performance and in the original recording. This is a perfect example of "the lie becoming the truth".

The attached technical article by Matthew Polk describes SDA in detail.

The effects of interaural crosstalk are also discussed in detail in section 9.1.3 (pages 151-155) of Dr. Floyd Toole's book, "Sound Reproduction". The title of that section is
"An Important One-Toothed Comb—A Fundamental Flaw in Stereo".

The article you cite, is where the mistakes are.................

ZLTFUL

I am glad we have people here who know more than people like Matthew Polk and Floyd Toole...

DarqueKnight

K_M wrote: »

SDA speakers are not even remotely considered when mixing and mastering.
All the choices they make with regards to soundstage, and placement of instruments and sounds are done with a different set of standards in place.

The truth is that Polk made the SDA 2B, SDA 1B, and SDA 1C in black vinyl clad "studio" versions that were used by some some recording studios. Here is a picture of an SDA 1C installation in a recording studio:


Recording studio with SDA 1C studio monitor at left.

You are really not saying anything that others, with limited technical understanding similar to yours, have not said before.

K_M wrote: »

You failed to address, why recordings are not made in the manner that Polk advertised they were.

If they were made that way, the SDA effect would be more viable, but as it is, almost no recording have ever been made with 2 microphones 7" apart where are ears are.

That is the flaw in the SDA is accurate argument.

The flaw is in your misunderstanding. If you had bothered to actually read the text of the article rather than just look at the pictures, you might have understood that an example of a simple binaural recording technique was used to describe the effects of interaural crosstalk and ways to mitigate it.

Stereo is not limited to just two channels or two microphones, whereas binaural recording is.

Stereo is meant to reproduce multiple point sources in a sound field. This typically requires more than two microphones. Polk's interaural crosstalk cancellation technology is meant to more accurately reproduce the multiple point sources in a stereophonic recording. The technical paper used an example of two microphones, in a binaural configuration, for simplicity of explanation.

K_M wrote: »

They make an assumption that is not true.

No, you made an assumption based on looking at pictures rather than reading and understanding the text.

K_M wrote: »

I have nothing against the SDA effect, it is a great idea, sounds great at times, but it is based on a flawed premise.

SDA's premise is scientifically valid. It is conventional stereo, and the workarounds that recording studios use to attempt to mitigate its comb filtering effects, that is a flawed premise.

F1nut

Like I said, KM doesn't understand.......well, anything about SDA. Still calling it an effect when in fact non-SDA speakers are the ones presenting an effect or perhaps more accurately, a false presentation.

You, KM are wrong in thinking Polk dropped SDA because at was a failure. Polk has been and continues to use SDA technology in many of their products and quite possibly will offer 2 channel SDA speakers once again.

pitdogg2

Polk soundbars are just one where they have used SDA IIRC

DarqueKnight

F1nut wrote: »

Like I said, KM doesn't understand.......well, anything about SDA. Still calling it an effect when in fact non-SDA speakers are the ones presenting an effect or perhaps more accurately, a false presentation.

Well, when a lie/design defect/inherent flaw has been accepted for decades and generations, and someone comes along with the musical truth, I can understand how that truth would be difficult or impossible to accept.

K_M

Okay so 2 Fanboys of SDA I get it, I will move on...

Neither of you were able to answer what I asked, still.

FTGV

SDA is a clever simple approach to reducing some of the limitations in stereo reproduction.The purely acoustic approach to crosstalk cancellation is to my mind far more desirable than the electronic manipulation used by the likes of Carver's Sonic Holography.With the SH device the signal path will be routed through numerous cheap opamps so the signals integrity will be undesirably altered.From a purists view the SDA is a more elegant solution.

nooshinjohn

K_M wrote: »

Neither of you were able to ask what I asked still.

Proof positive you do not yet have the ability to compose a proper sentence, much less understand the information contained within one. Back to your cell, your highness. (Ignore list for those in Rio Linda.)

K_M

F1nut wrote: »

Like I said, KM doesn't understand.......well, anything about SDA. Still calling it an effect when in fact non-SDA speakers are the ones presenting an effect or perhaps more accurately, a false presentation.

You, KM are wrong in thinking Polk dropped SDA because at was a failure. Polk has been and continues to use SDA technology in many of their products and quite possibly will offer 2 channel SDA speakers once again.

I never said they dropped it cause it was a failure.
They dropped it cause it did not do well enough to make a profit.

You are missing my point, too busy trying to defend something or bash me. The idea is good, it sounds good, but it is simply not really doing what you guys think it is doing.

No need to get into it more, one either thinks its great or thinks it is not so great.
My comments are based on me understanding things, I think you do not understand.

FTGV

K_M wrote: »

... but it is simply not really doing what you guys think it is doing.

If you have some further insight that Mr Polk has not disclosed than please enlighten us.

K_M

nooshinjohn wrote: »

K_M wrote: »

Neither of you were able to ask what I asked still.

Proof positive you do not yet have the ability to compose a proper sentence, much less understand the information contained within one. Back to your cell, your highness. (Ignore list for those in Rio Linda.)

Okay Princess Petty.

nooshinjohn

K_M wrote: »

No need to get into it more, one either thinks its great or thinks it is not so great.
My comments are based on me understanding things, I think you do not understand.

Jesse and DK have forgotten more than most of us will ever know about this stuff and understand the workings of SDA's because they learned all about it from the guys that built it to begin with. To say they don't understand only proves your ignorance of the subject, and your lack of reading comprehension.

xsmi

So are these not viable microphone placement patters for stereo recording in concert halls and such?

F1nut

K_M wrote: »

F1nut wrote: »

Like I said, KM doesn't understand.......well, anything about SDA. Still calling it an effect when in fact non-SDA speakers are the ones presenting an effect or perhaps more accurately, a false presentation.

You, KM are wrong in thinking Polk dropped SDA because at was a failure. Polk has been and continues to use SDA technology in many of their products and quite possibly will offer 2 channel SDA speakers once again.

I never said they dropped it cause it was a failure.
They dropped it cause it did not do well enough to make a profit.

You are missing my point, too busy trying to defend something or bash me. The idea is good, it sounds good, but it is simply not really doing what you guys think it is doing.

No need to get into it more, one either thinks its great or thinks it is not so great.
My comments are based on me understanding things, I think you do not understand.

Right, that's why they were in production from 1982 to 1992.

As to not answering your single question, I'm still waiting for you to answer the one I've asked you multiple times.

Oh, I understand your understanding. You simply don't understand and are trying once again to wiggle your way out of something you started without a firm grasp of the subject matter.

nooshinjohn

I have had many speakers, but only two had my dogs barking from the middle of the sweet spot, my big Maggies and my 1.2TL's

FTGV

Wow

Nightfall

SDA's are for hack audiophiles.

I miss my 2B's.

heiney9

Those that don't know, don't know they don't know.

H9

heiney9

K_M, going behind the scenes whining to another member about this issue will get you no where. You don't know what you are posting about in relation to how SDA's work and how they are much more natural than regular stereo.

It's one thing to have an opinion one way or another after personal use, but you need to understand the technology before you go around spreading misinformation and misconceptions.

H9

K_M

I understand completely how and why it works.
But:
When recordings are mixed and mastered, the location of sounds/instruments/reverb and sound stage are "created", by using combinations of Phase, level, and panning added reverb etc, with the inherent interactions between normal stereo speakers and human hearing ALREADY factored in,

In other words, "Salt" was already added (by using phase, panning and reverb in combination) in the mixing and/or mastering stages of the recording to compensate for the issue that SDA was created to fix.

tonyb

K_M wrote: »

I understand completely how and why it works.
But:
When recordings are mixed and mastered, the location of sounds/instruments/reverb and sound stage are "created", by using combinations of Phase, level, and panning added reverb etc, with the inherent interactions between normal stereo speakers and human hearing ALREADY factored in,

In other words, "Salt" was already added (by using phase, panning and reverb in combination) in the mixing and/or mastering stages of the recording to compensate for the issue that SDA was created to fix.

To some extent, your right, but as DK noted, it's a removal process, not an added one. It removes those things you mentioned, or some of that, to return the recording to it's natural process.

I get you may not like it for what it is, all fine and good, but why keep harping on those who do ? Audio certainly isn't a one size fits all box.

xsmi

K_M,

I've taken 2 classes in recording and I've never heard of an effect that would cancel interaural crosstalk.

heiney9

K_M wrote: »

I understand completely how and why it works.

No, you don't based on your interaction here. I will leave it alone now as you are firmly entrenched in your belief and are unwilling to learn something new.

Again, audio is a personal journey.

Enjoy your journey

H9

K_M

nooshinjohn wrote: »

K_M wrote: »

No need to get into it more, one either thinks its great or thinks it is not so great.
My comments are based on me understanding things, I think you do not understand.

Jesse and DK have forgotten more than most of us will ever know about this stuff and understand the workings of SDA's because they learned all about it from the guys that built it to begin with. To say they don't understand only proves your ignorance of the subject, and your lack of reading comprehension.

So these 2 guys on a Polk forum are completely right, let me get this, because they talked to a Guy/s that created SDA to market a speaker to sell and make a profit for a company?

I suppose that ends the discussion.

Do you even get a hint of Fanboy bias ever?

heiney9

xsmi wrote: »

K_M,

I've taken 2 classes in recording and I've never heard of an effect that would cancel interaural crosstalk.

There is something called the Waterloo Effect that electronically manipulates the audio signal to somewhat mimic some of what SDA's do naturally.

Jump over to the Steve Hoffman board, there's some info there. I haven't explored the subject completely, but on the surface it seems to try and minimize inner aural crosstalk or at the very least expand the soundstage.

Qsound was another that really manipulated the recording. Listen to Madonna's - Ray of Light, holy cow talk about a no boundaries recording. But it's all electronic and Qsound gets old fast since it's so unnaturally extreme. SDA's you can pinpoint instruments and vocals. Qsound has a "swirling effect" that has sounds coming from everywhere (like surround sound). Not natural at all.

Qsound recordings on SDA's are a trip and half! Like LSD without the side effects....lol

H9

FTGV

K_M wrote: »

I suppose that ends the discussion.

Well the discerning dog argument should,

heiney9

nbrowser wrote: »

I'd opine the SDA technology in the new Magnifi Mini astounds quite nicely in such a smallish bar.

Just purchased one, can't wait to hear it. My TV speakers are horrible (as most are these days) and it's just not practical to have the main rig on all the time.

I bought it not only for the fabulous reviews, but because of the evolving SDA technology that's part of the 6 speaker center channel.

H9

Jstas

Just wondering out loud here but what are your qualifications, @K_M that you can so unequivocally state an article written by the guy with Johns Hopkins degree, multiple patents and several peer-reviewed and published documents on the subject is mistaken? In other words, show your work, please? 'Cause you can't just say something is wrong and leave it at that without showing any proof of your statements. Especially when the article in question that you are stating is mistaken actually shows the work behind the proof of the technology.

If you're going to use the logical fallacy of an appeal to authority and furnish no proof of these mistakes then at least furnish some proof of your authority. Otherwise, your entire "argument" is just another logical fallacy called "burden of proof". If no one here had given any proof as to the efficacy of the SDA tech then it'd just be hearsay and a school yard fight. However, a published document explaining the tech has been provided to which you stated that it is flawed yet gave no evidence of these flaws. Instead, you used a straw man argument to push the burden of proof off to your opponents by calling them fanbois. (It's also a few kinds of ad hominem attacks, a spurious correlation and an appeal to ridicule but I don't feel like explaining all of them) You can't, honestly, expect to win an argument by attempting to force your opponent to prove your position for you by calling them a fanboi and mocking them for it. Even if they did fall for your bait, all it would prove is that there is validity to their fandom but your argument would still be left unproven.





On a side note, I disagree that you need multiple drivers to make a good loudspeaker.

I have a pair of SDA 2B's (Matt Polk's favorite, BTW, told me so himself when I begged him to sign both my passive radiators!) and they have a total or 3 drivers and 1 passive radiator on each speaker. One tweeter, one stereo driver, one SDA driver and one passive radiator. I don't think any other SDA speaker has fewer drivers. That makes the 2B's insanely simple to drive for such a complicated crossover network. I've run them with as little as 20 watts per channel. They seem to like about 70 watts per channel best. They get plenty loud, have plenty of impact and the SDA effect isn't diminished at all but with the simple 2-way design, they are quite accurate.

They are also unmodded. As they came from the factory.

mhardy6647

lightman1 wrote: »

I'm thinkin' -- bachelor.
The gene pool, thankfully, does have a way of protecting itself.