still don't really understand SDA...

gmorris

Hello all. As I've still never seen or heard a pair of SDA speakers, I'm still a little puzzled as to what all the fuss is all about.

Someone posted a picture once showing the benefits of SDA technology. I've been told that the SDA cable connecting the speakers has something to do with interchannel crosstalk..... I don't dispute the effectiveness of SDA technology, as many forum members here will attest to it, I just don't understand the allure of it, as I've never been able to hear it.

So, now on to my question. If you could achieve the EXACT same results of SDA technology by using an electronic component, i.e. a DSP mode, would you still be interested? I don't want to start a debate over wheter this can be done or not, this is a hypothetical question.

If SDA could be achieved electronically, would you use it? If you answer YES, then why don't you use DSP modes? (NOT that SDA is a DSP mode, it's just that everyone seems to not only NOT use DSP, but hates DSP)

I hope I've worded this question so it makes sense....

steveinaz

SDA does for stereo what FM did for radio. It gives the sound almost a 3-dimensional quality, it's not at all "subtle" you can readily hear the difference. Kind of similar to the effect you get with Carver's holographic generator---in fact both methods seek to accomplish the same thing, crosstalk cancellation.

For a short period of time I had SDA's (still can't recall the model) and I was running a Carver C-1 preamp. I opted to use the Carver sonic holography feature at the time, but I think it was because of room arrangement reasons. I later abandoned holography all together as I found it too "artifical" sounding for my personal taste.

Pulling from memory, so don't quote me:
What SDA does (in essence) is try to give the effect of headphones; complete isolation of L/R stereo information, creating a floating soundstage. Normally when you listen to conventional stereo speakers, your left ear hears some the right channel information--and vice-versa. SDA attempts to cancel this "crosstalk" by providing small levels of each channel to the other speaker, in an effort to "cancel" its arrival---giving you a more headphone-like experience.

Talk to Russman on this, he is the up-to-date guru on this technology, and can correct If I've mis-spoken above.

danger boy

i guess most DSP modes sound pretty bad. I haven't used them ever... they seem to hollow and fake sounding to me.

Try listening to a CD with the DSP mode of say stadium or church. sounds bad to my ears.

VR3

Only DSP mode I have ever used is.......5 Channel Stereo

gmorris

um...... allright. no one answered my question.

First off, I understand what SDA does, I just haven't ever heard it, so I don't understand why so many want it.

Also, I agree that DSP modes suck. So, along that logic, if SDA could be achieved electronically, would you use it?

Also, if SDA is/was so great, why doesn't Polk still build speakers with SDA technology, and why hasn't anyone else done anything similar? (save for the Carver stuff Steve mentioned above)

Now, please don't anyone get all bent out of shape & misunderstand me. I am NOT bashing SDA, I'm only trying to understand it better, by relating it to something (DSP modes) that I am familiar with.

steveinaz

Originally posted by gmorris

Also, if SDA is/was so great, why doesn't Polk still build speakers with SDA technology, and why hasn't anyone else done anything similar? (save for the Carver stuff Steve mentioned above)

I think no else has incorporated it because it may be patent material...as to why Polk doesn't build/market it anymore? Who knows.

I-SIG

gmorris,

While I have heard the Carver technology, I'm not sure if SDA can be replicate delectronically due to the nature of the design, i.e. additional drivers, etc.

Wes

hoosier21

Originally posted by gmorris
First off, I understand what SDA does, I just haven't ever heard it, so I don't understand why so many want it.

3D imaging, a WIDE soundstage, close your eyes and ""see"" the performer in front of you and the band placed back behind, are thses things you are looking for in a pair of speakers, and to the list, nice tight bass, smooth highs, pretty good power handling, and on the used market and frigging steal, what more is there to ask for??

Originally posted by gmorris
Also, I agree that DSP modes suck. So, along that logic, if SDA could be achieved electronically, would you use it?.

IF (that's a big if) maybe, but I don't see how this could be done, I know the SRT system has a control box that has the SDA level control, but I find it hard to beleive that is the same effect, I have been wrong before. :eek:

Also, if SDA is/was so great, why doesn't Polk still build speakers with SDA technology, and why hasn't anyone else done anything similar? (save for the Carver stuff Steve mentioned above)[/B]

I don't think the audio world received SDA very well, it was a gimik, something weird.. only guessing here, I was not aware of them when they were in the stores, I do remember seeing a pair od CRS+'s in a store but did not take the time to get any details, ask some the old farts around here, maybe they know why Polk quit selling them, I do thing the Home Theater thing killed a lot of stuff during that time.

Now, please don't anyone get all bent out of shape & misunderstand me. I am NOT bashing SDA, I'm only trying to understand it better, by relating it to something (DSP modes) that I am familiar with. [/B]

Think back to when you could (and maybe you still can) switch between mono FM and stereo FM, remember that change in sound,how it widened? When you find a pair and get a demo, then you will know. There is not a DSP that comes close.

VR3

SDA stopped selling because of the market in general.

The market wants a slender speaker -- 8" or under

SDA requires 2 drivers side by side -- so you would need like 3 inch woofers to acheive 8" width.

All based on the market. They make what sales.

RuSsMaN

Shut up Sid, you have NO idea.

Cheers,
Russ

madmax

One point is that SDA is done physically while DSP is done electrically. One is a physical phenominon while the other is an effect. Look at Marshall tube guitar amps. Most of us know their sound. Now look at the solid state versions which "emulate" that same sound. Anyone familiar can tell the difference. Another way to look at it is the Carver Silver 7/9t amps or Sunfire amps which emulate tubes. Here again, they have some of the same characteristics but most can tell the difference between the emulation and the real thing. If SDA were emulated well enough with electronics then many would be just as happy but even at that some of us do not want to play around with the pure signal in that manor. I think that was the audiophile line because they didn't understand the signal was still pure. So no, even if the SDA were reproduced faithfully with DSP I would have no interest in it. At least not for my main HS.
madmax

PolkWannabie

Originally posted by hoosier21
I know the SRT system has a control box that has the SDA level control, but I find it hard to beleive that is the same effect, I have been wrong before. :eek:

The SRT's achieve SDA utilizing the same methodology as any other Polk SDA speaker i.e. passively. Most of the controls in the the SRT control center are for the subs. The SDA control consists simply of normal, wide and off. Wide only differs from normal in the frequency range that the cross talk cancellation is produced over.

hoosier21

Originally posted by PolkWannabie
The SRT's achieve SDA utilizing the same methodology as any other Polk SDA speaker i.e. passively. Most of the controls in the the SRT control center are for the subs. The SDA control consists simply of normal, wide and off. Wide only differs from normal in the frequency range that the cross talk cancellation is produced over.

SDA the old fashion way is done by placing the SDA drivers about 7.5 inches to the outside of the stereo drivers creating a millisecond delay, how far from the stereo drivers are the sda drivers in the SRT? From the picture they look much closer.

Normal and wide controls! Sounds like an electronically produced and controlled "effect"

Doesn't seem like the same thing to me.

Shizelbs

What exactly is crosstalk? Why would someone want to eliminate it? I am sure this is any easy one to answer.

VR3

Since I seem to have no idea I figure I might as well chime in with what I understand as the answer...

Crosstalk I believe is when you can hear the right channel in your left ear, and vise versa

But then again, I have no idea

Russ,

Polk makes what sales. You even said it yourself.
If the SDA would sale...they would make it.

The only speaker that they made over 9" wide in a LONG time is the SRT...

I don't need much more to prove my argument than that. :rolleyes:

jdhdiggs

Crosstalk is basically hearing the left speaker in your right ear and vice-versa allowing you to more easily identify the location of the source sound. SDA cancels out the crosstalk enabling the speakers to create a soundfield that is 180 degrees+ wide instead of just barely outside or between the speakers like most systems.

Essentially, sounds on the left channel will sound like they are coming from off your left shoulder and not the left speaker. Similar effect for the right side as well. All of the "blended" sounds fill in the rest of the soundstage.

steveinaz

Originally posted by Shizelbs
What exactly is crosstalk? Why would someone want to eliminate it? I am sure this is any easy one to answer.

Think in terms of headphones. When you have headphones on, you don't hear anything in your left ear from the right speaker....it's this isolation/effect that gives you the 3 dimensional soundstage you get with headphones.

Larry Chanin

Originally posted by gmorris
Hello all. As I've still never seen or heard a pair of SDA speakers, I'm still a little puzzled as to what all the fuss is all about.

Someone posted a picture once showing the benefits of SDA technology. I've been told that the SDA cable connecting the speakers has something to do with interchannel crosstalk..... I don't dispute the effectiveness of SDA technology, as many forum members here will attest to it, I just don't understand the allure of it, as I've never been able to hear it.

So, now on to my question. If you could achieve the EXACT same results of SDA technology by using an electronic component, i.e. a DSP mode, would you still be interested? I don't want to start a debate over wheter this can be done or not, this is a hypothetical question.

If SDA could be achieved electronically, would you use it? If you answer YES, then why don't you use DSP modes? (NOT that SDA is a DSP mode, it's just that everyone seems to not only NOT use DSP, but hates DSP)

I hope I've worded this question so it makes sense....

Hi,

Yes, Inter-aural crosstalk cancellation can be done rather effectively via digital sound processing. In addition to Carver's Sonic Holography, Lexicon digital controllers do this in their highly regarded Panorama effect. When Lexicon's flagship MC-12 processor was released not too long ago, it didn't include the Panorama effect that was in their previous controllers. However, many Lexicon owners who are audiophiles complained about this omission. As a result it was restored in the first firmware upgrade. (Along with other high-end controllers, Lexicon is known for its upgradability.)

Here's an excerpt from a Lexicon Theory & Design white paper:

When a listener is in the correct spot the Panorama effect provides an almost ideal re-creation of the original recording space. It works by using digital signal processing to cancel the crosstalk between the listener’s ears, effectively spreading the sound from the two front loudspeakers in a wide arc in front of the listener. With the optional addition of rear speakers, Panorama can be startling in its realism.

I can attest to the quality of the Lexicon processors I have two, the MC-1 and the MC-8. I can't afford the MC-12 which lists for around $9,000. I guess the point I'm making is that all DSP processes don't have to sound cheezey.

Nevertheless, as much as I love the magic the of Lexicon surround processing, I have never used the Panorama effect. Why? I have SDA-1Cs for my main speakers. Since the SDAs and the processor are attempting to do the same thing it is not possible to use the Panorama effect with SDA speakers. In addition I have chosen not to cripple my SDAs by turning off their dimensional drivers.

I have discussed this on Lexicon forums a number of years ago and those folks who have experienced both approaches were impressed with either approach. However, they felt the SDA's sweet spot was broader than the Panorama effect. (To setup Panorama requires calibrating the sounds at single central location.)

So while I can't address your question directly from first-hand experience I do have an opinion.

Larry

TroyD

As far as SDA goes, you just have to hear it. I was as skeptical as they come about it but it is astounding. That said, the soundstaging wouldn't mean much if the speaker itself sounded like crap but that's just not the case.

I've never heard the Lexicon processors but I have Carver's Sonic Holography and, IMHO, the effect isn't nearly as convincing as SDA. I'm not saying SH is bad at all but it doesn't achieve the same level of soundstaging that SDA does.

BDT

gmorris

Originally posted by madmax
If SDA were emulated well enough with electronics then many would be just as happy but even at that some of us do not want to play around with the pure signal in that manor. I think that was the audiophile line because they didn't understand the signal was still pure. madmax

IS the original signal still intact? Again, I'm not in a position to dispute this claim, I just am curious as to what others think.

TroyD

Yes, the original signal is still in tact.

BDT

madmax

AND the crosstalk signal has NOTHING added to it. Pure, just like I said.
madmax

I-SIG

Originally posted by madmax
AND the crosstalk signal has NOTHING added to it. Pure, just like I said.
madmax

Other than being put ever so slightly out of phase to create the cancellation, of course.

Wes

madmax

What a masterpiece polk created! Those silly audiophiles of old didn't know what hit them so they retaliated with whatever they could think of. Effects, trickery, non-pure, not as the artist intended, you name it. (And that was without listening to them!!!)
madmax

jmasterj

Whenever I see "SDA" I just have to get involved in the post. I really loved the ones I use to own. I too believe the original signal is still intact. You really have to hear them to experience the Stereo Dimensional Array's open, deep sound stage. It allows you to hear clear stereo separation even off center, and many a day I could swear I heard sounds that seemed to originate from behind me. I am so passionate about these speakers that I have decided that I will not buy any other type of speakers from Polk. I brought the current system I have looking for the SDA sound, and even though it's multi-channel it doesn't come close to a two channel SDA system.
I don't mean to sound bitter, just unsatisfied. If I can't get the speakers I want , well then I'll just keep what Iv'e got. I use to just buy a lot of equipment just to hear what it sounds like, then I'd sale, or trade for something else. I simply can't afford to throw money away like that today...

bikezappa

Gmorris

You ask a good question. I have 5 SDA models and they all sound different in different rooms. I don't understand why this effect couldn't be done electronically. In the past Polk didn't have the computor processers they have presently. I think, and I'm only guessing here, that this effect could be done with a computor processer. Raife what say you the king of SDA. Some one please answer this question because I haven't.

George Grand

Without saying which system is better, I WILL go out on a limb and say that Carver Sonic Holography pre-dates SDA so settle down Max.

A lot of companies tried to address interaural-crosstalk LONG before Polk or Carver. They got the most press, that's all.

There is so much interaural-crosstalk cancellation going on in todays products it's amazing. Sony SRS is one system. Hughes Aerospace came out with another. You almost cant buy a tv monitor that doesn't have it. Sometimes it's called "Expanded Stereo" or "Wide". I have a piece of **** 26" RCA that has speakers 8" apart that sometimes throw images 5 feet to the right of the screen.

Headphones is almost a good comparison to holograms or SDA, except with headphones you still get a little cross-talk through your jawbone. And that's a fact Jack.

I happen to prefer the holograms.

George Grand (of the Jersey Grands)

George Grand

Just for **** and giggles, have I mentioned that Polk apparently paid some money to Carver way back when? Regarding Sonic Holography and SDA?

This was discussed here over 5 years ago. Little infringement going on, Carver sued, Polk parted with some cash. I was TOLD it was because it was cheaper to pay than go to court.

George Grand (of the Jersey Grands)

Terrax

Almost all good speakers can create to a certain degree a holographic effect. As long as you have the placement right. I have been experimenting with speaker placement for a long time, and have found an amazing amount of difference in the way speakers create soundfields. Some do this better than others, dipolar types seem better at doing this than conventional boxes. Transparant, soundstage, depth, width, height, is about 3 dimenional sound. I haven't heard the SDA effect myself, but, I would love too.

madmax

Originally posted by George Grand
Without saying which system is better, I WILL go out on a limb and say that Carver Sonic Holography pre-dates SDA so settle down Max.

Yea but Polk is the first one (and last so far that I know of) who did it correctly...

madmax

I must admit I like the SRS system a little. It sounds similar but is really quite different. Things sound spread out but by different amounts on different material. Good try though...

George Grand

That's going to depend on one's interpretation of correct.

George Grand (of the Jersey Grands)