SDA effect in other products?

polkfan38polkfan38 Posts: 360
edited December 2010 in Speakers
After reading some more about the SDA effect, a memory popped into my head. Back in the early 80s, my friends and I were getting into stereos and the all important "boom box". There were a number of makes (Panasonic and Techniques to name a few) that had a switch on them labled "Ambiance" or "Spatial". When activated, the soundstage would go from just in front of the radio to something two to three times it's size in width! Beyond this, it is hard to describe the sound. I still have one of the Panny models with this effect. Could this be the same thing? I believe it sends the signal from one channel back to the other with a very slight delay.
What are your thoughts?
Things are more like they are now than they ever will be!
Post edited by polkfan38 on

Comments

  • heiney9heiney9 Posts: 23,892
    edited December 2010
    No it's not the same thing. Not even close to how SDA works.

    H9
    "Appreciation of audio is a completely subjective human experience. Measurements can provide a measure of insight, but are no substitute for human judgment. Why are we looking to reduce a subjective experience to objective criteria anyway? The subtleties of music and audio reproduction are for those who appreciate it. Differentiation by numbers is for those who do not".--Nelson Pass

    Pass Aleph 30 | EE Avant Pre | EE Mini Max Plus DAC | MIT Shotgun S3 | MIT Z P/C's | updated SDA 1C| SQ Box Touch/Welbourne Labs P/S- Tubes add soul!
  • wayne3burkwayne3burk Posts: 948
    edited December 2010
    Yeah - I'm sure this subject has been brought up before. I believe the Carver C-1 preamplifier has a sonic holography feature that is essentially a crosstalk noise cancelling signal sent to the opposing speaker.....

    http://en.wikipedia.org/wiki/Sonic_holography

    wayne
    Yamaha RX-V2700, EMI 711As (front), RCA K-16 (rear), Magnavox Console (Center & TV Stand), Sony SMP-N200 media streamer, Dual 1249 TT =--- Sharp Aquas 60" LCD tellie
  • AudioGenicsAudioGenics Posts: 2,586
    edited December 2010
    digital filters
    .... " SDA is patented and exclusive to Polk Audio "
  • polkfan38polkfan38 Posts: 360
    edited December 2010
    When was it patented?
    Things are more like they are now than they ever will be!
  • heiney9heiney9 Posts: 23,892
    edited December 2010
    polkfan38 wrote: »
    When was it patented?

    Any clue how to use the internet? Found it in about 10 sec. 12-18-84

    Click here

    H9
    "Appreciation of audio is a completely subjective human experience. Measurements can provide a measure of insight, but are no substitute for human judgment. Why are we looking to reduce a subjective experience to objective criteria anyway? The subtleties of music and audio reproduction are for those who appreciate it. Differentiation by numbers is for those who do not".--Nelson Pass

    Pass Aleph 30 | EE Avant Pre | EE Mini Max Plus DAC | MIT Shotgun S3 | MIT Z P/C's | updated SDA 1C| SQ Box Touch/Welbourne Labs P/S- Tubes add soul!
  • kawizx9rkawizx9r Posts: 5,179
    edited December 2010
    heiney9 wrote: »
    Any clue how to use the internet? Found it in about 10 sec.

    LOL

    That's sig material right there!
    Truck setup
    Alpine 9856
    Phoenix Gold RSD65CS

    For Sale
    Polk SR6500
    Polk SR5250
    Polk SR104


    heiney9 wrote: »
    Any clue how to use the internet? Found it in about 10 sec.
  • heiney9heiney9 Posts: 23,892
    edited December 2010
    I believe the original patent for SDA's has run out..........too lazy to look so don't quote me on that. Surround Bar technology which is based on the SDA process is patented however.

    H9
    "Appreciation of audio is a completely subjective human experience. Measurements can provide a measure of insight, but are no substitute for human judgment. Why are we looking to reduce a subjective experience to objective criteria anyway? The subtleties of music and audio reproduction are for those who appreciate it. Differentiation by numbers is for those who do not".--Nelson Pass

    Pass Aleph 30 | EE Avant Pre | EE Mini Max Plus DAC | MIT Shotgun S3 | MIT Z P/C's | updated SDA 1C| SQ Box Touch/Welbourne Labs P/S- Tubes add soul!
  • polkfan38polkfan38 Posts: 360
    edited December 2010
    UG! Thanks guys. Yes, I could have looked it up. It's more fun to ask in here! What is "sig material"? Are you making fun of me? (I'm laughing)
    Things are more like they are now than they ever will be!
  • heiney9heiney9 Posts: 23,892
    edited December 2010
    polkfan38 wrote: »
    UG! Thanks guys. Yes, I could have looked it up. It's more fun to ask in here! What is "sig material"? Are you making fun of me? (I'm laughing)

    Maybe a little :tongue:

    H9
    "Appreciation of audio is a completely subjective human experience. Measurements can provide a measure of insight, but are no substitute for human judgment. Why are we looking to reduce a subjective experience to objective criteria anyway? The subtleties of music and audio reproduction are for those who appreciate it. Differentiation by numbers is for those who do not".--Nelson Pass

    Pass Aleph 30 | EE Avant Pre | EE Mini Max Plus DAC | MIT Shotgun S3 | MIT Z P/C's | updated SDA 1C| SQ Box Touch/Welbourne Labs P/S- Tubes add soul!
  • kawizx9rkawizx9r Posts: 5,179
    edited December 2010
    polkfan38 wrote: »
    UG! Thanks guys. Yes, I could have looked it up. It's more fun to ask in here! What is "sig material"? Are you making fun of me? (I'm laughing)

    What Brock said, it's worthy of being in a signature (look, I implemented it in mine!)
    Truck setup
    Alpine 9856
    Phoenix Gold RSD65CS

    For Sale
    Polk SR6500
    Polk SR5250
    Polk SR104


    heiney9 wrote: »
    Any clue how to use the internet? Found it in about 10 sec.
  • heiney9heiney9 Posts: 23,892
    edited December 2010
    Actually, I took some time to re-read the patent and it should be a sticky in the vintage forum. It very succinctly outlines what and how SDA performs. It would answer a lot of questions for those who are just discovering what SDA is.

    H9
    "Appreciation of audio is a completely subjective human experience. Measurements can provide a measure of insight, but are no substitute for human judgment. Why are we looking to reduce a subjective experience to objective criteria anyway? The subtleties of music and audio reproduction are for those who appreciate it. Differentiation by numbers is for those who do not".--Nelson Pass

    Pass Aleph 30 | EE Avant Pre | EE Mini Max Plus DAC | MIT Shotgun S3 | MIT Z P/C's | updated SDA 1C| SQ Box Touch/Welbourne Labs P/S- Tubes add soul!
  • polkfan38polkfan38 Posts: 360
    edited December 2010
    Cool. Thanks guys! Just think how cool a portable SDA radio would be!
    Things are more like they are now than they ever will be!
  • nguyendotnguyendot Posts: 3,583
    edited December 2010
    It wouldn't...
    Main Surround -
    Epson 8350 Projector/ Elite Screens 120" / Pioneer Elite SC-35 / Sunfire Signature / Focal Chorus 716s / Focal Chorus CC / Polk MC80 / Polk PSW150 sub

    Bedroom - Sharp Aquos 70" 650 / Pioneer SC-1222k / Polk RT-55 / Polk CS-250

    Den - Rotel RSP-1068 / Threshold CAS-2 / Boston VR-M60 / BDP-05FD
  • wayne3burkwayne3burk Posts: 948
    edited December 2010
    how cool would SDA headphones be???
    Yamaha RX-V2700, EMI 711As (front), RCA K-16 (rear), Magnavox Console (Center & TV Stand), Sony SMP-N200 media streamer, Dual 1249 TT =--- Sharp Aquas 60" LCD tellie
  • newrivalnewrival Posts: 2,016
    edited December 2010
    wayne3burk wrote: »
    how cool would SDA headphones be???

    ha. they have em. theyre called stereo headphones :P
    there is no crosstalk to be cancelled.
    design is where science and art break even.
  • newrivalnewrival Posts: 2,016
    edited December 2010
    You know this brings up an interesting memory... Polk made SDA for cars. does anyone know anything about this????
    design is where science and art break even.
  • heiney9heiney9 Posts: 23,892
    edited December 2010
    newrival wrote: »
    You know this brings up an interesting memory... Polk made SDA for cars. does anyone know anything about this????

    We installed a few killer systems back then, but sadly it never really took off. My memory is foggy but I believe there was a "processor" box all the speakers ran through and it was quite expensive for the day, IIRC. It was pretty cool.

    H9
    "Appreciation of audio is a completely subjective human experience. Measurements can provide a measure of insight, but are no substitute for human judgment. Why are we looking to reduce a subjective experience to objective criteria anyway? The subtleties of music and audio reproduction are for those who appreciate it. Differentiation by numbers is for those who do not".--Nelson Pass

    Pass Aleph 30 | EE Avant Pre | EE Mini Max Plus DAC | MIT Shotgun S3 | MIT Z P/C's | updated SDA 1C| SQ Box Touch/Welbourne Labs P/S- Tubes add soul!
  • polkfan38polkfan38 Posts: 360
    edited December 2010
    SDA everywhere! Yay! Polk really needs to bring it back for the towers!
    Things are more like they are now than they ever will be!
  • napnap Moderator Posts: 1,319
    edited December 2010
    newrival wrote: »
    You know this brings up an interesting memory... Polk made SDA for cars. does anyone know anything about this????

    Yep.
    There was a venture with Hyundai back in the 80's, when those cars were first being sold here. Problem was they were being stolen because word got out that the car stereos sounded so good. Also, there was the Polk Audio ACM (active cancellation matrix) sold as a car audio seperate. I believe it was basically just a passive network. Results when using it were varied. :cool:
  • newrivalnewrival Posts: 2,016
    edited December 2010
    I found something on this: http://www.polkaudio.com/caraudio/products/mm3a/
    I would love to hear this setup
    design is where science and art break even.
  • newrivalnewrival Posts: 2,016
    edited December 2010
    design is where science and art break even.
  • dorokusaidorokusai Posts: 25,231
    edited December 2010
    nap wrote: »
    Yep.
    There was a venture with Hyundai back in the 80's, when those cars were first being sold here. Problem was they were being stolen because word got out that the car stereos sounded so good. Also, there was the Polk Audio ACM (active cancellation matrix) sold as a car audio seperate. I believe it was basically just a passive network. Results when using it were varied. :cool:

    Correct and it didn't work in every vehicle due to the fact the existing sound system was usually awful to begin with. For the most part Polk laid 12v on the side, for many years unfortunately. The later DSP idea from other manufacturers was better but still couldn't fix the underlying problem. I hate to say it but the BOSE systems were one of the first to get commercially and large scale manufacturer oriented. At that point so much was changing in home audio vs car audio that Polk simply missed the curve.
  • TitaniumManTitaniumMan Posts: 93
    edited December 2010
    Howzabout this?
    http://www.vanlspeakerworks.com/quartet.html

    "Ambient recovery system... We use dual voice coil drivers and an additional connection between the speakers to pass the differential information between the two speakers."
  • nooshinjohnnooshinjohn Posts: 18,465
    edited December 2010
    A New Way of Reproducing Stereo Sound



    The next revolution in loudspeaker design comes from the the patent specification entitled "Ambient Expansion Loudspeaker". As the title implies, this technology expands the perceived sound stage to at least right angles relative to the listener position. It could be described as two speaker "surround" sound. It employs the ubiquitous dual voice coil in a novel, seemingly self-evident way.

    The Problem
    The promise of stereophonic sound through loudspeakers depends on the ability of the listener to perceive a difference between the left and right channels. In sensing this "difference" component, the ear should be able to reconstruct the acoustic signature of the original hall or studio as well as localize the relative locations of instruments or voices. The mechanisms involved are the same ones used in listening to live music (or, for that matter, any acoustic event). Sounds coming from the left are perceived first in the left ear, then travel around inside the head (the cranial shield) to the right ear reduced in intensity and arriving later in time. Thus the ear-brain system computes all of this instantaneously and correspondingly localizes a sound on the left.

    This simplification does not explain why early stereo through loudspeakers could simulate credible left-right "ping-pong" effects, but confined them laterally to the space between the speakers without reproducing the slightest sense of the room where the recording was made.

    It seems that the requirements for dimensionalizing sound in the lateral plane involve reflections from the side walls of the recording locale normally situated at right angles to a listener. In live sound these dimensional clues arrive at the listener's ears from reflections at right angles and even behind a listener. The ear-brain employs its phase sensitive mechanism to perceive these late arriving signals and combines them with intensity difference information to construct the subliminal acoustic architecture of the live acoustic event.

    But when reproduced through two loudspeakers located at a finite distance, everything falls apart! The longer wavelengths required to simulate the original event cannot maintain their differential separation because of human physiology. The left and right ears are spaced approximately 8 inches (separated by the cranial shield). At approximately one-half the wavelength of this inter-aural ear spacing the difference information becomes commingled in both ears at about 400 Hz and perceived monophonically.

    This means that even the very highest performing loudspeakers are perceived monophonically at frequencies lower than about 800 Hz. An experimenter can verify this by inserting a variable low-pass filter with cutoffs from 400 through 800 Hz and then switching between "STEREO" and "MONO" on his or her preamp. The switching differences will become increasingly inaudible below 800 Hz and then totally monophonic below 400 Hz.

    The Solution
    Is it even possible to design a loudspeaker capable of supplying "difference" information down to at least 100 Hz? The answer lies in another attribute of the human hearing mechanism called the "precedence effect". This says that two sounds of equal intensity from different locations can be PREFERABLY LOCALIZED if one of them is DELAYED in time. The ear-brain will tend to reject the delayed sound in favor of the earlier arrival.

    By employing dedicated BINAURAL (dual) voice coils in each left and right speaker system, it is possible to route left and right total signals to the "primary" windings and filtered differential L-R and R-L to the "ambient" windings. In this way, the anti-phase differential radiates from the same acoustic source as the primary left and right signals.

    Note that there is NO TIME DELAY, either electronic or acoustic, employed! Precise localization is maintained, accompanied by an enormous increase in soundstage width and depth.


    Taken from their website...
    The Gear... Carver "Statement" Mono-blocks, TriangleArt Reference SE with PS Audio NuWave Phono converter, Walker Precision Motor Drive, ClearAudio Stradivari v2 cartridge and Origin Conquerer Mk3c tonearm, Polk Audio "Signature" Reference Series 1.2TL with complete mods, Pass Labs X1 two channel preamplifier Signed by Poppa himself, PS Audio PerfectWave DAC MkII, Krell Evolution 525a CD Player, Pioneer Elite SC-65, Oppo UDP-205 Blu-ray , Sony XBR70x850B 4k, Polk audio AB700/800 "in-wall" surrounds

  • newrivalnewrival Posts: 2,016
    edited December 2010
    doro, do you have experience with the mm3a or SDA in cars? if so, was it any good?
    I once saw the SDA xover matrix up on ebay, but i had no idea what it was.
    design is where science and art break even.
  • Joe08867Joe08867 Posts: 3,935
    edited December 2010
    I heard an SDA setup in a competition Van in Philly once. It sounded pretty sweet but the whole setup was custom. I can't see it working in most cars as speaker placement is usually compromised due to doors, windows and seats.

    I will say that the Van is question had the best sounding system of the day. The detail it delivered was beyond anyone's expectations.
    WOW!

    That's like working your way through Katie Perry in order to get to Rosie O'Donnell.
  • dorokusaidorokusai Posts: 25,231
    edited December 2010
    newrival wrote: »
    doro, do you have experience with the mm3a or SDA in cars? if so, was it any good?
    I once saw the SDA xover matrix up on ebay, but i had no idea what it was.

    Only twice and it was neat but I've heard much better custom setups that were simply EQ'd better. I don't believe it was quite as plug and play as it was designed to be and by then it was not something that sold well anyways. With the emphasis on front staging being more common, since that does sound better theres no need. DSP eclipses the SDA effect in a vehicle and it even outdoes SDA in a 2CH setup. Polk is already doing a lot of DSP work in the subwooofers and will extend that into more active components down the road.
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