What exactly is the "SDA" effect?

polkfan38

The term SDA realy has my curriosity. I don't know a whole lot about the SDA SRS line of speakers but I would like to know what the SDA effect realy is. I see there is a interconnect between the two speakers. Now, back in the 80's, I had several boom boxes that had a sound known as "Ambience" (Panasonic) or "Spacial" (Magnovox). It would create a airy feeling to the sound. I believe it took one channel and fed it back to the other with just the right amount of delay, creating this effect. Is this what is going on here?
Thanks

Fongolio

Kind of. SDA's work on the idea that your left and right ear don't hear the left and right speakers the same. Your head blocks part of the sound going to the ear opposite of the left and right speakers. The crossover cable does feed part of the left speaker's signal to the right speaker and vice versa. Most SDA speakers have the main drivers spaced at the average person's ear width apart on a horizontal plane. The idea is basically to eliminate the crosstalk sound created by the shadow effect of your head and the slight difference in time the sound reaches your left and right ears.

The SDA "effect" can be dramatic. A much wider and three dimensional sound stage. I have SDA-1C's and tonight while listening to Peter Gabriel's Shaking The Tree (greatest hits album) on some songs part of the sound actually seemed to be coming form behind me. The sound stage was not only wide and deep but also tall. Some instruments and voices are higher and lower on the "stage" than others. I love it.

Bob Carver invented a similar technology called "Sonic Holography" which achieves very similar results using electronic circuits built in to many of Carver's pre-amps, receivers and stand alone units. The SDA effect although a little more subtle than Carver's approach, to my ears, sounds more realistic. It's also stronger on some recordings than others.

I hope this answered your question, and I hope I got the technical stuff right. Welcome to Club Polk.

Kelvin

Conradicles

All I know is that it sounds really good.

shack

http://www.polkaudio.com/downloads/whitepapers/SDA_WhitePaper.pdf

It explains the current surround gear as well as the original design and what Matt was trying to acomplish with the technology.

dpowell

Conradicles wrote: »

All I know is that it sounds really good.

+1

Hard to explain. Hard to give up once you've heard it.

polkfan38

Thanks Fongolio and the rest. I think that technology is so cool! I am a fan of great sound and hear a lot of awesome stuff about the SDAs. Unfortunately, I don't have the means to have a set up like some 1.2tls and powerfull amps. Or the room! LOL! Maybe some day?
For now I am enjoying my Monitor 40s, Infinity SLs and soon Monitor 60s.

polkfan38

Is Matt still involved with his company? I remember him in the ads standing next to his speakers. I have just not seen anything about him in a long time.

shack

polkfan38 wrote:

Is Matt still involved with his company? I remember him in the ads standing next to his speakers. I have just not seen anything about him in a long time.

Matt is no longer an employee. He may still do some consulting...but I don't know that for sure.

Polk Realigns Top Management As Founder, Other Execs Retire

12/22/2008

Baltimore – Polk Audio has realigned its top management team following the retirements of founder Matthew Polk, president and 16-year company veteran Jim Herd, and COO Gary Davis, who was a 25-year company veteran.

As part of the realignment, Jim Minarik will become Polk’s president, adding to his current responsibilities as Polk’s chairman/CEO and current responsibilities as president/CEO of DEI Holdings, which bought Polk in 2006.

In addition sales VP Ben Newhall, a 25-year Polk veteran, adds responsibilities for marketing and product-line management. Polk veteran Jeff Nemec becomes VP of new product development in charge of engineering, project management, and purchasing. And controller Joe Tristanti becomes COO responsible for operations and finance. The three report directly to Minarik, reducing the number of direct reports to the president’s office to three from five.

In another change, Mark Suskind was promoted to product line management VP from product line manager, reporting to Newhall.

The three retiring executives are leaving the company “because they can and want to,” said Minarik, who also noted that the founders and senior managers of an acquired company don’t usually stay on for more than a year.

“With the three of us stepping aside,” Herd added, “we’re turning back a lot of fixed-cost resources and creating an opportunity to advance other peoples’ careers.” He said he and Davis “guided the transition” and that “we set this up for continuity.

Added Minarik, “We are structuring our go-forward organization to take maximum advantage of the combined 200+ years of specific audio industry experience held by the top 10 members of Polk's continuing management team."

The career advancements, Herd said, “will put a lot of energy into Polk Audio.” Under current management, he added, things haven’t been bad at all. Sales in 2008 “are not down very much if at all” despite the economy and shrinking industrywide speaker sales, Herd noted.

Polk was founded in 1972 by Matthew Polk, George Klopfer, Sandy Gross and Craig Georgi just after graduating from Johns Hopkins University. Co-founder Matthew Polk, who has been employed as an adviser since the 2006 acquisition, “will be available to the engineering group when they want for specific projects,” Minarik noted. George Klopfer left Polk about a year ago.

Another Polk cofounder, Sandy Gross, went on in 1990 to start up Definitive Technology with Don Givogue. Definitive was acquired by DEI in 2004, and Gross remains Definitive president. Minarik is Definitive’s chairman and CEO.

Fongolio

shack wrote: »

http://www.polkaudio.com/downloads/whitepapers/SDA_WhitePaper.pdf

It explains the current surround gear as well as the original design and what Matt was trying to acomplish with the technology.

Thanks Shack. That's an excellent white paper and it explains the effect far better than I do.

Hypnotoad

It's fantastic that what it is!

When looking for new speakers I nearly bought some JBL Monitors, Martin Logans and Magnepans etc.

But once I heard the SDA's I knew they were for me.

polkfan38

Does anyone think we will see the likes of the SDAs again?

hearingimpared

polkfan38 wrote: »

Does anyone think we will see the likes of the SDAs again?

SDA effect is used in their surround bars and a few other speaker setups.

steveinaz

It gives you more of a headphone type sound, where channel interaction is minimized by cancellation.

heiney9

Your question was asked about a month ago. Here's a lot more detailed info. I'm sure if you take a minute or two to search, like I did, you'll find even more info.

http://www.polkaudio.com/forums/showthread.php?t=97360

polkfarmboy

steveinaz wrote: »

It gives you more of a headphone type sound, where channel interaction is minimized by cancellation.

I get this exact same effect from my martin logans but I would love to hear this effect combined with the bass from sda's

Whats the best sda's to buy ?
How much do they generally sell for ?
Was there ever a centre channel so you could have 6 sda's in a HT environment ?

heiney9

polkfarmboy wrote: »

I get this exact same effect from my martin logans but I would love to hear this effect combined with the bass from sda's

Whats the best sda's to buy ?
How much do they generally sell for ?
Was there ever a centre channel so you could have 6 sda's in a HT environment ?

If you use the search function all questions will be answered.

H9