I have still not gotten a definitive answer. so I will ask the question again.
Is Polk using some variation of the Hafler Principle?
GFX,
Jesse's reference to the SDA white paper should explain it in detail. In short, NO. Matthew Polk patented his SDA technology which is intranural crosstalk cancellation. Forget anything Hafler when it comes to the Polk SDA. No common denominator at all.
Enjoy your SDAs. They are a wonderful speaker that have a signature sound all their own.
Regards,
Actually if you look at the schematics of any of the SDA line speakers, it is almost an identical and very simple circuit. The signal from the positive of both channels drives both sets of the outer SDA array speakers.
They derive a "Difference signal" in the exact same way the Hafler circuit (among other surround effects) achieve the same signal.
That is not to say it is exactly the same, but quite similar.
There is only so many signals you can derive from 2 stereo channels
The sum (what is common to both channels)
The difference (what is unique to each channel)
Left
Right
A great idea and some really nice speakers!
I miss mine at times, but I guess things have changed since I got mine in the 80s!
