I'm going to pop in here and see if this thread is still alive. I have been researching the Yamaha NS-6490 speakers, and I have been reading the owners reviews in Amazon and other outlets.
What is interesting to me is that this model is acoustic suspension with an 8" woofer. My AR4x speakers sounded great with an 8" acoustic suspension woofer so I was curious how these sounded. Reading the reviews of
people who sounded knowledgable the Yamahas got very nice marks averaging 4.5 out of 5 points. They are not small speakers, measuring 10.5 inches wide by 16.25 inches high and 13.25 inches deep, They are actually larger than my KEF Q300 speakers which are 8.3 inches wide by 14 inches high and 11.9 inches deep. That is getting into big boy territory.
They are certainly smaller than the older AR4x or Dynaco A25 speakers. Rated at 8 ohms impedance and 90 Db efficiency they would present an easy load to just about any amplifier or receiver.
I think they would mate perfectly with my Yamaha R-S201 receiver or my A-S500 amplifier. The specs say they go down to 45 Hz which I think is decent for most music.
One user reported his speakers developed a "Rattle" and I suspect he was overdriving them trying to get a bomb blast in a movie, I think if that is what floats your boat a subwoofer should be used.
My sense, from reading the reviews, is that I feel they could be more forward sounding than the AR4x speakers and not as bright as Klipsch speakers, but that is only my guess.
I might have purchased them in the future just so I could hear what they really sound like and a majority of sellers has them for $129 a pair with free shipping. Unfortunately those dimensions are a real problem for me at this time so I am going to pass on them. I am hoping that any AKer who does get them will give us a full report on them.
OK, back to bed!