I finished up the Yammy's and connected source.....My golly , they sound nice...kinda like an L100plus. Very , very foreward , must be from the west coast of Japan .
Everything construction-wise was first rate ( I hate working on cheap-a$$ Infinities- where nothing works right) ..These are easily the best Japanese speakers I've ever heard, wish I had them when living with Pioneer CS77a's for 20 years)
I looked them up on the web, and they are essentially the famous NS-1000 without the beryillium hf and mf...I cant really see why those wud be needed as the NS-690II does very well with paper ones.
The output sound is rated at 90db/1m at 1 watt input, and the frequency response is rated at 35 ~ 20,000 Hz.
If looking for something to compare to...kinda like the 4412's ...but MUCH more foreward ...not a studio monitor