At this point, rather than let this thread leave a future NS-1000x researcher hanging, I'm going to try to convey as much of what I've found as possible. As I said, they are closer to the NS-2000's than the NS-1000M's, so I'm going to compare and contrast them.
I think one of the reasons these speakers are so greatly misunderstood is that, AFAIK, they were not sold in the US. I cannot find any US marketing materials. I was able to find Japanese ones though:
http://www.niji.or.jp/home/k-nisi/ns-1000x.html
I've tried running that through multiple translators, and what this document is doing mostly is stating how the parts of the speaker are derived from the technology used in the NS-2000's.
The NS-1000X began manufacture in 1984, the NS-2000 in 1982, the NS-1000M in 1974.
The NS-1000XW is the same speaker as the NS-1000X but with a natural finish instead of painted black.
Cabinet:
- The 2000 and 1000X both have thicker particle board.
- The 2000 and 1000X both have rounded front baffles to minimize diffractions.
- The 2000 and 1000X both have the drivers vertically aligned.
- The 1000X has a "bi-cabinet" design with a woofer chamber integrated into the bracing.
- There are no meaningful similarities between the 1000M and 1000X cabinets.
Drivers:
Woofer:
- The 2000 and 1000X both have carbon fiber woofers with similar structure and manufacturing processes. The 1000M has a paper woofer.
- The 2000 has a 33cm woofer, the 1000X has a 30cm woofer. The 1000M has a 30cm woofer.
- The 2000 and 1000X both have OFC in the woofer voice coil.
- The 2000 and 1000X both have stronger strontium magnets optimized with FEM
- The 2000 and 1000X both have the same type of surround, I believe. The translation seems to flip flop on this depending on where I get it.
Midrange and Tweeter:
- Part numbers for all models
Tweeters: NS-1000M: JA-0513 NS-2000: JA-0526A NS-1000X: JA-0548
Midranges: NS-1000M: JA-0801 NS-2000: JA-0802A NS-1000X: JA-0803
- The 2000 and 1000X both have OFC wiring
- The 2000 and 1000X both have stronger strontium magnets
- The 1000X and 1000M have the same size magnets, the 2000 has larger magnets
- The 2000 and 1000X both claim the manufacturing of the beryllium improved over time leading to better dispersion characteristics.
Crossover:
- The 1000X and 1000M have the same crossover schematic, including component values
- The 2000 and 1000X have components hard wired together and do not use PCB's.
- The 2000 and 1000X have the physical spacing of inductors maximized to reduce interference.
- The 2000 and 1000X have OFC wiring.
- The 1000X has binding posts, the 1000M has spring clips.
Oddly, in my research, I found that most people consider the NS-1000XW to be smaller versions of the NS-2000, whereas most people consider the NS-1000X to be an updated version of the NS-1000M. While both are true to a degree, its nonetheless amazing what color can do to one's perception.
If anyone finds something to be incorrect, please reply or message me. I did amass this from a bunch of translated sites for the most part.
Sources:
http://www.niji.or.jp/home/k-nisi/ns-1000x.html
http://audio-heritage.jp/YAMAHA/speaker/ns-1000x.html
http://www.kameson.com/audio/NS-1000X.htm