The SX-3 was such a hit in japan that JVC couldn't manufacture it quick enough and people had to wait to get one. So they were very busy satisfying japanese customers, no wonder it was not exported.
Source of my claim: contemporary japanese magazines.
Source of my claim (link):
Translated (formatting is mine):
Okihiko Kanno
Swing Journal November issue (October 1972)
from "SJ's Best Buy Stereo"
The SX3 speaker system is
a hot topic in the audio world right now. It would not be an exaggeration to say that it was the first hit for Victor, who has been making speaker systems for a long time. There is a strong view that Victor's tradition and ability as a manufacturer specializing in audio equipment have borne fruit. However, I ...... that half of the current topic is the excellence of this product, and
the other half is the dissatisfaction of having to wait several months to order because of a shortage of products. When this happens, it seems that the number of enthusiasts who crave SX3 is increasing rapidly.
The fact that the SX3 can't keep up with production leads to an explanation of the nature of this speaker system and the significance of a large manufacturer like Victor making such a product. In other words, this system has a strong hand-built character that requires a great deal of elaborate work. I have always said that audio equipment cannot be the best product based on the theory, design technology, and production technology of the streets, but this system seems to be alive with the high technology that combines the obsession and passion for sound of the creator that transcends such common sense, the trial and error backed by the many ideas and experiments that emanate from it, and combines it into a single product with a high degree of perfection. The creator of this speaker system is Masamichi Hayashi, who is the core of the company's speaker technology, and his passion for making speakers is extraordinary. However, until now, to be honest, despite his passion, exploration efforts, and accumulation of technology, it has not been enough to convince us of the sound of the speakers. It can be said that his unique tenacity has endured the unpopularity of the past, and humbly and carefully returned to the starting line several times to correctly grasp the two characteristics of the speaker as an acoustic converter and the speaker as a speaker that plays music, and created this SX3. At the same time, Victor deserves praise for warmly protecting the free creativity of human beings and giving them room for development. It is no exaggeration to say that without this kind of constitution, we will not be able to survive the coming times as an audio manufacturer. Technology is a systematic product of human accumulation, but it should always be inspired by ideas and move forward. Ideas are the result of creativity, which is a contingent element given to us by God, and is the foundation of all creation. I believe that great ideas come from great talent and the environment in which that talent blossoms. Not only the sound itself, but also the converter of the speaker created by humans is composed of complex elements that have not all been analyzed, so if we only use existing theories and technologies to deal with this, we will only be able to produce a product.
The ideas that can be seen throughout the SX3 and the new positive originality that emerged from a wealth of experimentation are highly commendable from my point of view. However, such an attitude does not mean that it will make a good product, and I do not mean that the SX3 is the best speaker system.
After all, the SX3 was created as a product that benefits manufacturers, so there are many restrictions and compromises. Naturally, it was created under the conditions of a small (but practically medium-sized) bookshelf system, which is the most popular form on the market, with a retail price of less than 30,000 yen, and as a result, there are naturally limits to large systems that can reproduce intense acoustics and music that requires such sounds. However, we assure you that it is one of the best products in this range. 2-way 25cm woofer and soft dome tweeter. The elaborate assembly of the system with elaborate materials and craftsmanship reproduces a smooth, deep mid and high frequency and stereophonic presence based on a very rich and realistic bass.