Origin of these earphones? I will never know.
They looked like they had been collecting dusts for years.
How do they sound?
First, the ATH- ANC23 has a mini iPod size noise cancelation "box". Without NC on, the earphone sounded OK, may be slightly above average. With NC on, I did not hear a big difference in sound. Then I realize ANC23 is marketed as traveling (airplane) companion (cancel low freq sound?). OK. I could use one.
Second, the Cks55 sounded V-shaped with extra boost in bass (from the external bass chamber), but very pleasant. Great.
Lastly, CKS1000 and CKS1000LTD are identical in sound and design. LTD sports a bright red paint job and has a metal bass chamber. I couldn't tell if the CKS1000 is plastic or metal.
Both have a problem- the right side sound is lower. I tried to burn them in for 1 day. No change. Then I realized the cords came in two sections, the second section has a volume control dial. I removed the volume control section of the cord and tested the sound again. Problem fixed, mostly. I still " think" the sound on the right side is lower. Psychological? I think I need to replace these aged cords (10 years old?).
How do they sound? Great, just like the " reviews" in this thread. I am very happy with them, especially with the extra bass. I went out running with the LTD version and it drew a lot of attention, mainly because it stick out so far from my ears.
Overall. I lucked out with this purchase. Now onto the re-cabling project.