I am a serious hifi addict - an audiophile per se.
On every visit I manage to visit a number of hi-end hifi shops; at times to just see what new equipment is available for listening and mostly to buy music. Many may not know that Bangkok is considered a haven for audiophile CD recordings. They have a huge collection of high resolution recordings (may it Cds, HDCDs, XRCDs, SACDS). The best places to shop of music that I found have been:
1. Amarin Plaza - opposite Gayson. Houses at least 6 decent shops.
2. Central World - Has a fantastic music shop on the ground floor.
3. Hifi Centre - In the lane next to Big C supermarket.
Emporium and Paragon also have a number of shops. The music shop in Emporium wrapped up the last time I was there. Paragon shops are a bit snooty and not very helpful.
Please share more locations if you are similarly into Hifi. This thread is not for Home Theatre (that's another topic for another day).
Cheers